WO2024034076A1 - Superabrasive grain and grindstone - Google Patents

Superabrasive grain and grindstone Download PDF

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Publication number
WO2024034076A1
WO2024034076A1 PCT/JP2022/030622 JP2022030622W WO2024034076A1 WO 2024034076 A1 WO2024034076 A1 WO 2024034076A1 JP 2022030622 W JP2022030622 W JP 2022030622W WO 2024034076 A1 WO2024034076 A1 WO 2024034076A1
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WIPO (PCT)
Prior art keywords
superabrasive
abrasive grain
less
mass
grindstone
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PCT/JP2022/030622
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French (fr)
Japanese (ja)
Inventor
修一 網野
健 山村
真人 道内
克己 岡村
Original Assignee
住友電気工業株式会社
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Priority to PCT/JP2022/030622 priority Critical patent/WO2024034076A1/en
Publication of WO2024034076A1 publication Critical patent/WO2024034076A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K3/00—Materials not provided for elsewhere
    • C09K3/14—Anti-slip materials; Abrasives

Definitions

  • the present disclosure relates to superabrasives and grindstones.
  • a grindstone containing abrasive grains and a binder is used as a tool for precision machining.
  • BACKGROUND ART Conventionally, a grindstone in which abrasive grains made of diamond, cubic boron nitride, alumina, silicon carbide, etc. are bonded together by a vitrified bond has been used (Patent Document 1).
  • the superabrasive grain according to one aspect of the present disclosure is A superabrasive grain comprising an abrasive grain body and an oxidation prevention film covering at least a part of the surface of the abrasive grain body,
  • the abrasive grain main body is made of cubic boron nitride or diamond,
  • the average grain size of the abrasive grain body is less than 1.0 ⁇ m.
  • a grindstone according to one aspect of the present disclosure a ring-shaped base metal, a superabrasive layer disposed on the surface of the base metal,
  • the superabrasive layer includes the superabrasive and a binder,
  • the softening point of the binder is 400°C or more and 1000°C or less.
  • FIG. 1 is a schematic cross-sectional view illustrating one embodiment of the superabrasive grain of the present disclosure.
  • FIG. 2 is a schematic cross-sectional view illustrating another embodiment of the superabrasive grain of the present disclosure.
  • FIG. 3 is a schematic plan view illustrating one embodiment of the grindstone of the present disclosure.
  • FIG. 4 is a cross-sectional view taken along the line IV--IV in FIG.
  • FIG. 5 is a schematic diagram showing a method of grinding a work material using a grindstone.
  • the manufacturing process of a grindstone that includes diamond or cubic boron nitride (cBN)-based abrasive grains and a binder includes a firing process in the atmosphere. Due to the firing process, the abrasive grains tend to be easily deteriorated by heat. In the case of abrasive grains made of diamond, the hardness of the diamond decreases due to a combustion reaction between the diamond and oxygen in the atmosphere. Further, due to the combustion reaction, the abrasive grains made of diamond themselves disappear, and the bonding strength at the interface between the abrasive grains and the binder decreases.
  • cBN cubic boron nitride
  • abrasive grains made of cBN the hardness of cBN decreases due to the reaction between cBN on the surface of the abrasive grains and oxygen to produce boron oxide. Therefore, the tool performance (sharpness) of a grindstone containing such abrasive grains may not be sufficient.
  • Thermal deterioration of abrasive grains as described above tends to occur particularly in ultrafine abrasive grains with a grain size of less than 1.0 ⁇ m, which are used under the processing conditions required to reduce the surface roughness of the machined surface.
  • an object of the present disclosure is to provide a superabrasive grain that can provide a whetstone with excellent grinding performance, and a whetstone that includes the superabrasive grain.
  • the abrasive grains according to one aspect of the present disclosure are: A superabrasive grain comprising an abrasive grain body portion and an oxidation prevention film covering at least a part of the surface of the abrasive grain body portion,
  • the abrasive grain main body is made of cubic boron nitride or diamond,
  • the average grain size of the abrasive grain main body portion is less than 1.0 ⁇ m.
  • a grindstone containing superabrasive grains according to one embodiment of the present disclosure can have excellent grinding performance.
  • thermogravimetric analysis is 70% or more,
  • the thermogravimetric analysis is preferably performed at a temperature of 900° C. and a holding time of 0.5 hours. This makes it possible to provide a grindstone with better grinding performance.
  • the antioxidant film is made of a first material,
  • the first material is made of ceramics or glass. This makes it possible to provide a grindstone with better grinding performance.
  • the superabrasive grains contain the first material in an amount of 0.1% by mass or more and less than 50% by mass. This makes it possible to provide a grindstone with better grinding performance.
  • the antioxidant film preferably covers 20% or more of the surface of the abrasive grain main body. This makes it possible to provide a grindstone with better grinding performance.
  • the grindstone of the present disclosure is a ring-shaped base metal, a superabrasive layer disposed on the surface of the base metal,
  • the superabrasive grain layer includes the superabrasive grains described in (1) to (5) above and a binder,
  • the softening point of the binder is 400°C or more and 1000°C or less. This makes it possible to provide a grindstone with excellent grinding performance.
  • the binder contains silicon, boron, and at least one element selected from the group consisting of alkali metal elements and alkaline earth metal elements,
  • the silicon content of the binder is 30% by mass or more and 70% by mass or less
  • the boron content of the bonding material is preferably 0% by mass or more and 30% by mass or less. This makes it possible to provide a grindstone with better grinding performance.
  • this embodiment An embodiment of the present disclosure (hereinafter referred to as “this embodiment”) will be described below. However, this embodiment is not limited to this.
  • the notation in the format "A to B” means the upper and lower limits of the range (i.e., from A to B), and when there is no unit described in A and only in B, The units of and the units of B are the same.
  • the superabrasive grain 10 is A superabrasive grain 10 comprising an abrasive grain main body part 1 and an oxidation prevention film 2 covering at least a part of the surface of the abrasive grain main body part 1,
  • the abrasive grain main body 1 is made of cubic boron nitride or diamond,
  • the average grain size of the abrasive main body portion 1 is less than 1.0 ⁇ m.
  • a grindstone containing superabrasive grains according to an embodiment of the present disclosure can have excellent grinding performance. The reason is presumed to be as follows.
  • the superabrasive grain 10 of the present disclosure at least a portion of the surface of the abrasive grain main body portion 1 is coated with an antioxidant film 2. Therefore, even in the firing process in the atmosphere when producing a grindstone using the superabrasive grains, the combustion reaction between the superabrasive grains and oxygen in the atmosphere can be suppressed. Therefore, it is presumed that the reduction in wear resistance caused by thermal deterioration and disappearance of the superabrasive grains can be suppressed, and the grinding performance of the grindstone is improved.
  • the superabrasive grains of the present disclosure do not require the addition of metals to lower the softening temperature of the binder during the manufacturing process of the grindstone, so the wear resistance of the grindstone due to elution of the metals into water is reduced. The decline can be prevented.
  • the grindstone containing the superabrasive grains according to this embodiment can have excellent grinding performance.
  • the abrasive grain main body portion according to this embodiment is made of cubic boron nitride or diamond.
  • cubic boron nitride or diamond is not limited to an embodiment consisting only of cubic boron nitride or diamond, but as long as the effects of the present disclosure are achieved, cubic boron nitride or diamond may be used together with cubic boron nitride or diamond.
  • This concept also includes embodiments containing components other than crystalline boron nitride and diamond (for example, unavoidable impurities).
  • unavoidable impurities in the abrasive grain body examples include carbon (C), aluminum (Al), silicon (Si), lithium (Li), calcium (Ca), and magnesium (Mg).
  • the content of unavoidable impurities in the abrasive grain body can be, for example, 0% or more and less than 1% on a mass basis.
  • the composition of the abrasive grain main body is determined by an energy dispersive X-ray analyzer (EDX) (Octane Elect Octane Elect) EDS System) (trademark).
  • EDX energy dispersive X-ray analyzer
  • the average grain size of the abrasive grain main body is less than 1.0 ⁇ m.
  • a grindstone including the abrasive grain main body has good sharpness, and the surface roughness of the machined surface can be made very small.
  • the average grain size of the abrasive grain body is 1.0 ⁇ m or more, the surface roughness of the machined surface tends to increase.
  • the lower limit of the average particle size of the abrasive grain main body is preferably 0.3 ⁇ m or more, more preferably 0.4 ⁇ m or more, and even more preferably 0.5 ⁇ m or more.
  • the upper limit of the average particle diameter of the abrasive grain main body is preferably 0.9 ⁇ m or less, more preferably 0.8 ⁇ m or less, and even more preferably 0.7 ⁇ m or less. Further, the average particle diameter of the abrasive grain main body is preferably 0.3 ⁇ m or more and 1.0 ⁇ m or less, more preferably 0.4 ⁇ m or more and 0.8 ⁇ m or less, and 0.5 ⁇ m or more and 0.7 ⁇ m or less. It is more preferable that
  • the average grain size of the abrasive grain main body can be specified by the following method. That is, after removing the antioxidant film by chemical treatment (the most suitable method is selected depending on the material), the volume-based D50 of the main body of the abrasive grain is measured using a particle size distribution meter.
  • the D50 is defined as the "average particle diameter of the abrasive grain main body". Note that the measurement method using the particle size distribution meter is the "laser diffraction method.”
  • the crystal structure of the abrasive grain main body can be single crystal or polycrystal.
  • the crystal structure of the abrasive grain body is single crystal, the strength of the abrasive grain body tends to improve.
  • the crystal structure of the abrasive grain main body is polycrystalline, the grinding ratio of a tool using an abrasive grain including the abrasive grain main body tends to be improved.
  • the crystal structure of the abrasive grain main body can be confirmed by X-ray diffraction.
  • the superabrasive according to this embodiment includes an oxidation-preventing film that covers at least a portion of the surface of the abrasive main body.
  • “coating at least a part of the surface of the abrasive grain body” means not only “coating the entire surface of the abrasive grain body” ( Figure 1), but also “covering the entire surface of the abrasive grain body” (Fig. 1). This concept also includes the case of "covering only a part of the surface” (FIG. 2).
  • the anti-oxidation film is preferably made of a first material described below.
  • “consisting of the first material” is not limited to an embodiment consisting only of the above first material, but as long as the effects of the present disclosure are achieved, components other than the above first material in addition to the above first material are used.
  • This concept also includes embodiments containing (for example, unavoidable impurities).
  • unavoidable impurities in the anti-oxidation film include C, Al, and Si.
  • the content of unavoidable impurities in the antioxidant film can be, for example, 0% or more and 1% or less on a mass basis.
  • the composition of the above-mentioned antioxidant film can be determined by ICP emission spectroscopy (high frequency inductively coupled plasma emission spectroscopy).
  • the first material is made of ceramic or glass.
  • thermal deterioration of the abrasive grains can be further suppressed in the production of whetstones, allowing the whetstone to have both superior sharpness and better abrasion resistance, resulting in better grinding performance. be able to.
  • the ceramics include one or more first elements selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements of the periodic table, aluminum (Al), and silicon (Si), and oxygen. , and at least one second element selected from the group consisting of nitrogen, carbon, and boron.
  • the first material is the above-mentioned ceramic
  • the oxidation-preventing film made of such a first material has excellent hardness and excellent wear resistance, so that the abrasive grain main body portion is not easily damaged.
  • the Group 4 elements of the periodic table are titanium (Ti), zirconium (Zr), and hafnium (Hf).
  • Group 5 elements of the periodic table are vanadium (V), niobium (Nb), and tantalum (Ta).
  • Group 6 elements of the periodic table are chromium (Cr), molybdenum (Mo), and tungsten (W).
  • Examples of compounds (oxides) consisting of the first element and oxygen include titanium oxide (TiO 2 ), zirconium oxide (ZrO 2 ), hafnium oxide (HfO 2 ), vanadium oxide (V 2 O 5 ), and niobium oxide. (Nb 2 O 5 ), tantalum oxide (Ta 2 O 5 ), chromium oxide (Cr 2 O 3 ), molybdenum oxide (MoO 3 ), tungsten oxide (WO 3 ), aluminum oxide (Al 2 O 3 ), silicon oxide (SiO 2 ) can be mentioned.
  • Examples of compounds (nitrides) consisting of the first element and nitrogen include titanium nitride (TiN), zirconium nitride (ZrN), hafnium nitride (HfN), vanadium nitride (VN), niobium nitride (NbN), and tantalum nitride.
  • TiN titanium tantalum nitride
  • TiCrN titanium chromium nitride
  • TiMoN titanium molybdenum nitride
  • TiWN titanium tungsten nitride
  • ZrHfN zirconium hafnium nitride
  • ZrVN zirconium vanadium nitride
  • ZrNbN zirconium niobium nitride
  • Examples of compounds (carbides) consisting of the first element and carbon include titanium carbide (TiC), zirconium carbide (ZrC), hafnium carbide (HfC), vanadium carbide (VC), niobium carbide (NbC), and tantalum carbide ( TaC), chromium carbide ( Cr2C ), molybdenum carbide (MoC), tungsten carbide (WC), titanium zirconium carbide (TiZrC), titanium hafnium carbide (TiHfC), titanium vanadium carbide (TiVC), titanium niobium carbide (TiNbC), Titanium tantalum carbide (TiTaC), titanium chromium carbide (TiCrC), titanium molybdenum carbide (TiMoC), titanium tungsten carbide (TiWC), zirconium hafnium carbide (ZrHfC), zirconium vanadium carbide (ZrVC), zirconium n
  • Examples of compounds (carbonitrides) consisting of the first element, carbon, and nitrogen include titanium carbonitride (TiCN), zirconium carbonitride (ZrCN), hafnium carbonitride (HfCN), aluminum carbonitride (AlCN), and carbonitride. Silicon nitride (SiCN) can be mentioned.
  • Examples of compounds (borides) consisting of the first element and boron include titanium boride (TiB 2 ), zirconium boride (ZrB 2 ), hafnium boride (HfB 2 ), vanadium boride (VB 2 ), Niobium boride (NbB 2 ), tantalum boride (TaB 2 ), chromium boride (CrB 2 ), molybdenum boride (MoB 2 ), tungsten boride (WB), aluminum boride (AlB 2 ), silicon boride (SiB 4 ) can be mentioned.
  • Examples of compounds (oxynitrides) consisting of the first element, nitrogen, and oxygen include titanium oxynitride (TiON), zirconium oxynitride (ZrON), hafnium oxynitride (HfON), vanadium oxynitride (VON), and Niobium nitride (NbON), tantalum oxynitride (TaON), chromium oxynitride (CrON), molybdenum oxynitride (MoON), tungsten oxynitride (WON), aluminum oxynitride (AlON), silicon oxynitride (SiON), Sialon ( SiAlON).
  • the above compounds may be used alone or in combination of two or more.
  • the first material can include a solid solution derived from the compound described above.
  • the solid solution derived from the above compound means a state in which two or more types of the above compounds are dissolved in each other's crystal structure, and means an interstitial solid solution or a substitutional solid solution.
  • the glass examples include borosilicate glass (glass containing SiO 2 , B 2 O 3 , Al 2 O 3 , Fe 2 O 3 , CaO, MgO, Na 2 O, and K 2 O).
  • borosilicate glass glass containing SiO 2 , B 2 O 3 , Al 2 O 3 , Fe 2 O 3 , CaO, MgO, Na 2 O, and K 2 O.
  • the superabrasive grains preferably contain the first material in an amount of 0.1% by mass or more and less than 50% by mass. As a result, thermal deterioration of the abrasive grains can be further suppressed in the production of the whetstone, so that the whetstone can have both excellent sharpness and better wear resistance.
  • the lower limit of the content of the first material in the superabrasive grains is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 10% by mass or more, from the viewpoint of suppressing thermal deterioration of the abrasive grains.
  • the upper limit of the content of the first material of the superabrasive grains is preferably 49% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less.
  • the content of the first material in the superabrasive grains is measured by the following procedure.
  • the superabrasive grains are subjected to ICP emission spectroscopy (high-frequency inductively coupled plasma emission spectroscopy).
  • the concentration of one element (group 4 element, group 5 element, group 6 element of the periodic table, aluminum (Al), and silicon (Si)) is measured.
  • the concentration of the compound (oxide, carbide, nitride, carbonitride, or boride) of the first element is converted to calculate the mass of the compound of the first element.
  • the first material is glass
  • elements other than oxygen for example, silicon ( Measure the concentrations of Si), boron (B), aluminum (Al), iron (Fe), calcium (Ca), magnesium (Mg), sodium (Na), and potassium (K)).
  • Si silicon
  • B aluminum
  • Fe iron
  • Ca calcium
  • Mg magnesium
  • Na sodium
  • K potassium
  • the antioxidant film preferably covers 20% or more of the surface of the abrasive grain body. As a result, thermal deterioration of the abrasive grains can be further suppressed in the production of whetstones, allowing the whetstone to have both superior sharpness and better abrasion resistance, resulting in better grinding performance. be able to.
  • the antioxidant film more preferably covers 50% or more of the surface of the abrasive grain main body, and still more preferably covers 70% or more. Moreover, it is more preferable that the antioxidant film covers 100% of the surface of the abrasive grain main body. From a manufacturing standpoint, the antioxidant film can cover 99% or less, 98% or less, or 97% or less of the surface of the abrasive grain main body. Further, the antioxidant film preferably covers 20% or more and 100% or less of the surface of the abrasive grain body, more preferably 50% or more and 100% or less, and 70% or more and 100% or less. More preferably, it is coated.
  • the proportion of the surface of the abrasive grain body covered with the antioxidant film can be determined by the following method.
  • (a1) Observe at a magnification of 5,000 to 200,000 times using a scanning electron microscope (SEM) equipped with energy dispersive X-ray analysis (EDS) to obtain a backscattered electron image of the superabrasive grain.
  • a measurement area is set in the backscattered electron image. The measurement area is set so that 100 or more superabrasive grains are included in the measurement area.
  • (c1) In the measurement region, identify the antioxidant film by mapping and analyzing the constituent elements of the first material using EDS, and measure the area A2 occupied by the antioxidant film in the measurement region (as shown in the figure). none).
  • the constituent elements of the first material on which the mapping analysis is performed are elements other than carbon, boron, and nitrogen.
  • the residual rate of the superabrasive grains in thermogravimetric analysis is preferably 70% or more.
  • the thermogravimetric analysis is performed under conditions of a temperature of 900° C. and a holding time of 0.5 hours. This makes it possible to further suppress thermal deterioration of the superabrasive grains in the production of grinding wheels, allowing the grinding wheels to have both superior sharpness and better wear resistance, resulting in better grinding performance. can be done.
  • the lower limit of the residual rate in thermogravimetric analysis of the superabrasive grains is more preferably 80% or more, and even more preferably 90% or more.
  • the upper limit of the residual rate in thermogravimetric analysis of the superabrasive grains is preferably 100% or less.
  • the residual rate of the superabrasive grains in thermogravimetric analysis can be set to 99.5% or less, 99.0% or less, or 98.5% or less from the viewpoint of manufacturing.
  • the residual rate of the superabrasive grains in thermogravimetric analysis is preferably 70% or more and 100% or less, more preferably 80% or more and 100% or less, and even more preferably 90% or more and 100% or less. .
  • the residual rate of the superabrasive in thermogravimetric analysis can be determined by performing the following thermogravimetric analysis on the superabrasive at a temperature of 900° C. and a holding time of 0.5 hours.
  • 30 mg (initial weight) of superabrasive grains is prepared and applied to a thermogravimetric (TG) meter (the TG meter can measure the weight change of a substance during heating in real time).
  • TG thermogravimetric
  • the temperature is raised from room temperature to 900°C at a heating rate of 10°C/min, and then 900°C is maintained for 30 minutes.
  • the atmosphere is atmospheric.
  • the remaining weight at this time is measured.
  • the method for producing superabrasive grains includes a step of preparing an abrasive grain main body made of cubic boron nitride or diamond (hereinafter also referred to as a "preparation step"), and a step of preparing an abrasive grain main body made of cubic boron nitride or diamond, and oxidizing the surface of the abrasive grain main body.
  • the method may include a step of forming a preventive film (hereinafter also referred to as a "coating step").
  • Cubic boron nitride or diamond which is the raw material for the abrasive grain body, is prepared.
  • Cubic boron nitride and diamond are not particularly limited, and known ones can be used.
  • Pretreatment can be performed on the prepared abrasive grain main body made of cubic boron nitride or diamond. Pretreatment includes heat treatment, electron beam irradiation, plasma irradiation, and microwave irradiation.
  • an anti-oxidation film is formed on the surface of the prepared abrasive grain main body.
  • the anti-oxidation film can be formed by the sol-gel method, by using crushed ceramics or crushed glass as a binder and adsorbing it to the abrasive grain body, or by electrostatically adsorbing crushed ceramics or crushed glass to the abrasive grain body. method, chemical vapor deposition, or sputtering using a target material.
  • sol-gel method When the first material is made of glass, a sol-gel method can be applied.
  • the main body of the abrasive grain is mixed with an alkoxide such as tetraethoxysilane.
  • an alkoxide such as tetraethoxysilane.
  • the alkoxide is hydrolyzed and polycondensed, thereby coating the main body of the abrasive grain with a sol. This is dried to form a gel, and then sintered at an appropriate temperature to turn the gel into glass and form an antioxidant film.
  • the ceramic or glass used is one that has been crushed in advance.
  • the abrasive grain body and ceramic or glass are uniformly mixed in a solvent (eg, water, alcohol, etc.) by a method such as a bead mill.
  • a solvent eg, water, alcohol, etc.
  • the mixing ratio of the abrasive grain main body and ceramic or glass is adjusted to obtain the desired grain size and coverage.
  • an organic binder such as polyvinyl alcohol (PVA). Selection of the appropriate binder type varies depending on the type of solvent mentioned above) is added, and the organic binder and the ceramic or glass are combined with the abrasive grains. Adsorb it to the main body.
  • the first material consists of a ceramic or an oxide
  • chemical vapor deposition methods can be used.
  • the abrasive grain main body is placed in a reaction tube.
  • a compound that easily vaporizes usually a halide, hydride, organometallic compound, etc.
  • a chemical reaction reaction/thermal decomposition. etc.
  • the reaction may require high temperatures depending on the substance being vaporized, but low temperature coatings are also possible using plasma chemical vapor deposition.
  • the first material is made of ceramics
  • the following conditions may be mentioned as the coating conditions.
  • an oxidation-preventing film made of ceramics (first material) can be formed on the surface of the abrasive grain main body.
  • Target material aluminum (metal)
  • Atmosphere Vacuum Discharge voltage: 125V or more and 250V or less
  • the grindstone 20 according to an embodiment of the present disclosure will be described using FIGS. 3 and 4.
  • the grindstone 20 according to this embodiment is a ring-shaped base metal 120; a superabrasive layer 12 disposed on the surface of the base metal 120;
  • the superabrasive grain layer 12 includes the superabrasive grains 10 according to the first embodiment and a bonding material 11,
  • the softening point of the bonding material 11 is 400°C or more and 1000°C or less.
  • the grindstone 20 according to an embodiment of the present disclosure can have excellent grinding performance.
  • the reason is presumed to be as follows.
  • the grindstone 20 of the present disclosure includes an annular base metal 120 and a superabrasive grain layer 12 disposed on the surface of the base metal 120. More specifically, as shown in FIGS. 3 and 4, the grinding wheel 20 includes a cup-shaped base metal 120 and a cup-shaped base metal 120, and a pair of metal parts spaced apart from each other along the circumferential direction on one end surface 121 (use surface) of the base metal 120. It is composed of a plurality of flat plate-shaped superabrasive grain layers 12 that are spaced apart and fixed.
  • Each superabrasive layer 12 is attached to the base metal 120 so that the circumferential end surface 111 of the superabrasive layer 12 is substantially parallel to the rotation axis of the grinding wheel 20, and the length direction of the superabrasive layer 12 is in the radial direction of the grinding wheel 20. It is fixed to one end surface 121 (use surface) of.
  • Each superabrasive layer 12 has a working surface 112 substantially perpendicular to the axis of rotation of the grinding wheel 20.
  • the superabrasive grain layer 12 includes the superabrasive grains 10 according to the present embodiment 1, and the superabrasive grains 10 according to the present embodiment 1 cover at least one surface of the abrasive grain main body 1, as described above. portion is coated with an anti-oxidation film 2. Therefore, even in the firing process in the atmosphere when manufacturing the grindstone 20 using the superabrasive grains 10, the combustion reaction between the superabrasive grains 10 and oxygen in the atmosphere can be suppressed. Therefore, it is presumed that the decrease in wear resistance caused by thermal deterioration and disappearance of the superabrasive grains 10 can be suppressed, and the grinding performance of the grindstone 20 is improved.
  • the superabrasive grain 10 of the present disclosure does not require the addition of metals to lower the softening temperature of the bonding material 11 in the manufacturing process of the grinding wheel 20, the grinding wheel 20 may be reduced due to elution of the metals into water. Decrease in wear resistance can be prevented.
  • the superabrasive layer 12 includes a binder 11, and the softening point of the binder 11 is 400°C or more and 1000°C or less. Since such a bonding material has excellent mechanical strength, the grindstone 20 can have excellent grinding performance.
  • the grindstone 20 according to this embodiment can have excellent grinding performance.
  • Examples of the material of the base metal include Al, Al alloy, iron and iron alloy, carbon tool steel, high speed tool steel, alloy tool steel, cemented carbide, and cermet.
  • the size of the base metal (inner/outer diameter, thickness) can be appropriately selected depending on, for example, the size of a machine tool such as a machining center in which the grindstone is installed, that is, the size of the workpiece.
  • a base metal of a known grindstone can be used as the base metal.
  • Superabrasive layer 12 is disposed on the surface of base metal 120 (FIG. 4).
  • the size (thickness and width) of the superabrasive grain layer 12 can be appropriately selected depending on the size (thickness and width) of the base metal 120.
  • the thickness refers to the length of the grindstone 20 along the radial direction, and the width refers to the length of the grindstone 20 along the axial direction.
  • the superabrasive layer according to this embodiment includes the superabrasive and the bonding material.
  • the above-mentioned grindstone can be made of the above-mentioned superabrasive grains and the above-mentioned bonding material. Further, the superabrasive layer may include pores as long as it exhibits the effects of the present disclosure. In the grindstone, the content of the pores may be 40% by volume or more and 95% by volume or less.
  • the lower limit of the content of the superabrasive is preferably 10% by volume or more, 15% by volume or more, or 20% by volume or more.
  • the upper limit of the content of the superabrasive is preferably 60% by volume or less, 50% by volume or less, and 40% by volume or less.
  • the content of the superabrasive grains is preferably 10 vol% or more and 60 vol% or less, 15 vol% or more and 50 vol% or less, and 20 vol% or more and 40 vol% or less.
  • the content of super-abrasive grains is determined by separating the abrasive grains and binder from a 1 cm3 piece of the cutting edge of the abrasive stone by chemical treatment, measuring the weight of the abrasive grains, and measuring the weight of the abrasive grains.
  • the volume is determined by dividing by the density (g/cm 3 ). Since this is the volume (cm 3 ) contained in 1 cm 3 , it can be specified by multiplying the numerical value of the volume by 100.
  • the "superabrasive content" has been measured multiple times by arbitrarily setting the cutting point of the grinding wheel edge and following the above procedure. It was also confirmed that there was little variation in the measurement results, and that even if the cutting point of the grindstone edge was set arbitrarily, it would not be arbitrary.
  • the lower limit of the content of the binder is preferably 1% by volume or more, 2% by volume or more, or 3% by volume or more.
  • the upper limit of the content of the binder is preferably 30% by volume or less, 20% by volume or less, and 10% by volume or less.
  • the content of the binder is preferably 1 volume % or more and 30 volume % or less, 2 volume % or more and 20 volume % or less, and 3 volume % or more and 10 volume % or less.
  • the content of the binder is determined by separating the abrasive grains and the binder from a 1cm3 piece of the cutting edge of the grinding wheel by chemical treatment, measuring the weight of the binder, and determining the content of the binder.
  • the volume is determined by dividing by the density (g/cm 3 ). Since this is the volume (cm 3 ) contained in 1 cm 3 , it can be specified by multiplying the numerical value of the volume by 100.
  • the superabrasive grain of Embodiment 1 is used.
  • the number of superabrasive grains can be plural.
  • a portion of the superabrasive grains 10 on the surface side of the superabrasive grain layer 12 is exposed from the bonding material 11, and the exposed portion has a cutting edge portion for grinding the work material.
  • all of the superabrasive grains 10 on the base metal 120 side of the superabrasive grain layer 12 are embedded in the bonding material 11.
  • the buried superabrasive grains 10 are removed during grinding of a workpiece with the grindstone 20, in the process in which the superabrasive grains 10 on the surface side of the superabrasive grain layer 12 wear out and fall off, and the bonding material 11 wears out. The part is exposed from the bonding material 11 and the workpiece is ground (FIG. 4).
  • All of the plurality of superabrasive grains may be composed of an abrasive grain body portion having the same configuration (material and size) and an oxidation prevention film having the same configuration (material and thickness). Further, the abrasive grain main body portion and oxidation prevention film of some superabrasive grains may have a different configuration (material and size) from the abrasive grain main body portion and oxidation prevention film of other portions of the superabrasive grain. Moreover, known abrasive grains other than superabrasive grains may be mixed in the superabrasive grain layer.
  • the bonding material 11 fixes the superabrasive grains 10 to one end surface 121 (usable surface) of the base metal 120 (FIG. 4).
  • Examples of the type of bonding material include one type of bond selected from vitrified bond, metal bond, and a composite bond of these, or metal solder. As these bonds and metal solders, known bonds and metal solders can be used.
  • vitrified bond is that the main component is glass.
  • metal bonds include copper-tin alloys.
  • metal solder include silver (Ag) solder.
  • the type of bonding material can be selected as appropriate depending on the material of the anti-oxidation film of the superabrasive grains.
  • the bonding material can be, for example, vitrified bond, metal bond, or metal solder.
  • the binder is preferably vitrified bond.
  • the softening point of the binder is 400°C or more and 1000°C or less. Since such a binding material has excellent mechanical strength, the grindstone can have excellent grinding performance.
  • the lower limit of the softening point of the binder is preferably 500°C or higher, more preferably 600°C or higher, and even more preferably 700°C or higher.
  • the upper limit of the softening point of the binder is preferably 950°C or lower, more preferably 900°C or lower, and even more preferably 850°C or lower.
  • the softening point of the binder is preferably 500°C or more and 950°C or less, more preferably 600°C or more and 900°C or less, and even more preferably 700°C or more and 850°C or less.
  • the above-mentioned softening point can be determined by extrapolating a straight line from two points where the curvature of the expansion curve characteristically changes when thermal expansion is measured in compression mode measurement using thermomechanical measurement (TMA), and finding it from the intersection of these points. .
  • TMA thermomechanical measurement
  • the binder contains silicon, boron, and at least one element selected from the group consisting of alkali metal elements and alkaline earth metal elements, and the silicon content of the binder is 30% by mass or more. It is preferably 70% by mass or less, and the boron content of the bonding material is preferably 0% by mass or more and 30% by mass or less. This further increases the affinity between the superabrasive grains provided with the oxidation-preventing film and the binder via the oxidation-preventing film. As a result, the grindstone can have better grinding performance.
  • the alkali metal elements include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr).
  • examples of alkaline earth metal elements include calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).
  • the silicon content of the bonding material is more preferably 40% by mass or more, and even more preferably 50% by mass or more.
  • the silicon content of the bonding material is more preferably 60% by mass or less, and even more preferably 55% by mass or less.
  • the silicon content of the bonding material is more preferably 40% by mass or more and 60% by mass or less, and even more preferably 50% by mass or more and 55% by mass or less.
  • the boron content of the bonding material is more preferably 5% by mass or more, and even more preferably 10% by mass or more.
  • the boron content of the bonding material is more preferably 25% by mass or less, and even more preferably 20% by mass or less.
  • the boron content of the bonding material is more preferably 5% by mass or more and 25% by mass or less, and even more preferably 10% by mass or more and 20% by mass or less.
  • the composition of the binder can be identified by ICP emission spectroscopy (high frequency inductively coupled plasma emission spectroscopy).
  • the grinding wheel 20 (FIGS. 3 and 4) is prepared by preparing a plurality of superabrasive grains 10 (FIGS. 1 and 2) in which at least a portion of the surface of the abrasive grain main body 1 is coated with an anti-oxidation film 2, and applying a bonding material. 11, by fixing a plurality of superabrasive grains 10 to one end surface 121 (usable surface) of the base metal 120 (FIG. 4).
  • the grinding wheel 20 is prepared by preparing a plurality of abrasive grain main bodies 1 that are not coated with the anti-oxidation film 2, and bonding the plurality of abrasive grain main body parts 1 to one end surface 121 (usable surface) of the base metal 120 using a bonding material 11. After the abrasive particles are fixed, the anti-oxidation film 2 may be formed to cover the surface (cutting edge portion) of the abrasive grain body 1.
  • coating methods include the above-mentioned sol-gel method, a method in which crushed ceramics or crushed glass is adsorbed onto the abrasive grain body using a binder, and a method in which crushed ceramics or crushed glass is electrostatically applied to the abrasive grain body. Any of an adsorption method, a chemical vapor deposition method, and a sputtering method using a target material can be used.
  • the grindstone according to the embodiment can be suitably used for grinding automobile parts, optical glass, magnetic materials, semiconductor materials, etc., groove grinding of end mills, drills, reamers, etc., breaker grinding of indexable tips, and heavy grinding of various tools. .
  • thermogravimetric analysis residual rate [%] the residual ratio in thermogravimetric analysis of the superabrasive grains was determined by the method described in Embodiment 1. The obtained results are recorded in the "thermogravimetric analysis residual rate [%]" column in the "superabrasive” column of Tables 4 and 5.
  • the workpiece 130 is fixed on the table 110.
  • the table 110 is rotatable in the direction indicated by an arrow 110R.
  • the grindstone 20 is rotatable in the direction indicated by the arrow 1R.
  • the direction indicated by arrow 1F is the cutting direction.
  • the above samples 1 to 3, 9, 11 to 17, and 20 to 42 correspond to examples, and the above samples 4 to 6, 10, 18, and 19 correspond to comparative examples.
  • the grinding wheels of Samples 1 to 3, 9, 11 to 17, and 20 to 42 exhibited exceptionally high grinding ratios compared to the grinding wheels of Samples 4 to 6, 10, 18, and 19. Comparing samples with the same average particle diameter of the abrasive grain body, the grinding wheels of samples 1 to 3, 9, 11 to 17, and 20 to 42 are superior to those of samples 4 to 6, 10, 18, and 19. In comparison, it has exceptionally excellent sharpness and exceptionally excellent wear resistance. That is, the grindstones of Samples 1 to 3, 9, 11 to 17, and 20 to 42 have exceptionally excellent grinding performance compared to the grindstones of Samples 4 to 6, 10, 18, and 19.

Abstract

This superabrasive grain comprises an abrasive grain body section and an antioxidant film that coats at least a portion of the surface of the abrasive grain body section, wherein the abrasive grain body section comprises cubic boron nitride or diamond and the average particle diameter of the abrasive grain body section is less than 1.0 µm.

Description

超砥粒および砥石Superabrasives and grinding wheels
　本開示は、超砥粒および砥石に関する。 The present disclosure relates to superabrasives and grindstones.
　精密加工に用いられる工具として、砥粒と結合材とを含む砥石が用いられる。従来より、ダイヤモンド、立方晶窒化硼素、アルミナ、炭化珪素などからなる砥粒をビトリファイドボンドによって結合した砥石が用いられている（特許文献１）。 A grindstone containing abrasive grains and a binder is used as a tool for precision machining. BACKGROUND ART Conventionally, a grindstone in which abrasive grains made of diamond, cubic boron nitride, alumina, silicon carbide, etc. are bonded together by a vitrified bond has been used (Patent Document 1).
特開２０１４－１２３２８号公報JP2014-12328A
　本開示の一態様に係る超砥粒は、
　砥粒本体部と、該砥粒本体部の表面の少なくとも一部を被覆する酸化防止膜とを備える、超砥粒であって、
　該砥粒本体部は、立方晶窒化硼素又はダイヤモンドからなり、
　該砥粒本体部の平均粒径は、１．０μｍ未満である。 The superabrasive grain according to one aspect of the present disclosure is
A superabrasive grain comprising an abrasive grain body and an oxidation prevention film covering at least a part of the surface of the abrasive grain body,
The abrasive grain main body is made of cubic boron nitride or diamond,
The average grain size of the abrasive grain body is less than 1.0 μm.
　本開示の一態様に係る砥石は、
　環状の台金と、
　該台金の表面上に配置された超砥粒層と、を備え、
　該超砥粒層は、上記超砥粒と、結合材とを含み、
　該結合材の軟化点は、４００℃以上１０００℃以下である。 A grindstone according to one aspect of the present disclosure,
a ring-shaped base metal,
a superabrasive layer disposed on the surface of the base metal,
The superabrasive layer includes the superabrasive and a binder,
The softening point of the binder is 400°C or more and 1000°C or less.
図１は、本開示の超砥粒の一態様を例示する模式断面図である。FIG. 1 is a schematic cross-sectional view illustrating one embodiment of the superabrasive grain of the present disclosure. 図２は、本開示の超砥粒の他の態様を例示する模式断面図である。FIG. 2 is a schematic cross-sectional view illustrating another embodiment of the superabrasive grain of the present disclosure. 図３は、本開示の砥石の一態様を例示する模式平面図である。FIG. 3 is a schematic plan view illustrating one embodiment of the grindstone of the present disclosure. 図４は、図３のＩＶ－ＩＶ線断面図である。FIG. 4 is a cross-sectional view taken along the line IV--IV in FIG. 図５は、砥石により被削材を研削加工する方式を示す模式図である。FIG. 5 is a schematic diagram showing a method of grinding a work material using a grindstone.
［本開示が解決しようとする課題］
　ダイヤモンドや立方晶窒化硼素（ｃＢＮ）をベースとする砥粒と、結合材とを含む砥石の製造工程は、大気下での焼成工程を含む。該焼成工程により、砥粒が熱劣化し易い傾向がある。ダイヤモンドからなる砥粒の場合、ダイヤモンドが大気中の酸素と燃焼反応を生じることによって、ダイヤモンドの硬度が低下する。また、燃焼反応により、ダイヤモンドからなる砥粒自体が消失して、砥粒と結合材との界面の接合強度が低下する。ｃＢＮからなる砥粒の場合、砥粒表面のｃＢＮと酸素とが反応して酸化硼素を生じることに起因して、ｃＢＮの硬度は低下する。その為、そのような砥粒を含む砥石の工具性能（切れ味）は十分でない場合があった。上記のような砥粒の熱劣化は、特に加工面の表面粗さを小さくする為に必要な加工条件に用いられる粒径が１．０μｍ未満の超微粒の砥粒において生じやすい傾向がある。 [Problems that this disclosure seeks to solve]
The manufacturing process of a grindstone that includes diamond or cubic boron nitride (cBN)-based abrasive grains and a binder includes a firing process in the atmosphere. Due to the firing process, the abrasive grains tend to be easily deteriorated by heat. In the case of abrasive grains made of diamond, the hardness of the diamond decreases due to a combustion reaction between the diamond and oxygen in the atmosphere. Further, due to the combustion reaction, the abrasive grains made of diamond themselves disappear, and the bonding strength at the interface between the abrasive grains and the binder decreases. In the case of abrasive grains made of cBN, the hardness of cBN decreases due to the reaction between cBN on the surface of the abrasive grains and oxygen to produce boron oxide. Therefore, the tool performance (sharpness) of a grindstone containing such abrasive grains may not be sufficient. Thermal deterioration of abrasive grains as described above tends to occur particularly in ultrafine abrasive grains with a grain size of less than 1.0 μm, which are used under the processing conditions required to reduce the surface roughness of the machined surface.
　このような砥粒の熱劣化を抑制する手段として、砥石の結合材であるガラスに金属類を添加することにより、結合材（ガラス）の軟化温度を下げることが考えられる。しかしながら、このような手段は、実用上望ましくない結果を招くことがある。このような金属類の多くは砥石の結合材（ガラス）の化学的安定性を低下させる為、該金属類が水に溶出し易くなる。その結果、該金属類の水への溶出によって、砥石の強度が低下する場合があった。また、そのような金属類が添加された砥石は、使用に伴って強度を低下し易い為、該砥石の研削性能（耐摩耗性）が低下する場合があった。その為、切れ味と耐摩耗性とに優れ、優れた研削性能を有する砥石が求められている。 As a means of suppressing such thermal deterioration of the abrasive grains, it is conceivable to lower the softening temperature of the bonding material (glass) by adding metals to the glass, which is the bonding material of the grindstone. However, such measures may lead to practically undesirable results. Many of these metals reduce the chemical stability of the bonding material (glass) of the grindstone, making them more likely to dissolve into water. As a result, the strength of the grindstone may be reduced due to elution of the metals into water. In addition, since a grindstone to which such metals are added tends to decrease in strength with use, the grinding performance (wear resistance) of the grindstone may deteriorate. Therefore, there is a need for a grindstone that has excellent sharpness, wear resistance, and excellent grinding performance.
　そこで、本開示は、砥石に優れた研削性能を備えさせることが可能な超砥粒、および該超砥粒を含む砥石を提供することを目的とする。
［本開示の効果］ Therefore, an object of the present disclosure is to provide a superabrasive grain that can provide a whetstone with excellent grinding performance, and a whetstone that includes the superabrasive grain.
[Effects of this disclosure]
　本開示によれば、砥石に優れた研削性能を備えさせることが可能な超砥粒、及びそれを含む砥石を提供することができる。 According to the present disclosure, it is possible to provide superabrasive grains that can provide a whetstone with excellent grinding performance, and a whetstone that includes the superabrasive grains.
　［本開示の実施形態の説明］
　最初に本開示の実施態様を列記して説明する。
　（１）本開示の一態様に係る砥粒は、
　砥粒本体部と、前記砥粒本体部の表面の少なくとも一部を被覆する酸化防止膜とを備える、超砥粒であって、
　前記砥粒本体部は、立方晶窒化硼素又はダイヤモンドからなり、
　前記砥粒本体部の平均粒径は、１．０μｍ未満である。 [Description of embodiments of the present disclosure]
First, embodiments of the present disclosure will be listed and described.
(1) The abrasive grains according to one aspect of the present disclosure are:
A superabrasive grain comprising an abrasive grain body portion and an oxidation prevention film covering at least a part of the surface of the abrasive grain body portion,
The abrasive grain main body is made of cubic boron nitride or diamond,
The average grain size of the abrasive grain main body portion is less than 1.0 μm.
　本開示の一態様に係る超砥粒を含む砥石は、優れた研削性能を有することができる。 A grindstone containing superabrasive grains according to one embodiment of the present disclosure can have excellent grinding performance.
　（２）上記（１）において、前記超砥粒の熱重量分析における残存率は、７０％以上であり、
　前記熱重量分析は、温度９００℃かつ保持時間０．５時間の条件下で実行されることが好ましい。これによって、より優れた研削性能を有する砥石を提供することができる。 (2) In (1) above, the residual rate of the superabrasive grains in thermogravimetric analysis is 70% or more,
The thermogravimetric analysis is preferably performed at a temperature of 900° C. and a holding time of 0.5 hours. This makes it possible to provide a grindstone with better grinding performance.
　（３）上記（１）または（２）において、前記酸化防止膜は、第１材料からなり、
　前記第１材料は、セラミックスまたはガラスからなることが好ましい。これによって、より優れた研削性能を有する砥石を提供することができる。 (3) In (1) or (2) above, the antioxidant film is made of a first material,
Preferably, the first material is made of ceramics or glass. This makes it possible to provide a grindstone with better grinding performance.
　（４）上記（３）において、前記超砥粒は、前記第１材料を０．１質量％以上５０質量％未満で含むことが好ましい。これによって、より優れた研削性能を有する砥石を提供することができる。 (4) In (3) above, it is preferable that the superabrasive grains contain the first material in an amount of 0.1% by mass or more and less than 50% by mass. This makes it possible to provide a grindstone with better grinding performance.
　（５）上記（１）から（４）のいずれかにおいて、前記酸化防止膜は、前記砥粒本体部の表面の２０％以上を被覆することが好ましい。これによって、より優れた研削性能を有する砥石を提供することができる。 (5) In any one of (1) to (4) above, the antioxidant film preferably covers 20% or more of the surface of the abrasive grain main body. This makes it possible to provide a grindstone with better grinding performance.
　（６）本開示の砥石は、
　環状の台金と、
　前記台金の表面上に配置された超砥粒層と、を備え、
　前記超砥粒層は、上述の（１）から（５）に記載の超砥粒と、結合材とを含み、
　前記結合材の軟化点は、４００℃以上１０００℃以下である。これによって、優れた研削性能を有する砥石を提供することができる。 (6) The grindstone of the present disclosure is
a ring-shaped base metal,
a superabrasive layer disposed on the surface of the base metal,
The superabrasive grain layer includes the superabrasive grains described in (1) to (5) above and a binder,
The softening point of the binder is 400°C or more and 1000°C or less. This makes it possible to provide a grindstone with excellent grinding performance.
　（７）上記（６）において、前記結合材は、珪素と、硼素と、アルカリ金属元素およびアルカリ土類金属元素からなる群より選択される少なくとも１種の元素とを含み、
　前記結合材の珪素の含有率は、３０質量％以上７０質量％以下であり、
　前記結合材の硼素の含有率は、０質量％以上３０質量％以下であることが好ましい。これによって、より優れた研削性能を有する砥石を提供することができる。 (7) In (6) above, the binder contains silicon, boron, and at least one element selected from the group consisting of alkali metal elements and alkaline earth metal elements,
The silicon content of the binder is 30% by mass or more and 70% by mass or less,
The boron content of the bonding material is preferably 0% by mass or more and 30% by mass or less. This makes it possible to provide a grindstone with better grinding performance.
　［本開示の実施形態の詳細］
　以下、本開示の一実施形態（以下「本実施形態」と記す。）について説明する。ただし、本実施形態はこれに限定されるものではない。本明細書において「Ａ～Ｂ」という形式の表記は、範囲の上限下限（すなわちＡ以上Ｂ以下）を意味し、Ａにおいて単位の記載がなく、Ｂにおいてのみ単位が記載されている場合、Ａの単位とＢの単位とは同じである。 [Details of embodiments of the present disclosure]
An embodiment of the present disclosure (hereinafter referred to as "this embodiment") will be described below. However, this embodiment is not limited to this. In this specification, the notation in the format "A to B" means the upper and lower limits of the range (i.e., from A to B), and when there is no unit described in A and only in B, The units of and the units of B are the same.
　［実施形態１：超砥粒］
　本開示の一実施形態に係る超砥粒について、図１および図２を用いて説明する。
　本開示の一実施形態（以下、「本実施形態」とも記す。）に係る超砥粒１０は、
　砥粒本体部１と、該砥粒本体部１の表面の少なくとも一部を被覆する酸化防止膜２とを備える、超砥粒１０であって、
　該砥粒本体部１は、立方晶窒化硼素又はダイヤモンドからなり、
　該砥粒本体部１の平均粒径は、１．０μｍ未満である。 [Embodiment 1: Super abrasive]
A superabrasive grain according to an embodiment of the present disclosure will be described using FIGS. 1 and 2.
The superabrasive grain 10 according to an embodiment of the present disclosure (hereinafter also referred to as "this embodiment") is
A superabrasive grain 10 comprising an abrasive grain main body part 1 and an oxidation prevention film 2 covering at least a part of the surface of the abrasive grain main body part 1,
The abrasive grain main body 1 is made of cubic boron nitride or diamond,
The average grain size of the abrasive main body portion 1 is less than 1.0 μm.
　本開示の一実施形態に係る超砥粒を含む砥石は、優れた研削性能を有することが可能である。その理由は、以下の通りと推察される。 A grindstone containing superabrasive grains according to an embodiment of the present disclosure can have excellent grinding performance. The reason is presumed to be as follows.
　本開示の超砥粒１０では、該砥粒本体部１の表面の少なくとも一部が酸化防止膜２で被覆されている。このため、該超砥粒を用いた砥石を製造する際の大気中での焼成工程においても、該超砥粒と大気中の酸素との燃焼反応を抑制できる。よって、該超砥粒の熱劣化及び消失に起因する耐摩耗性の低下を抑制でき、砥石の研削性能が向上すると推察される。 In the superabrasive grain 10 of the present disclosure, at least a portion of the surface of the abrasive grain main body portion 1 is coated with an antioxidant film 2. Therefore, even in the firing process in the atmosphere when producing a grindstone using the superabrasive grains, the combustion reaction between the superabrasive grains and oxygen in the atmosphere can be suppressed. Therefore, it is presumed that the reduction in wear resistance caused by thermal deterioration and disappearance of the superabrasive grains can be suppressed, and the grinding performance of the grindstone is improved.
　また、本開示の超砥粒は、砥石の製造工程において結合材の軟化温度を下げるための金属類の添加を要しない為、該金属類の水への溶出に起因する砥石の耐摩耗性の低下を防ぐことができる。 In addition, the superabrasive grains of the present disclosure do not require the addition of metals to lower the softening temperature of the binder during the manufacturing process of the grindstone, so the wear resistance of the grindstone due to elution of the metals into water is reduced. The decline can be prevented.
　よって、本実施形態に係る超砥粒を含む砥石は、優れた研削性能を有することができる。 Therefore, the grindstone containing the superabrasive grains according to this embodiment can have excellent grinding performance.
　≪砥粒本体部≫
　＜砥粒本体部の組成＞
　本実施形態に係る砥粒本体部は、立方晶窒化硼素又はダイヤモンドからなる。ここで、「立方晶窒化硼素又はダイヤモンドからなる」とは、立方晶窒化硼素又はダイヤモンドのみからなる態様に限られず、本開示の効果が奏される限りにおいて、立方晶窒化硼素又はダイヤモンドとともに、立方晶窒化硼素およびダイヤモンド以外の成分（例えば、不可避不純物）を含む態様をも包含する概念である。上記砥粒本体部の不可避不純物としては、例えば炭素（Ｃ）、アルミニウム（Ａｌ）、珪素（Ｓｉ）、リチウム（Ｌｉ）、カルシウム（Ｃａ）、マグネシウム（Ｍｇ）が挙げられる。砥粒本体部中の不可避不純物の含有率は、例えば、質量基準で、０％以上１％未満とすることができる。 ≪Abrasive grain body≫
<Composition of the abrasive grain body>
The abrasive grain main body portion according to this embodiment is made of cubic boron nitride or diamond. Here, "consisting of cubic boron nitride or diamond" is not limited to an embodiment consisting only of cubic boron nitride or diamond, but as long as the effects of the present disclosure are achieved, cubic boron nitride or diamond may be used together with cubic boron nitride or diamond. This concept also includes embodiments containing components other than crystalline boron nitride and diamond (for example, unavoidable impurities). Examples of unavoidable impurities in the abrasive grain body include carbon (C), aluminum (Al), silicon (Si), lithium (Li), calcium (Ca), and magnesium (Mg). The content of unavoidable impurities in the abrasive grain body can be, for example, 0% or more and less than 1% on a mass basis.
　超砥粒において、砥粒本体部の組成は、走査電子顕微鏡（ＳＥＭ）（日本電子社製の「ＪＳＭ－７８００Ｆ」（商標））付帯のエネルギー分散型Ｘ線分析装置（ＥＤＸ）（Ｏｃｔａｎｅ　Ｅｌｅｃｔ（オクタンエレクト）ＥＤＳ　システム）（商標）により特定することができる。 In superabrasive grains, the composition of the abrasive grain main body is determined by an energy dispersive X-ray analyzer (EDX) (Octane Elect Octane Elect) EDS System) (trademark).
　＜砥粒本体部の平均粒径＞
　上記砥粒本体部の平均粒径は、１．０μｍ未満である。該砥粒本体部を含む砥石は切れ味が良好であり、加工面の表面粗さを非常に小さくすることができる。一方、砥粒本体部の平均粒径が１．０μｍ以上である場合、加工面の表面粗さが大きくなり易い傾向がある。上記砥粒本体部の平均粒径の下限は、０．３μｍ以上であることが好ましく、０．４μｍ以上であることがより好ましく、０．５μｍ以上であることが更に好ましい。また、上記砥粒本体部の平均粒径の上限は、０．９μｍ以下であることが好ましく、０．８μｍ以下であることがより好ましく、０．７μｍ以下であることが更に好ましい。また、上記砥粒本体部の平均粒径は、０．３μｍ以上１．０μｍ以下であることが好ましく、０．４μｍ以上０．８μｍ以下であることがより好ましく、０．５μｍ以上０．７μｍ以下であることが更に好ましい。 <Average grain size of the abrasive grain body>
The average grain size of the abrasive grain main body is less than 1.0 μm. A grindstone including the abrasive grain main body has good sharpness, and the surface roughness of the machined surface can be made very small. On the other hand, when the average grain size of the abrasive grain body is 1.0 μm or more, the surface roughness of the machined surface tends to increase. The lower limit of the average particle size of the abrasive grain main body is preferably 0.3 μm or more, more preferably 0.4 μm or more, and even more preferably 0.5 μm or more. Further, the upper limit of the average particle diameter of the abrasive grain main body is preferably 0.9 μm or less, more preferably 0.8 μm or less, and even more preferably 0.7 μm or less. Further, the average particle diameter of the abrasive grain main body is preferably 0.3 μm or more and 1.0 μm or less, more preferably 0.4 μm or more and 0.8 μm or less, and 0.5 μm or more and 0.7 μm or less. It is more preferable that
　超砥粒において、上記砥粒本体部の平均粒径は、以下の方法により特定できる。すなわち、酸化防止膜を化学的処理により除去（方法は材質によって最適なものを選択）した後、砥粒本体部の体積基準のＤ５０を粒度分布計によって測定する。該Ｄ５０を「砥粒本体部の平均粒径」とする。なお、粒度分布計による測定方式は、「レーザー回折方式」とする。 In the superabrasive grain, the average grain size of the abrasive grain main body can be specified by the following method. That is, after removing the antioxidant film by chemical treatment (the most suitable method is selected depending on the material), the volume-based D50 of the main body of the abrasive grain is measured using a particle size distribution meter. The D50 is defined as the "average particle diameter of the abrasive grain main body". Note that the measurement method using the particle size distribution meter is the "laser diffraction method."
　＜砥粒本体部の結晶組織＞
　砥粒本体部の結晶組織は、単結晶又は多結晶とすることができる。砥粒本体部の結晶組織が単結晶であると、砥粒本体部の強度が向上しやすい。一方、砥粒本体部の結晶組織が多結晶であると、該砥粒本体部を含む砥粒を用いた工具の研削比が向上しやすい。 <Crystal structure of the abrasive grain body>
The crystal structure of the abrasive grain main body can be single crystal or polycrystal. When the crystal structure of the abrasive grain body is single crystal, the strength of the abrasive grain body tends to improve. On the other hand, when the crystal structure of the abrasive grain main body is polycrystalline, the grinding ratio of a tool using an abrasive grain including the abrasive grain main body tends to be improved.
　砥粒本体部の結晶組織は、Ｘ線回折により確認することができる。 The crystal structure of the abrasive grain main body can be confirmed by X-ray diffraction.
　≪酸化防止膜≫
　本実施形態に係る超砥粒は、上記砥粒本体部の表面の少なくとも一部を被覆する酸化防止膜を備える。ここで、「砥粒本体部の表面の少なくとも一部を被覆する」とは、「砥粒本体部の表面の全てを被覆する」場合のみならず（図１）、「砥粒本体部の表面の一部のみを被覆する」場合（図２）をも包含する概念である。 <<Antioxidant film>>
The superabrasive according to this embodiment includes an oxidation-preventing film that covers at least a portion of the surface of the abrasive main body. Here, "coating at least a part of the surface of the abrasive grain body" means not only "coating the entire surface of the abrasive grain body" (Figure 1), but also "covering the entire surface of the abrasive grain body" (Fig. 1). This concept also includes the case of "covering only a part of the surface" (FIG. 2).
　＜酸化防止膜の組成＞
　上記酸化防止膜は、後述する第１材料からなることが好ましい。ここで、「第１材料からなる」とは、上記第１材料のみからなる態様に限られず、本開示の効果が奏される限りにおいて、上記第１材料に加えて上記第１材料以外の成分（例えば、不可避不純物）を含む態様をも包含する概念である。上記酸化防止膜の不可避不純物としては、例えばＣ、Ａｌ、Ｓｉが挙げられる。上記酸化防止膜の不可避不純物の含有率は、例えば、質量基準で、０％以上１％以下とすることができる。上記酸化防止膜の組成は、ＩＣＰ発光分光分析法（高周波誘導結合プラズマ発光分光分析法）により特定できる。 <Composition of antioxidant film>
The anti-oxidation film is preferably made of a first material described below. Here, "consisting of the first material" is not limited to an embodiment consisting only of the above first material, but as long as the effects of the present disclosure are achieved, components other than the above first material in addition to the above first material are used. This concept also includes embodiments containing (for example, unavoidable impurities). Examples of unavoidable impurities in the anti-oxidation film include C, Al, and Si. The content of unavoidable impurities in the antioxidant film can be, for example, 0% or more and 1% or less on a mass basis. The composition of the above-mentioned antioxidant film can be determined by ICP emission spectroscopy (high frequency inductively coupled plasma emission spectroscopy).
　（第１材料）
　上記第１材料は、セラミックスまたはガラスからなることが好ましい。これによって、砥石の製造において、砥粒の熱劣化を更に抑制することができる為、砥石により優れた切れ味とより優れた耐摩耗性とを兼備させることができ、より優れた研削性能を備えさせることができる。 (First material)
Preferably, the first material is made of ceramic or glass. As a result, thermal deterioration of the abrasive grains can be further suppressed in the production of whetstones, allowing the whetstone to have both superior sharpness and better abrasion resistance, resulting in better grinding performance. be able to.
　上記セラミックスとしては、周期表の第４族元素、第５族元素、第６族元素、アルミニウム（Ａｌ）、及びケイ素（Ｓｉ）からなる群より選択される１種以上の第１元素と、酸素、窒素、炭素及び硼素からなる群より選ばれる少なくとも１種の第２元素とからなる化合物が挙げられる。第１材料が上記セラミックスである場合、そのような第１材料からなる酸化防止膜は優れた硬度と優れた耐摩耗性とを有する為、砥粒本体部は損傷し難い。なお、周期表の第４族元素は、チタン（Ｔｉ）、ジルコニウム（Ｚｒ）、ハフニウム（Ｈｆ）である。周期表の第５族元素は、バナジウム（Ｖ）、ニオブ（Ｎｂ）、タンタル（Ｔａ）である。周期表の第６族元素は、クロム（Ｃｒ）、モリブデン（Ｍｏ）、タングステン（Ｗ）である。 The ceramics include one or more first elements selected from the group consisting of Group 4 elements, Group 5 elements, Group 6 elements of the periodic table, aluminum (Al), and silicon (Si), and oxygen. , and at least one second element selected from the group consisting of nitrogen, carbon, and boron. When the first material is the above-mentioned ceramic, the oxidation-preventing film made of such a first material has excellent hardness and excellent wear resistance, so that the abrasive grain main body portion is not easily damaged. Note that the Group 4 elements of the periodic table are titanium (Ti), zirconium (Zr), and hafnium (Hf). Group 5 elements of the periodic table are vanadium (V), niobium (Nb), and tantalum (Ta). Group 6 elements of the periodic table are chromium (Cr), molybdenum (Mo), and tungsten (W).
　第１元素と酸素とからなる化合物（酸化物）としては、例えば、酸化チタン（ＴｉＯ２）、酸化ジルコニウム（ＺｒＯ２）、酸化ハフニウム（ＨｆＯ２）、酸化バナジウム（Ｖ２Ｏ５）、酸化ニオブ（Ｎｂ２Ｏ５）、酸化タンタル（Ｔａ２Ｏ５）、酸化クロム（Ｃｒ２Ｏ３）、酸化モリブデン（ＭｏＯ３）、酸化タングステン（ＷＯ３）、酸化アルミニウム（Ａｌ２Ｏ３）、酸化珪素（ＳｉＯ２）を挙げることができる。 Examples of compounds (oxides) consisting of the first element and oxygen include titanium oxide (TiO 2 ), zirconium oxide (ZrO 2 ), hafnium oxide (HfO 2 ), vanadium oxide (V 2 O 5 ), and niobium oxide. (Nb 2 O 5 ), tantalum oxide (Ta 2 O 5 ), chromium oxide (Cr 2 O 3 ), molybdenum oxide (MoO 3 ), tungsten oxide (WO 3 ), aluminum oxide (Al 2 O 3 ), silicon oxide (SiO 2 ) can be mentioned.
　第１元素と窒素とからなる化合物（窒化物）としては、例えば、窒化チタン（ＴｉＮ）、窒化ジルコニウム（ＺｒＮ）、窒化ハフニウム（ＨｆＮ）、窒化バナジウム（ＶＮ）、窒化ニオブ（ＮｂＮ）、窒化タンタル（ＴａＮ）、窒化クロム（Ｃｒ２Ｎ）、窒化モリブデン（ＭｏＮ）、窒化タングステン（ＷＮ）、窒化チタンジルコニウム（ＴｉＺｒＮ）、窒化チタンハフニウム（ＴｉＨｆＮ）、窒化チタンバナジウム（ＴｉＶＮ）、窒化チタンニオブ（ＴｉＮｂＮ）、窒化チタンタンタル（ＴｉＴａＮ）、窒化チタンクロム（ＴｉＣｒＮ）、窒化チタンモリブデン（ＴｉＭｏＮ）、窒化チタンタングステン（ＴｉＷＮ）、窒化ジルコニウムハフニウム（ＺｒＨｆＮ）、窒化ジルコニウムバナジウム（ＺｒＶＮ）、窒化ジルコニウムニオブ（ＺｒＮｂＮ）、窒化ジルコニウムタンタル（ＺｒＴａＮ）、窒化ジルコニウムクロム（ＺｒＣｒＮ）、窒化ジルコニウムモリブデン（ＺｒＭｏＮ）、窒化ジルコニウムタングステン（ＺｒＷＮ）、窒化ハフニウムバナジウム（ＨｆＶＮ）、窒化ハフニウムニオブ（ＨｆＮｂＮ）、窒化ハフニウムタンタル（ＨｆＴａＮ）、窒化ハフニウムクロム（ＨｆＣｒＮ）、窒化ハフニウムモリブデン（ＨｆＭｏＮ）、窒化ハフニウムタングステン（ＨｆＷＮ）、窒化バナジウムニオブ（ＶＮｂＮ）、窒化バナジウムタンタル（ＶＴａＮ）、窒化バナジウムクロム（ＶＣｒＮ）、窒化バナジウムモリブデン（ＶＭｏＮ）、窒化バナジウムタングステン（ＶＷＮ）、窒化ニオブタンタル（ＮｂＴａＮ）、窒化ニオブクロム（ＮｂＣｒＮ）、窒化ニオブモリブデン（ＮｂＭｏＮ）、窒化ニオブタングステン（ＮｂＷＮ）、窒化タンタルクロム（ＴａＣｒＮ）、窒化タンタルモリブデン（ＴａＭｏＮ）、窒化タンタルタングステン（ＴａＷＮ）、窒化クロムモリブデン（ＣｒＭｏＮ）、窒化クロムタングステン（ＣｒＷＮ）、窒化モリブデンタングステン（ＭｏＷＮ）、窒化アルミニウム（ＡｌＮ）、窒化ケイ素（Ｓｉ３Ｎ４）を挙げることができる。 Examples of compounds (nitrides) consisting of the first element and nitrogen include titanium nitride (TiN), zirconium nitride (ZrN), hafnium nitride (HfN), vanadium nitride (VN), niobium nitride (NbN), and tantalum nitride. (TaN), chromium nitride ( Cr2N ), molybdenum nitride (MoN), tungsten nitride (WN), titanium zirconium nitride (TiZrN), titanium hafnium nitride (TiHfN), titanium vanadium nitride (TiVN), titanium niobium nitride (TiNbN) , titanium tantalum nitride (TiTaN), titanium chromium nitride (TiCrN), titanium molybdenum nitride (TiMoN), titanium tungsten nitride (TiWN), zirconium hafnium nitride (ZrHfN), zirconium vanadium nitride (ZrVN), zirconium niobium nitride (ZrNbN), Zirconium tantalum nitride (ZrTaN), zirconium chromium nitride (ZrCrN), zirconium molybdenum nitride (ZrMoN), zirconium tungsten nitride (ZrWN), hafnium vanadium nitride (HfVN), hafnium niobium nitride (HfNbN), hafnium tantalum nitride (HfTaN), nitride Hafnium chromium (HfCrN), hafnium molybdenum nitride (HfMoN), hafnium tungsten nitride (HfWN), vanadium niobium nitride (VNbN), vanadium tantalum nitride (VTaN), vanadium chromium nitride (VCrN), vanadium molybdenum nitride (VMoN), vanadium nitride Tungsten (VWN), niobium tantalum nitride (NbTaN), niobium chromium nitride (NbCrN), niobium molybdenum nitride (NbMoN), niobium tungsten nitride (NbWN), tantalum chromium nitride (TaCrN), tantalum molybdenum nitride (TaMoN), tantalum tungsten nitride ( Examples include TaWN), chromium molybdenum nitride (CrMoN), chromium tungsten nitride (CrWN), molybdenum tungsten nitride (MoWN), aluminum nitride (AlN), and silicon nitride (Si 3 N 4 ).
　第１元素と炭素とからなる化合物（炭化物）としては、例えば、炭化チタン（ＴｉＣ）、炭化ジルコニウム（ＺｒＣ）、炭化ハフニウム（ＨｆＣ）、炭化バナジウム（ＶＣ）、炭化ニオブ（ＮｂＣ）、炭化タンタル（ＴａＣ）、炭化クロム（Ｃｒ２Ｃ）、炭化モリブデン（ＭｏＣ）、炭化タングステン（ＷＣ）、炭化チタンジルコニウム（ＴｉＺｒＣ）、炭化チタンハフニウム（ＴｉＨｆＣ）、炭化チタンバナジウム（ＴｉＶＣ）、炭化チタンニオブ（ＴｉＮｂＣ）、炭化チタンタンタル（ＴｉＴａＣ）、炭化チタンクロム（ＴｉＣｒＣ）、炭化チタンモリブデン（ＴｉＭｏＣ）、炭化チタンタングステン（ＴｉＷＣ）、炭化ジルコニウムハフニウム（ＺｒＨｆＣ）、炭化ジルコニウムバナジウム（ＺｒＶＣ）、炭化ジルコニウムニオブ（ＺｒＮｂＣ）、炭化ジルコニウムタンタル（ＺｒＴａＣ）、炭化ジルコニウムクロム（ＺｒＣｒＣ）、炭化ジルコニウムモリブデン（ＺｒＭｏＣ）、炭化ジルコニウムタングステン（ＺｒＷＣ）、炭化ハフニウムバナジウム（ＨｆＶＣ）、炭化ハフニウムニオブ（ＨｆＮｂＣ）、炭化ハフニウムタンタル（ＨｆＴａＣ）、炭化ハフニウムクロム（ＨｆＣｒＣ）、炭化ハフニウムモリブデン（ＨｆＭｏＣ）、炭化ハフニウムタングステン（ＨｆＷＣ）、炭化バナジウムニオブ（ＶＮｂＣ）、炭化バナジウムタンタル（ＶＴａＣ）、炭化バナジウムクロム（ＶＣｒＣ）、炭化バナジウムモリブデン（ＶＭｏＣ）、炭化バナジウムタングステン（ＶＷＣ）、炭化ニオブタンタル（ＮｂＴａＣ）、炭化ニオブクロム（ＮｂＣｒＣ）、炭化ニオブモリブデン（ＮｂＭｏＣ）、炭化ニオブタングステン（ＮｂＷＣ）、炭化タンタルクロム（ＴａＣｒＣ）、炭化タンタルモリブデン（ＴａＭｏＣ）、炭化タンタルタングステン（ＴａＷＣ）、炭化クロムモリブデン（ＣｒＭｏＣ）、炭化クロムタングステン（ＣｒＷＣ）、炭化モリブデンタングステン（ＭｏＷＣ）、炭化アルミニウム（Ａｌ４Ｃ３）、炭化珪素（ＳｉＣ）を挙げることができる。 Examples of compounds (carbides) consisting of the first element and carbon include titanium carbide (TiC), zirconium carbide (ZrC), hafnium carbide (HfC), vanadium carbide (VC), niobium carbide (NbC), and tantalum carbide ( TaC), chromium carbide ( Cr2C ), molybdenum carbide (MoC), tungsten carbide (WC), titanium zirconium carbide (TiZrC), titanium hafnium carbide (TiHfC), titanium vanadium carbide (TiVC), titanium niobium carbide (TiNbC), Titanium tantalum carbide (TiTaC), titanium chromium carbide (TiCrC), titanium molybdenum carbide (TiMoC), titanium tungsten carbide (TiWC), zirconium hafnium carbide (ZrHfC), zirconium vanadium carbide (ZrVC), zirconium niobium carbide (ZrNbC), carbide Zirconium tantalum (ZrTaC), zirconium chromium carbide (ZrCrC), zirconium molybdenum carbide (ZrMoC), zirconium tungsten carbide (ZrWC), hafnium vanadium carbide (HfVC), hafnium niobium carbide (HfNbC), hafnium tantalum carbide (HfTaC), hafnium carbide Chromium (HfCrC), hafnium molybdenum carbide (HfMoC), hafnium tungsten carbide (HfWC), vanadium niobium carbide (VNbC), vanadium tantalum carbide (VTaC), vanadium chromium carbide (VCrC), vanadium molybdenum carbide (VMoC), vanadium tungsten carbide (VWC), niobium tantalum carbide (NbTaC), niobium chromium carbide (NbCrC), niobium molybdenum carbide (NbMoC), niobium tungsten carbide (NbWC), tantalum chromium carbide (TaCrC), tantalum molybdenum carbide (TaMoC), tantalum tungsten carbide (TaWC) ), chromium molybdenum carbide (CrMoC), chromium tungsten carbide (CrWC), molybdenum tungsten carbide (MoWC), aluminum carbide (Al 4 C 3 ), and silicon carbide (SiC).
　第１元素と炭素と窒素とからなる化合物（炭窒化物）としては、例えば、炭窒化チタン（ＴｉＣＮ）、炭窒化ジルコニウム（ＺｒＣＮ）、炭窒化ハフニウム（ＨｆＣＮ）、炭窒化アルミニウム（ＡｌＣＮ）、炭窒化珪素（ＳｉＣＮ）を挙げることができる。 Examples of compounds (carbonitrides) consisting of the first element, carbon, and nitrogen include titanium carbonitride (TiCN), zirconium carbonitride (ZrCN), hafnium carbonitride (HfCN), aluminum carbonitride (AlCN), and carbonitride. Silicon nitride (SiCN) can be mentioned.
　第１元素と硼素とからなる化合物（硼化物）としては、例えば、硼化チタン（ＴｉＢ２）、硼化ジルコニウム（ＺｒＢ２）、硼化ハフニウム（ＨｆＢ２）、硼化バナジウム（ＶＢ２）、硼化ニオブ（ＮｂＢ２）、硼化タンタル（ＴａＢ２）、硼化クロム（ＣｒＢ２）、硼化モリブデン（ＭｏＢ２）、硼化タングステン（ＷＢ）、硼化アルミニウム（ＡｌＢ２）、硼化珪素（ＳｉＢ４）を挙げることができる。 Examples of compounds (borides) consisting of the first element and boron include titanium boride (TiB 2 ), zirconium boride (ZrB 2 ), hafnium boride (HfB 2 ), vanadium boride (VB 2 ), Niobium boride (NbB 2 ), tantalum boride (TaB 2 ), chromium boride (CrB 2 ), molybdenum boride (MoB 2 ), tungsten boride (WB), aluminum boride (AlB 2 ), silicon boride (SiB 4 ) can be mentioned.
　第１元素と窒素と酸素とからなる化合物（酸窒化物）としては、例えば、酸窒化チタン（ＴｉＯＮ）、酸窒化ジルコニウム（ＺｒＯＮ）、酸窒化ハフニウム（ＨｆＯＮ）、酸窒化バナジウム（ＶＯＮ）、酸窒化ニオブ（ＮｂＯＮ）、酸窒化タンタル（ＴａＯＮ）、酸窒化クロム（ＣｒＯＮ）、酸窒化モリブデン（ＭｏＯＮ）、酸窒化タングステン（ＷＯＮ）、酸窒化アルミニウム（ＡｌＯＮ）、酸窒化珪素（ＳｉＯＮ）、サイアロン（ＳｉＡｌＯＮ）を挙げることができる。 Examples of compounds (oxynitrides) consisting of the first element, nitrogen, and oxygen include titanium oxynitride (TiON), zirconium oxynitride (ZrON), hafnium oxynitride (HfON), vanadium oxynitride (VON), and Niobium nitride (NbON), tantalum oxynitride (TaON), chromium oxynitride (CrON), molybdenum oxynitride (MoON), tungsten oxynitride (WON), aluminum oxynitride (AlON), silicon oxynitride (SiON), Sialon ( SiAlON).
　上記の化合物は、１種類を用いてもよいし、２種類以上を組み合わせて用いてもよい。
　第１材料は、上記の化合物由来の固溶体を含むことができる。ここで、上記の化合物由来の固溶体とは、２種類以上の上記の化合物が互いの結晶構造内に溶け込んでいる状態を意味し、侵入型固溶体や置換型固溶体を意味する。 The above compounds may be used alone or in combination of two or more.
The first material can include a solid solution derived from the compound described above. Here, the solid solution derived from the above compound means a state in which two or more types of the above compounds are dissolved in each other's crystal structure, and means an interstitial solid solution or a substitutional solid solution.
　上記ガラスとしては、例えばホウケイ酸ガラス（ＳｉＯ２、Ｂ２Ｏ３、Ａｌ２Ｏ３、Ｆｅ２Ｏ３、ＣａＯ、ＭｇＯ、Ｎａ２Ｏ、及びＫ２Ｏを含むガラス）が挙げられる。これによって、第１材料が上記ガラスである場合、そのような第１材料からなる酸化防止膜は優れた硬度と優れた耐摩耗性とを有する為、砥粒本体部は損傷し難い。 Examples of the glass include borosilicate glass (glass containing SiO 2 , B 2 O 3 , Al 2 O 3 , Fe 2 O 3 , CaO, MgO, Na 2 O, and K 2 O). As a result, when the first material is the above-mentioned glass, the anti-oxidation film made of the first material has excellent hardness and excellent abrasion resistance, so that the abrasive grain main body is not easily damaged.
　上記超砥粒は、上記第１材料を０．１質量％以上５０質量％未満で含むことが好ましい。これによって、砥石の製造において、砥粒の熱劣化を更に抑制することができる為、砥石により優れた切れ味とより優れた耐摩耗性とを兼備させることができる。超砥粒の第１材料の含有率の下限は、砥粒の熱劣化の抑制する観点から、０．１質量％以上が好ましく、１質量％以上がより好ましく、１０質量％以上が更に好ましい。超砥粒の第１材料の含有率の上限は、４９質量％以下が好ましく、４０質量％以下がより好ましく、３０質量％以下が更に好ましい。 The superabrasive grains preferably contain the first material in an amount of 0.1% by mass or more and less than 50% by mass. As a result, thermal deterioration of the abrasive grains can be further suppressed in the production of the whetstone, so that the whetstone can have both excellent sharpness and better wear resistance. The lower limit of the content of the first material in the superabrasive grains is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 10% by mass or more, from the viewpoint of suppressing thermal deterioration of the abrasive grains. The upper limit of the content of the first material of the superabrasive grains is preferably 49% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less.
　上記超砥粒における上記第１材料の含有率は、以下の手順で測定される。 The content of the first material in the superabrasive grains is measured by the following procedure.
（Ａ１）超砥粒を１ｇ準備する。 (A1) Prepare 1 g of superabrasive grains.
（Ｂ１）第１材料がセラミックスである場合には、上記超砥粒に対してＩＣＰ発光分光分析法（高周波誘導結合プラズマ発光分光分析法）を実行することにより、第１材料を構成する上記第１元素（周期表の第４族元素、第５族元素、第６族元素、アルミニウム（Ａｌ）、及びケイ素（Ｓｉ））の濃度を測定する。該第１元素の濃度に基づき、該第１元素の化合物（酸化物、炭化物、窒化物、炭窒化物、または硼化物）濃度を換算し、該第１元素の化合物の質量を算出する。また、第１材料がガラスである場合には、上記超砥粒に対してＩＣＰ発光分光分析法を実行することにより、第１材料を構成するガラスに含まれる酸素以外の元素（例えば、ケイ素（Ｓｉ）、硼素（Ｂ）、アルミニウム（Ａｌ）、鉄（Ｆｅ）、カルシウム（Ｃａ）、マグネシウム（Ｍｇ）、ナトリウム（Ｎａ）、及びカリウム（Ｋ））の濃度を測定する。該「ガラスに含まれる酸素以外の元素」の濃度に基づき、該「ガラスに含まれる酸素以外の元素」の酸化物の濃度を換算し、該「ガラスに含まれる酸素以外の元素」の酸化物の質量を算出する。 (B1) When the first material is ceramic, the superabrasive grains are subjected to ICP emission spectroscopy (high-frequency inductively coupled plasma emission spectroscopy). The concentration of one element (group 4 element, group 5 element, group 6 element of the periodic table, aluminum (Al), and silicon (Si)) is measured. Based on the concentration of the first element, the concentration of the compound (oxide, carbide, nitride, carbonitride, or boride) of the first element is converted to calculate the mass of the compound of the first element. In addition, when the first material is glass, by performing ICP emission spectroscopy on the superabrasive grains, elements other than oxygen (for example, silicon ( Measure the concentrations of Si), boron (B), aluminum (Al), iron (Fe), calcium (Ca), magnesium (Mg), sodium (Na), and potassium (K)). Based on the concentration of the "element other than oxygen contained in the glass", convert the concentration of the oxide of the "element other than oxygen contained in the glass", and calculate the oxide of the "element other than oxygen contained in the glass". Calculate the mass of
（Ｃ１）超砥粒全体の質量（１ｇ）に対する上記第１元素の化合物の質量の百分率を算出する。該百分率が、超砥粒における第１材料の含有率に該当する。 (C1) Calculate the percentage of the mass of the compound of the first element with respect to the mass (1 g) of the entire superabrasive grain. This percentage corresponds to the content of the first material in the superabrasive grains.
　上記酸化防止膜は、上記砥粒本体部の表面の２０％以上を被覆することが好ましい。これによって、砥石の製造において、砥粒の熱劣化を更に抑制することができる為、砥石により優れた切れ味とより優れた耐摩耗性とを兼備させることができ、より優れた研削性能を備えさせることができる。上記酸化防止膜は、上記砥粒本体部の表面の５０％以上を被覆することがより好ましく、７０％以上を被覆することが更に好ましい。また、上記酸化防止膜は、上記砥粒本体部の表面の１００％を被覆することがより好ましい。製造上の観点で、上記酸化防止膜は、上記砥粒本体部の表面の９９％以下、９８％以下、９７％以下を被覆することができる。また、上記酸化防止膜は、上記砥粒本体部の表面の２０％以上１００％以下を被覆することが好ましく、５０％以上１００％以下を被覆することがより好ましく、７０％以上１００％以下を被覆することが更に好ましい。 The antioxidant film preferably covers 20% or more of the surface of the abrasive grain body. As a result, thermal deterioration of the abrasive grains can be further suppressed in the production of whetstones, allowing the whetstone to have both superior sharpness and better abrasion resistance, resulting in better grinding performance. be able to. The antioxidant film more preferably covers 50% or more of the surface of the abrasive grain main body, and still more preferably covers 70% or more. Moreover, it is more preferable that the antioxidant film covers 100% of the surface of the abrasive grain main body. From a manufacturing standpoint, the antioxidant film can cover 99% or less, 98% or less, or 97% or less of the surface of the abrasive grain main body. Further, the antioxidant film preferably covers 20% or more and 100% or less of the surface of the abrasive grain body, more preferably 50% or more and 100% or less, and 70% or more and 100% or less. More preferably, it is coated.
　上記超砥粒において、上記酸化防止膜が上記砥粒本体部の表面を被覆する割合は、以下の方法により特定できる。 In the superabrasive grain, the proportion of the surface of the abrasive grain body covered with the antioxidant film can be determined by the following method.
（ａ１）エネルギー分散型Ｘ線分析（ＥＤＳ）を備える走査電子顕微鏡（ＳＥＭ）を用いて、５，０００～２００，０００倍の倍率で観察して、上記超砥粒の反射電子像を得る。該反射電子像中に測定領域を設定する。該測定領域は、該測定領域中に超砥粒が１００個以上含まれるように設定される。 (a1) Observe at a magnification of 5,000 to 200,000 times using a scanning electron microscope (SEM) equipped with energy dispersive X-ray analysis (EDS) to obtain a backscattered electron image of the superabrasive grain. A measurement area is set in the backscattered electron image. The measurement area is set so that 100 or more superabrasive grains are included in the measurement area.
（ｂ１）上記反射電子像に対して画像解析ソフト（三谷商事社製の「ＷｉｎＲｏｏｆ」（商標））を用いてＥＤＳにより超砥粒の元素をマッピング分析することによって、上記測定領域において、超砥粒全体が占める面積Ａ１を測定する。 (b1) By mapping the elements of the superabrasive grains using EDS on the backscattered electron image using image analysis software (“WinRoof” (trademark) manufactured by Mitani Shoji Co., Ltd.), The area A1 occupied by the entire grain is measured.
（ｃ１）上記測定領域において、ＥＤＳにより、第１材料の構成元素をマッピング分析することにより、上記酸化防止膜を特定し、上記測定領域において、該酸化防止膜が占める面積Ａ２を測定する（図示なし）。マッピング分析が行われる上記第１材料の構成元素は、炭素、硼素及び窒素以外の元素とする。 (c1) In the measurement region, identify the antioxidant film by mapping and analyzing the constituent elements of the first material using EDS, and measure the area A2 occupied by the antioxidant film in the measurement region (as shown in the figure). none). The constituent elements of the first material on which the mapping analysis is performed are elements other than carbon, boron, and nitrogen.
（ｄ１）上記Ａ２を上記Ａ１で除することにより、酸化防止膜が砥粒本体部の表面を被覆する割合を算出する。 (d1) By dividing the above A2 by the above A1, the proportion of the surface of the abrasive grain body covered by the antioxidant film is calculated.
　≪超砥粒の熱重量分析における残存率≫
　上記超砥粒の熱重量分析における残存率は、７０％以上であることが好ましい。ここで、上記熱重量分析は、温度９００℃かつ保持時間０．５時間の条件下で実行される。これによって、砥石の製造において、超砥粒の熱劣化を更に抑制することができる為、砥石により優れた切れ味とより優れた耐摩耗性とを兼備させることができ、より優れた研削性能を備えさせることができる。上記超砥粒の熱重量分析における残存率の下限は、８０％以上であることがより好ましく、９０％以上であることが更に好ましい。また、上記超砥粒の熱重量分析における残存率の上限は、１００％以下であることが好ましい。上記超砥粒の熱重量分析における残存率は、製造上の観点で９９．５％以下、９９．０％以下、９８．５％以下とすることができる。上記超砥粒の熱重量分析における残存率は、７０％以上１００％以下であることが好ましく、８０％以上１００％以下であることがより好ましく、９０％以上１００％以下であることが更に好ましい。 ≪Residual rate in thermogravimetric analysis of superabrasive particles≫
The residual rate of the superabrasive grains in thermogravimetric analysis is preferably 70% or more. Here, the thermogravimetric analysis is performed under conditions of a temperature of 900° C. and a holding time of 0.5 hours. This makes it possible to further suppress thermal deterioration of the superabrasive grains in the production of grinding wheels, allowing the grinding wheels to have both superior sharpness and better wear resistance, resulting in better grinding performance. can be done. The lower limit of the residual rate in thermogravimetric analysis of the superabrasive grains is more preferably 80% or more, and even more preferably 90% or more. Further, the upper limit of the residual rate in thermogravimetric analysis of the superabrasive grains is preferably 100% or less. The residual rate of the superabrasive grains in thermogravimetric analysis can be set to 99.5% or less, 99.0% or less, or 98.5% or less from the viewpoint of manufacturing. The residual rate of the superabrasive grains in thermogravimetric analysis is preferably 70% or more and 100% or less, more preferably 80% or more and 100% or less, and even more preferably 90% or more and 100% or less. .
　上記超砥粒の熱重量分析における残存率は、上記超砥粒に対し、温度９００℃かつ保持時間０．５時間の条件下で、以下の様な熱重量分析を実行することにより特定できる。超砥粒３０ｍｇ（初期重量）を準備し、熱重量分析（ＴＧ）計にかける（該ＴＧ計は昇温中の物質の重量変化をリアルタイムで測定できる）。ＴＧ測定の条件として、昇温速度１０℃／分にて室温から９００℃まで昇温した後、３０分間９００℃を維持する。雰囲気は大気である。このときの残存重量を測定する。残存率は、「（残存率）＝［（残存重量）／（初期重量）］×１００」で定義される。 The residual rate of the superabrasive in thermogravimetric analysis can be determined by performing the following thermogravimetric analysis on the superabrasive at a temperature of 900° C. and a holding time of 0.5 hours. 30 mg (initial weight) of superabrasive grains is prepared and applied to a thermogravimetric (TG) meter (the TG meter can measure the weight change of a substance during heating in real time). As conditions for TG measurement, the temperature is raised from room temperature to 900°C at a heating rate of 10°C/min, and then 900°C is maintained for 30 minutes. The atmosphere is atmospheric. The remaining weight at this time is measured. The residual rate is defined as “(residual rate)=[(residual weight)/(initial weight)]×100”.
　≪超砥粒の製造方法≫
　本実施形態に係る超砥粒の製造方法は、立方晶窒化硼素又はダイヤモンドからなる砥粒本体部を準備する工程（以下、「準備工程」とも記す）と、該砥粒本体部の表面に酸化防止膜を形成する工程（以下、「被覆工程」とも記す）とを備えることができる。 ≪Production method of super abrasive grains≫
The method for producing superabrasive grains according to the present embodiment includes a step of preparing an abrasive grain main body made of cubic boron nitride or diamond (hereinafter also referred to as a "preparation step"), and a step of preparing an abrasive grain main body made of cubic boron nitride or diamond, and oxidizing the surface of the abrasive grain main body. The method may include a step of forming a preventive film (hereinafter also referred to as a "coating step").
　＜準備工程＞
　砥粒本体部の原料である立方晶窒化硼素又はダイヤモンドを準備する。立方晶窒化硼素およびダイヤモンドは特に限定されず、公知のものを用いることができる。 <Preparation process>
Cubic boron nitride or diamond, which is the raw material for the abrasive grain body, is prepared. Cubic boron nitride and diamond are not particularly limited, and known ones can be used.
　準備した立方晶窒化硼素又はダイヤモンドからなる砥粒本体部に対して、前処理を行うことができる。前処理としては、熱処理、電子線照射、プラズマ照射、マイクロ波照射が挙げられる。 Pretreatment can be performed on the prepared abrasive grain main body made of cubic boron nitride or diamond. Pretreatment includes heat treatment, electron beam irradiation, plasma irradiation, and microwave irradiation.
　＜被覆工程＞
　次に、準備した砥粒本体部の表面に酸化防止膜を形成する。酸化防止膜の形成は、ゾルゲル法、粉砕したセラミックスまたは粉砕したガラスをバインダとして用いて砥粒本体部に吸着させる方法、粉砕したセラミックスまたは粉砕したガラスを静電的に砥粒本体部に吸着させる方法、化学蒸着法、またはターゲット材を用いたスパッタリングを用いて実行される。該被覆工程において、砥粒本体部の表面に均一に酸化防止膜を形成し易い為、ゾルゲル法を用いることが好ましい。 <Coating process>
Next, an anti-oxidation film is formed on the surface of the prepared abrasive grain main body. The anti-oxidation film can be formed by the sol-gel method, by using crushed ceramics or crushed glass as a binder and adsorbing it to the abrasive grain body, or by electrostatically adsorbing crushed ceramics or crushed glass to the abrasive grain body. method, chemical vapor deposition, or sputtering using a target material. In the coating step, it is preferable to use a sol-gel method since it is easy to uniformly form an antioxidant film on the surface of the abrasive grain body.
　（ゾルゲル法）
　上記第１材料がガラスからなる場合、ゾルゲル法を適用できる。砥粒本体部を、テトラエトキシシランなどに代表されるアルコキシドと混合しておく。これに適当な温度・撹拌条件のもと、水を添加することで、アルコキシドを加水分解・縮重合させることで砥粒本体部をゾルで被覆する。これを乾燥させることでゲル化させたのち、適当な温度で焼結することでゲルをガラスに変え、酸化防止膜を形成することができる。 (Sol-gel method)
When the first material is made of glass, a sol-gel method can be applied. The main body of the abrasive grain is mixed with an alkoxide such as tetraethoxysilane. By adding water to this under appropriate temperature and stirring conditions, the alkoxide is hydrolyzed and polycondensed, thereby coating the main body of the abrasive grain with a sol. This is dried to form a gel, and then sintered at an appropriate temperature to turn the gel into glass and form an antioxidant film.
　（粉砕したセラミックスまたは粉砕したガラスを砥粒本体部に吸着させる方法）
　セラミックまたはガラスは、予め粉砕されているものを用いる。砥粒本体部と、セラミックまたはガラスとをビーズミルなどの方法により、溶媒（例えば、水、アルコールなど）中で均一に混合する。砥粒本体部と、セラミックまたはガラスとの混合比は、所望の粒径、被覆率となるように調整する。この混合工程の途中で、有機バインダ（ポリビニルアルコール（ＰＶＡ）など。上記溶媒の種類によって適切なバインダ種の選定は異なる。）を添加し、該有機バインダと、セラミックまたはガラスとを、該砥粒本体部に吸着させる。 (Method of adsorbing crushed ceramics or crushed glass to the abrasive grain body)
The ceramic or glass used is one that has been crushed in advance. The abrasive grain body and ceramic or glass are uniformly mixed in a solvent (eg, water, alcohol, etc.) by a method such as a bead mill. The mixing ratio of the abrasive grain main body and ceramic or glass is adjusted to obtain the desired grain size and coverage. During this mixing process, an organic binder (such as polyvinyl alcohol (PVA). Selection of the appropriate binder type varies depending on the type of solvent mentioned above) is added, and the organic binder and the ceramic or glass are combined with the abrasive grains. Adsorb it to the main body.
　（化学蒸着法）
　第１材料がセラミックスまたは酸化物から成る場合、化学蒸着法を用いることができる。砥粒本体部は反応管中に静置してある。被覆したい元素を含む、気化し易い化合物（通常ハロゲン化物、水素化物、有機金属化合物など）を気化させ、それを適当なキャリアガスで反応管に導き、反応管中で化学反応（還元・熱分解など）させることで砥粒本体部に被覆を施す。反応には気化させた物質に応じた高温が要求されることがあるが、プラズマ化学蒸着法を用いることで、低温での被覆も可能である。 (chemical vapor deposition method)
If the first material consists of a ceramic or an oxide, chemical vapor deposition methods can be used. The abrasive grain main body is placed in a reaction tube. A compound that easily vaporizes (usually a halide, hydride, organometallic compound, etc.) containing the element to be coated is vaporized and introduced into a reaction tube with an appropriate carrier gas, where it undergoes a chemical reaction (reduction/thermal decomposition). etc.) to coat the abrasive grain body. The reaction may require high temperatures depending on the substance being vaporized, but low temperature coatings are also possible using plasma chemical vapor deposition.
　（スパッタリング）
　上記第１材料がセラミックスからなる場合、被覆条件として以下の条件が挙げられる。これにより、セラミックス（第１材料）からなる酸化防止膜を上記砥粒本体部の表面に形成することができる。
　（被覆条件）
　ターゲット材：アルミニウム（金属）
　雰囲気：真空
　放電電圧：１２５Ｖ以上２５０Ｖ以下
　放電周波数：３Ｈｚ以上１０Ｈｚ以下
　コンデンサ容量：１０μＦ以上５００μＦ以下
　Ｓｈｏｔ数：２，０００以上１００，０００以下 (sputtering)
When the first material is made of ceramics, the following conditions may be mentioned as the coating conditions. Thereby, an oxidation-preventing film made of ceramics (first material) can be formed on the surface of the abrasive grain main body.
(Covering conditions)
Target material: aluminum (metal)
Atmosphere: Vacuum Discharge voltage: 125V or more and 250V or less Discharge frequency: 3Hz or more and 10Hz or less Capacitor capacity: 10μF or more and 500μF or less Number of shots: 2,000 or more and 100,000 or less
　［実施形態２：砥石］
　本開示の一実施形態に係る砥石２０について、図３および図４を用いて説明する。
　本実施形態に係る砥石２０は、
　環状の台金１２０と、
　該台金１２０の表面上に配置された超砥粒層１２と、を備え、
　該超砥粒層１２は、本実施形態１に係る超砥粒１０と、結合材１１とを含み、
　該結合材１１の軟化点は、４００℃以上１０００℃以下である。 [Embodiment 2: Grindstone]
A grindstone 20 according to an embodiment of the present disclosure will be described using FIGS. 3 and 4.
The grindstone 20 according to this embodiment is
a ring-shaped base metal 120;
a superabrasive layer 12 disposed on the surface of the base metal 120;
The superabrasive grain layer 12 includes the superabrasive grains 10 according to the first embodiment and a bonding material 11,
The softening point of the bonding material 11 is 400°C or more and 1000°C or less.
　本開示の一実施形態に係る砥石２０は、優れた研削性能を有することが可能である。その理由は、以下の通りと推察される。 The grindstone 20 according to an embodiment of the present disclosure can have excellent grinding performance. The reason is presumed to be as follows.
　本開示の砥石２０は、環状の台金１２０と、該台金１２０の表面上に配置された超砥粒層１２と、を備える。より具体的には、図３、４に示す様に、砥石２０は、カップ状の台金１２０と、該台金１２０の一方端面１２１（使用面）上に周方向に沿って相互に間隔をあけて配置されて固着された複数個の平板状の超砥粒層１２とから構成される。超砥粒層１２の厚みを規定する面、すなわち厚み方向に沿った面１１３が、台金１２０の一方端面１２１（使用面）に形成された所定幅の円周方向の溝に固着されている。超砥粒層１２の周側端面１１１が砥石２０の回転軸とほぼ平行となり、超砥粒層１２の長さ方向が砥石２０の半径方向となるように各超砥粒層１２が台金１２０の一方端面１２１（使用面）に固着されている。各超砥粒層１２は砥石２０の回転軸にほぼ垂直な作用面１１２を有する。台金１２０（使用面）の中央部には砥石２０の回転軸を挿入するための孔１２２が形成されている。また、該超砥粒層１２は、本実施形態１に係る超砥粒１０を含み、本実施形態１に係る超砥粒１０は、上述の通り、上記砥粒本体部１の表面の少なくとも一部が酸化防止膜２で被覆されている。このため、該超砥粒１０を用いた砥石２０を製造する際の大気中での焼成工程においても、該超砥粒１０と大気中の酸素との燃焼反応を抑制できる。よって、該超砥粒１０の熱劣化及び消失に起因する耐摩耗性の低下を抑制でき、砥石２０の研削性能が向上すると推察される。 The grindstone 20 of the present disclosure includes an annular base metal 120 and a superabrasive grain layer 12 disposed on the surface of the base metal 120. More specifically, as shown in FIGS. 3 and 4, the grinding wheel 20 includes a cup-shaped base metal 120 and a cup-shaped base metal 120, and a pair of metal parts spaced apart from each other along the circumferential direction on one end surface 121 (use surface) of the base metal 120. It is composed of a plurality of flat plate-shaped superabrasive grain layers 12 that are spaced apart and fixed. A surface that defines the thickness of the superabrasive grain layer 12, that is, a surface 113 along the thickness direction, is fixed in a circumferential groove of a predetermined width formed on one end surface 121 (use surface) of the base metal 120. . Each superabrasive layer 12 is attached to the base metal 120 so that the circumferential end surface 111 of the superabrasive layer 12 is substantially parallel to the rotation axis of the grinding wheel 20, and the length direction of the superabrasive layer 12 is in the radial direction of the grinding wheel 20. It is fixed to one end surface 121 (use surface) of. Each superabrasive layer 12 has a working surface 112 substantially perpendicular to the axis of rotation of the grinding wheel 20. A hole 122 for inserting the rotating shaft of the grindstone 20 is formed in the center of the base metal 120 (usable surface). Further, the superabrasive grain layer 12 includes the superabrasive grains 10 according to the present embodiment 1, and the superabrasive grains 10 according to the present embodiment 1 cover at least one surface of the abrasive grain main body 1, as described above. portion is coated with an anti-oxidation film 2. Therefore, even in the firing process in the atmosphere when manufacturing the grindstone 20 using the superabrasive grains 10, the combustion reaction between the superabrasive grains 10 and oxygen in the atmosphere can be suppressed. Therefore, it is presumed that the decrease in wear resistance caused by thermal deterioration and disappearance of the superabrasive grains 10 can be suppressed, and the grinding performance of the grindstone 20 is improved.
　また、本開示の超砥粒１０は、砥石２０の製造工程において結合材１１の軟化温度を下げるための金属類の添加を要しない為、該金属類の水への溶出に起因する砥石２０の耐摩耗性の低下を防ぐことができる。 Furthermore, since the superabrasive grain 10 of the present disclosure does not require the addition of metals to lower the softening temperature of the bonding material 11 in the manufacturing process of the grinding wheel 20, the grinding wheel 20 may be reduced due to elution of the metals into water. Decrease in wear resistance can be prevented.
　更に、上記超砥粒層１２は、結合材１１を含み、該結合材１１の軟化点は、４００℃以上１０００℃以下である。このような結合材は、機械的強度に優れるため、砥石２０は優れた研削性能を有することができる。 Furthermore, the superabrasive layer 12 includes a binder 11, and the softening point of the binder 11 is 400°C or more and 1000°C or less. Since such a bonding material has excellent mechanical strength, the grindstone 20 can have excellent grinding performance.
　よって、本実施形態に係る砥石２０は、優れた研削性能を有することができる。 Therefore, the grindstone 20 according to this embodiment can have excellent grinding performance.
　［台金］
　台金の材質は、ＡｌやＡｌ合金、鉄や鉄合金、炭素工具鋼、高速度工具鋼、合金工具鋼、超硬合金、サーメットなどが挙げられる。台金のサイズ（内・外径、厚さ）は、例えば、砥石を設置するマシニングセンタなどの工作機械のサイズ、即ち被削材のサイズに応じて適宜選択できる。台金としては、公知の砥石の台金を利用できる。 [base money]
Examples of the material of the base metal include Al, Al alloy, iron and iron alloy, carbon tool steel, high speed tool steel, alloy tool steel, cemented carbide, and cermet. The size of the base metal (inner/outer diameter, thickness) can be appropriately selected depending on, for example, the size of a machine tool such as a machining center in which the grindstone is installed, that is, the size of the workpiece. As the base metal, a base metal of a known grindstone can be used.
　［超砥粒層］
　≪超砥粒層の構造≫
　超砥粒層１２は、台金１２０の表面上に配置される（図４）。超砥粒層１２のサイズ（厚さ及び幅）は、台金１２０のサイズ（厚さ及び幅）に応じて適宜選択できる。厚さは、砥石２０の径方向に沿った長さをいい、幅は、砥石２０の軸方向に沿った長さをいう。
　≪超砥粒層の組成≫
　本実施形態に係る超砥粒層は、上記超砥粒と、上記結合材とを含む。上記砥石は、上記超砥粒と、上記結合材とからなることができる。また、上記超砥粒層は、本開示の効果を示す限りにおいて、気孔を含んでも良い。上記砥石において、上記気孔の含有率は、４０体積％以上９５体積％以下とすることができる。 [Super abrasive layer]
≪Structure of super abrasive layer≫
Superabrasive layer 12 is disposed on the surface of base metal 120 (FIG. 4). The size (thickness and width) of the superabrasive grain layer 12 can be appropriately selected depending on the size (thickness and width) of the base metal 120. The thickness refers to the length of the grindstone 20 along the radial direction, and the width refers to the length of the grindstone 20 along the axial direction.
≪Composition of superabrasive layer≫
The superabrasive layer according to this embodiment includes the superabrasive and the bonding material. The above-mentioned grindstone can be made of the above-mentioned superabrasive grains and the above-mentioned bonding material. Further, the superabrasive layer may include pores as long as it exhibits the effects of the present disclosure. In the grindstone, the content of the pores may be 40% by volume or more and 95% by volume or less.
　上記超砥粒層において、上記超砥粒の含有率の下限は、１０体積％以上、１５体積％以上、２０体積％以上が好ましい。また、上記超砥粒層において、上記超砥粒の含有率の上限は、６０体積％以下、５０体積％以下、４０体積％以下が好ましい。また、上記超砥粒層において、上記超砥粒の含有率は、１０体積％以上６０体積％以下、１５体積％以上５０体積％以下、２０体積％以上４０体積％以下が好ましい。超砥粒層において、超砥粒の含有率は、砥石刃先１ｃｍ３を切り出したものから、化学的な処理により砥粒と結合材を分離し、砥粒の重量を測定した後、砥粒の密度（ｇ／ｃｍ３）で除することでその体積を求める。これが１ｃｍ３中に含まれる体積（ｃｍ３）であるため、該体積の数値に１００を乗じることにより特定できる。なお、出願人が測定した限りでは、同一の試料において測定する限りにおいては、砥石刃先の切り出し箇所を任意に設定して上記の手順に従い「超砥粒の含有率」の測定を複数回行っても、測定結果のばらつきは少なく、砥石刃先の切り出し箇所を任意に設定しても恣意的にはならないことが確認された。 In the superabrasive layer, the lower limit of the content of the superabrasive is preferably 10% by volume or more, 15% by volume or more, or 20% by volume or more. Further, in the superabrasive layer, the upper limit of the content of the superabrasive is preferably 60% by volume or less, 50% by volume or less, and 40% by volume or less. Further, in the superabrasive grain layer, the content of the superabrasive grains is preferably 10 vol% or more and 60 vol% or less, 15 vol% or more and 50 vol% or less, and 20 vol% or more and 40 vol% or less. In the super-abrasive layer, the content of super-abrasive grains is determined by separating the abrasive grains and binder from a 1 cm3 piece of the cutting edge of the abrasive stone by chemical treatment, measuring the weight of the abrasive grains, and measuring the weight of the abrasive grains. The volume is determined by dividing by the density (g/cm 3 ). Since this is the volume (cm 3 ) contained in 1 cm 3 , it can be specified by multiplying the numerical value of the volume by 100. In addition, as far as the applicant has measured, as long as the measurements are made on the same sample, the "superabrasive content" has been measured multiple times by arbitrarily setting the cutting point of the grinding wheel edge and following the above procedure. It was also confirmed that there was little variation in the measurement results, and that even if the cutting point of the grindstone edge was set arbitrarily, it would not be arbitrary.
　上記超砥粒層において、上記結合材の含有率の下限は、１体積％以上、２体積％以上、３体積％以上が好ましい。また、上記超砥粒層において、上記結合材の含有率の上限は、３０体積％以下、２０体積％以下、１０体積％以下が好ましい。また、上記超砥粒層において、上記結合材の含有率は、１体積％以上３０体積％以下、２体積％以上２０体積％以下、３体積％以上１０体積％以下が好ましい。超砥粒層において、結合材の含有率は、砥石刃先１ｃｍ３を切り出したものから、化学的な処理により砥粒と結合材とを分離し、結合材の重量を測定した後、結合材の密度（ｇ／ｃｍ３）で除することでその体積を求める。これが１ｃｍ３中に含まれる体積（ｃｍ３）であるため、該体積の数値に１００を乗じることにより特定できる。なお、出願人が測定した限りでは、同一の試料において測定する限りにおいては、砥石刃先の切り出し箇所を任意に設定して上記の手順に従い「結合材の含有率」の測定を複数回行っても、測定結果のばらつきは少なく、砥石刃先の切り出し箇所を任意に設定しても恣意的にはならないことが確認された。 In the superabrasive grain layer, the lower limit of the content of the binder is preferably 1% by volume or more, 2% by volume or more, or 3% by volume or more. Further, in the superabrasive grain layer, the upper limit of the content of the binder is preferably 30% by volume or less, 20% by volume or less, and 10% by volume or less. Further, in the superabrasive grain layer, the content of the binder is preferably 1 volume % or more and 30 volume % or less, 2 volume % or more and 20 volume % or less, and 3 volume % or more and 10 volume % or less. In the super abrasive grain layer, the content of the binder is determined by separating the abrasive grains and the binder from a 1cm3 piece of the cutting edge of the grinding wheel by chemical treatment, measuring the weight of the binder, and determining the content of the binder. The volume is determined by dividing by the density (g/cm 3 ). Since this is the volume (cm 3 ) contained in 1 cm 3 , it can be specified by multiplying the numerical value of the volume by 100. In addition, as far as the applicant has measured, as long as the measurement is made on the same sample, it is possible to arbitrarily set the cutting point of the grinding wheel edge and measure the "bind material content" multiple times according to the above procedure. It was confirmed that there was little variation in the measurement results, and that even if the cutting point of the grindstone edge was set arbitrarily, it would not be arbitrary.
　＜超砥粒＞
　超砥粒としては、実施形態１の超砥粒を用いる。超砥粒の数は複数とすることができる。超砥粒層１２の表面側の超砥粒１０は、その一部が結合材１１から露出しており、その露出箇所が被削材を研削する切刃部を有する。 <Super abrasive>
As the superabrasive grain, the superabrasive grain of Embodiment 1 is used. The number of superabrasive grains can be plural. A portion of the superabrasive grains 10 on the surface side of the superabrasive grain layer 12 is exposed from the bonding material 11, and the exposed portion has a cutting edge portion for grinding the work material.
　一方、超砥粒層１２の台金１２０側の超砥粒１０は、その全てが結合材１１に埋設されている。埋設された超砥粒１０は、砥石２０で被削材を研削中に超砥粒層１２の表面側の超砥粒１０が摩耗して脱落すると共に結合材１１が摩耗する過程で、その一部が結合材１１から露出し被削材を研削する（図４）。 On the other hand, all of the superabrasive grains 10 on the base metal 120 side of the superabrasive grain layer 12 are embedded in the bonding material 11. The buried superabrasive grains 10 are removed during grinding of a workpiece with the grindstone 20, in the process in which the superabrasive grains 10 on the surface side of the superabrasive grain layer 12 wear out and fall off, and the bonding material 11 wears out. The part is exposed from the bonding material 11 and the workpiece is ground (FIG. 4).
　複数の超砥粒は全て、同一構成（材質やサイズ）の砥粒本体部と同一構成（材質や厚さ）の酸化防止膜とで構成されていてもよい。また、一部の超砥粒の砥粒本体部や酸化防止膜は、他部の超砥粒の砥粒本体部や酸化防止膜と異なる構成（材質やサイズ）であってもよい。また、超砥粒層には超砥粒以外の公知の砥粒が混在していてもよい。 All of the plurality of superabrasive grains may be composed of an abrasive grain body portion having the same configuration (material and size) and an oxidation prevention film having the same configuration (material and thickness). Further, the abrasive grain main body portion and oxidation prevention film of some superabrasive grains may have a different configuration (material and size) from the abrasive grain main body portion and oxidation prevention film of other portions of the superabrasive grain. Moreover, known abrasive grains other than superabrasive grains may be mixed in the superabrasive grain layer.
　＜結合材＞
　結合材１１は、超砥粒１０を台金１２０の一方端面１２１（使用面）（図４）に固着する。結合材の種類は、例えば、ビトリファイドボンド、メタルボンド、及びこれらを複合したボンドの中から選択される１種のボンド、又は金属ロウが挙げられる。これらのボンドや金属ロウは、公知のボンドや金属ロウを利用できる。 <Binding material>
The bonding material 11 fixes the superabrasive grains 10 to one end surface 121 (usable surface) of the base metal 120 (FIG. 4). Examples of the type of bonding material include one type of bond selected from vitrified bond, metal bond, and a composite bond of these, or metal solder. As these bonds and metal solders, known bonds and metal solders can be used.
　ビトリファイドボンドは、ガラス質を主成分とすることが挙げられる。メタルボンドは、銅錫合金が挙げられる。金属ロウは、銀（Ａｇ）ロウなどが挙げられる。 One example of vitrified bond is that the main component is glass. Examples of metal bonds include copper-tin alloys. Examples of the metal solder include silver (Ag) solder.
　結合材の種類は、超砥粒の酸化防止膜の材質などに応じて適宜選択できる。例えば、超砥粒の酸化防止膜が導電性を有する場合、結合材は、例えばビトリファイドボンド、メタルボンド、及び金属ロウを利用できる。但し、超砥粒と結合材との親和性の観点で、結合材は、ビトリファイドボンドであることが好ましい。 The type of bonding material can be selected as appropriate depending on the material of the anti-oxidation film of the superabrasive grains. For example, if the anti-oxidation film of the superabrasive grains has conductivity, the bonding material can be, for example, vitrified bond, metal bond, or metal solder. However, from the viewpoint of affinity between the superabrasive grains and the binder, the binder is preferably vitrified bond.
　（結合材の軟化点）
　結合材の軟化点は、４００℃以上１０００℃以下である。このような結合材は、機械的強度に優れるため、砥石は優れた研削性能を有することができる。上記結合材の軟化点の下限は、５００℃以上であることが好ましく、６００℃以上であることがより好ましく、７００℃以上であることが更に好ましい。また、上記結合材の軟化点の上限は、９５０℃以下であることが好ましく、９００℃以下であることがより好ましく、８５０℃以下であることが更に好ましい。また、上記結合材の軟化点は、５００℃以上９５０℃以下であることが好ましく、６００℃以上９００℃以下であることがより好ましく、７００℃以上８５０℃以下であることが更に好ましい。 (Softening point of binding material)
The softening point of the binder is 400°C or more and 1000°C or less. Since such a binding material has excellent mechanical strength, the grindstone can have excellent grinding performance. The lower limit of the softening point of the binder is preferably 500°C or higher, more preferably 600°C or higher, and even more preferably 700°C or higher. Further, the upper limit of the softening point of the binder is preferably 950°C or lower, more preferably 900°C or lower, and even more preferably 850°C or lower. Further, the softening point of the binder is preferably 500°C or more and 950°C or less, more preferably 600°C or more and 900°C or less, and even more preferably 700°C or more and 850°C or less.
　上記軟化点は、熱機械測定（ＴＭＡ）の圧縮モード測定で熱膨張を測定した際、膨張の曲線の曲率が特徴的に変わる２点から直線を外挿し、それらの交点から求めることにより特定できる。 The above-mentioned softening point can be determined by extrapolating a straight line from two points where the curvature of the expansion curve characteristically changes when thermal expansion is measured in compression mode measurement using thermomechanical measurement (TMA), and finding it from the intersection of these points. .
　（結合材の組成）
　上記結合材は、珪素と、硼素と、アルカリ金属元素およびアルカリ土類金属元素からなる群より選択される少なくとも１種の元素とを含み、該結合材の珪素の含有率は、３０質量％以上７０質量％以下であり、該結合材の硼素の含有率は、０質量％以上３０質量％以下であることが好ましい。これによって、上記酸化防止膜を介して、該酸化防止膜を備える超砥粒と結合材との親和性が更に高まる。その結果、砥石はより優れた研削性能を有することができる。なお、アルカリ金属元素として、リチウム（Ｌｉ）、ナトリウム（Ｎａ）、カリウム（Ｋ）、ルビジウム（Ｒｂ）、セシウム（Ｃｓ）、フランシウム（Ｆｒ）が挙げられる。また、アルカリ土類金属元素として、カルシウム（Ｃａ）、ストロンチウム（Ｓｒ）、バリウム（Ｂａ）、ラジウム（Ｒａ）が挙げられる。 (Composition of binding material)
The binder contains silicon, boron, and at least one element selected from the group consisting of alkali metal elements and alkaline earth metal elements, and the silicon content of the binder is 30% by mass or more. It is preferably 70% by mass or less, and the boron content of the bonding material is preferably 0% by mass or more and 30% by mass or less. This further increases the affinity between the superabrasive grains provided with the oxidation-preventing film and the binder via the oxidation-preventing film. As a result, the grindstone can have better grinding performance. Note that examples of the alkali metal elements include lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs), and francium (Fr). Furthermore, examples of alkaline earth metal elements include calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).
　該結合材の珪素の含有率は、４０質量％以上であることがより好ましく、５０質量％以上であることが更に好ましい。該結合材の珪素の含有率は、６０質量％以下であることがより好ましく、５５質量％以下であることが更に好ましい。該結合材の珪素の含有率は、４０質量％以上６０質量％以下であることがより好ましく、５０質量％以上５５質量％以下であることが更に好ましい。 The silicon content of the bonding material is more preferably 40% by mass or more, and even more preferably 50% by mass or more. The silicon content of the bonding material is more preferably 60% by mass or less, and even more preferably 55% by mass or less. The silicon content of the bonding material is more preferably 40% by mass or more and 60% by mass or less, and even more preferably 50% by mass or more and 55% by mass or less.
　該結合材の硼素の含有率は、５質量％以上であることがより好ましく、１０質量％以上であることが更に好ましい。該結合材の硼素の含有率は、２５質量％以下であることがより好ましく、２０質量％以下であることが更に好ましい。該結合材の硼素の含有率は、５質量％以上２５質量％以下であることがより好ましく、１０質量％以上２０質量％以下であることが更に好ましい。 The boron content of the bonding material is more preferably 5% by mass or more, and even more preferably 10% by mass or more. The boron content of the bonding material is more preferably 25% by mass or less, and even more preferably 20% by mass or less. The boron content of the bonding material is more preferably 5% by mass or more and 25% by mass or less, and even more preferably 10% by mass or more and 20% by mass or less.
　上記結合材の組成は、ＩＣＰ発光分光分析法（高周波誘導結合プラズマ発光分光分析法）することにより特定できる。 The composition of the binder can be identified by ICP emission spectroscopy (high frequency inductively coupled plasma emission spectroscopy).
　≪砥石の製造方法≫
　砥石２０（図３および図４）は、砥粒本体部１の表面の少なくとも一部に酸化防止膜２が被覆された複数の超砥粒１０（図１および図２）を準備し、結合材１１により複数の超砥粒１０を台金１２０の一方端面１２１（使用面）に固着することで製造できる（図４）。また、砥石２０は、酸化防止膜２が被覆されていない複数の砥粒本体部１を準備し、結合材１１により複数の砥粒本体部１を台金１２０の一方端面１２１（使用面）に固着した後、砥粒本体部１の表面（切刃部）を覆うように酸化防止膜２を形成することで製造してもよい。この場合、被覆方法は、上述のゾルゲル法、粉砕したセラミックスまたは粉砕したガラスをバインダとして用いて砥粒本体部に吸着させる方法、粉砕したセラミックスまたは粉砕したガラスを静電的に砥粒本体部に吸着させる方法、化学蒸着法、及びターゲット材を用いたスパッタリングのいずれも利用できる。 ≪Whetstone manufacturing method≫
The grinding wheel 20 (FIGS. 3 and 4) is prepared by preparing a plurality of superabrasive grains 10 (FIGS. 1 and 2) in which at least a portion of the surface of the abrasive grain main body 1 is coated with an anti-oxidation film 2, and applying a bonding material. 11, by fixing a plurality of superabrasive grains 10 to one end surface 121 (usable surface) of the base metal 120 (FIG. 4). In addition, the grinding wheel 20 is prepared by preparing a plurality of abrasive grain main bodies 1 that are not coated with the anti-oxidation film 2, and bonding the plurality of abrasive grain main body parts 1 to one end surface 121 (usable surface) of the base metal 120 using a bonding material 11. After the abrasive particles are fixed, the anti-oxidation film 2 may be formed to cover the surface (cutting edge portion) of the abrasive grain body 1. In this case, coating methods include the above-mentioned sol-gel method, a method in which crushed ceramics or crushed glass is adsorbed onto the abrasive grain body using a binder, and a method in which crushed ceramics or crushed glass is electrostatically applied to the abrasive grain body. Any of an adsorption method, a chemical vapor deposition method, and a sputtering method using a target material can be used.
　［用途］
　実施形態に係る砥石は、自動車部品、光学ガラス、磁性材料、半導体材料などの研削や、エンドミル、ドリル、リーマなどの溝研削、刃先交換チップのブレーカ研削、各種工具の重研削に好適に利用できる。 [Application]
The grindstone according to the embodiment can be suitably used for grinding automobile parts, optical glass, magnetic materials, semiconductor materials, etc., groove grinding of end mills, drills, reamers, etc., breaker grinding of indexable tips, and heavy grinding of various tools. .
　以下、本開示の実施例に基づいて具体的に説明するが、本発明は以下の実施例に限定されるものではない。 Hereinafter, the present disclosure will be specifically described based on examples of the present disclosure, but the present invention is not limited to the following examples.
　≪超砥粒の製造≫
　以下のようにして、試料１～試料６、試料９～試料４２の超砥粒を製造した。 ≪Manufacture of super abrasive particles≫
Superabrasive grains of Samples 1 to 6 and Samples 9 to 42 were produced as follows.
　＜準備工程＞
　試料１～試料６、試料９～試料４２に係る超砥粒を作製する為、表１に記載の原料（立方晶窒化硼素（ｃＢＮ）またはダイヤモンド）からなり、且つ表１に記載の平均粒径を有する砥粒本体部を準備した。 <Preparation process>
In order to produce the superabrasive grains according to Samples 1 to 6 and Samples 9 to 42, they are made of the raw materials (cubic boron nitride (cBN) or diamond) listed in Table 1, and have the average grain size listed in Table 1. An abrasive grain main body having the following properties was prepared.
　＜被覆工程＞
　（ゾルゲル法）
　試料２、９に係る超砥粒を作製する為、表１に記載の組成で、上記の砥粒本体部とテトラエトキシシラン（アルコキシド）とを混合することにより混合物を得た。次いで、表１に記載の量の水を添加しながら、表１に記載の撹拌条件で該第１混合物を撹拌することにより、砥粒本体部をゾルで被覆させた。これを表１に記載の条件で乾燥させた後、表１に記載の条件で焼結することで、試料２、９に係る超砥粒を得た。 <Coating process>
(Sol-gel method)
In order to produce superabrasive grains according to Samples 2 and 9, a mixture was obtained by mixing the above abrasive grain main body and tetraethoxysilane (alkoxide) with the composition shown in Table 1. Next, the first mixture was stirred under the stirring conditions shown in Table 1 while adding water in the amount shown in Table 1, thereby coating the abrasive grain body with the sol. After drying this under the conditions listed in Table 1, it was sintered under the conditions listed in Table 1 to obtain superabrasive grains according to Samples 2 and 9.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　（粉砕したセラミックスまたは粉砕したガラスを吸着させる方法）
　試料２４～３７に係る超砥粒を作製する為、表４～５に記載の第１材料であって、予め粉砕されているものを用意した。次いで、上記砥粒本体部と、該第１材料とを水（溶媒）中で、表２に記載の組成でビーズミルを用いて混合しながら、ポリビニルアルコール（ＰＶＡ）（有機バインダ）を表２に記載の量で添加した。これによって、試料２４～３７に係る超砥粒を得た。 (Method of adsorbing crushed ceramics or crushed glass)
In order to produce superabrasive grains according to Samples 24 to 37, the first materials listed in Tables 4 to 5, which had been ground in advance, were prepared. Next, while mixing the abrasive grain main body and the first material in water (solvent) with the composition shown in Table 2 using a bead mill, polyvinyl alcohol (PVA) (organic binder) was added as shown in Table 2. Added in the amounts listed. As a result, superabrasive grains related to Samples 24 to 37 were obtained.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　（スパッタリング）
　試料１、３、１１～２３、３８～４２に係る超砥粒を作製する為、上記砥粒本体部に対し、表３に記載の条件でスパッタリングを実行した。これによって、試料１、３、１１～２３、３８～４２に係る超砥粒を得た。 (sputtering)
In order to produce superabrasive grains according to Samples 1, 3, 11-23, and 38-42, sputtering was performed on the abrasive grain body portions under the conditions listed in Table 3. As a result, superabrasive grains according to Samples 1, 3, 11-23, and 38-42 were obtained.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
　なお、試料４～６、および１０に関し、上記被覆工程は実行されなかった。 Note that for Samples 4 to 6 and 10, the above coating step was not performed.
　以上の工程を実行することにより、表４～５に示した構成を有する試料１～試料６、試料９～試料４２に係る超砥粒を製造した。 By carrying out the above steps, superabrasives according to Samples 1 to 6 and Samples 9 to 42 having the configurations shown in Tables 4 to 5 were manufactured.
　≪超砥粒の特性評価≫
　＜砥粒本体部の平均粒径＞
　試料１～試料６、試料９～試料４２に係る超砥粒について、砥粒本体部の平均粒径を実施形態１に記載の方法により求めた。得られた結果を、表４～５の「平均粒径［μｍ］」欄に記す。 ≪Characteristics evaluation of super abrasive particles≫
<Average grain size of the abrasive grain body>
For the superabrasive grains of Samples 1 to 6 and Samples 9 to 42, the average particle diameter of the abrasive grain body was determined by the method described in Embodiment 1. The obtained results are listed in the "Average particle size [μm]" column of Tables 4 and 5.
　＜超砥粒の熱重量分析における残存率＞
　試料１～試料６、試料９～試料４２に係る超砥粒について、上記超砥粒の熱重量分析における残存率を実施形態１に記載の方法により求めた。得られた結果を、表４～５の「超砥粒」の欄における「熱重量分析残存率［％］」の欄に記す。 <Survival rate in thermogravimetric analysis of superabrasive grains>
Regarding the superabrasive grains of Samples 1 to 6 and Samples 9 to 42, the residual ratio in thermogravimetric analysis of the superabrasive grains was determined by the method described in Embodiment 1. The obtained results are recorded in the "thermogravimetric analysis residual rate [%]" column in the "superabrasive" column of Tables 4 and 5.
　＜超砥粒における第１材料の含有率＞
　試料１～試料６、試料９～試料４２に係る超砥粒について、上記超砥粒における上記第１材料の含有率を実施形態１に記載の方法により求めた。得られた結果を、表４～５の「第１材料含有率［質量％］」の欄に記す。 <Content of first material in superabrasive>
Regarding the superabrasive grains of Samples 1 to 6 and Samples 9 to 42, the content of the first material in the superabrasive grains was determined by the method described in Embodiment 1. The obtained results are listed in the "First material content [mass %]" column of Tables 4 and 5.
　＜酸化防止膜が砥粒本体部の表面を被覆する割合＞
　試料１～試料６、試料９～試料４２に係る超砥粒について、上記酸化防止膜が上記砥粒本体部の表面を被覆する割合を実施形態１に記載の方法により求めた。得られた結果を、表４～５の「砥粒本体部表面被覆率［％］」の欄に記す。 <Ratio that the antioxidant film covers the surface of the abrasive grain body>
Regarding the superabrasive grains of Samples 1 to 6 and Samples 9 to 42, the proportion of the surface of the abrasive grain body covered by the antioxidant film was determined by the method described in Embodiment 1. The obtained results are listed in the column of "Abrasive grain main body surface coverage [%]" in Tables 4 and 5.
　≪砥石の製造≫
　上記試料１～試料６、試料９～試料４２に係る超砥粒、および表４～５に記載の軟化点と組成とを有する結合材と、環状の台金を用いて、砥石（研削ホイール）を製造した。なお、超砥粒の使用量（ｇ）と結合材の使用量（ｇ）とは、表４～５に記載の通りとした。 ≪Manufacture of whetstones≫
Using the superabrasive grains according to Samples 1 to 6 and Samples 9 to 42, and a binder having the softening point and composition shown in Tables 4 to 5, and a ring-shaped base metal, a grinding wheel (grinding wheel) is manufactured. was manufactured. The amount of superabrasive grains used (g) and the amount of binder used (g) were as shown in Tables 4 and 5.
　≪超砥粒層における超砥粒の含有率、および超砥粒層における結合材の含有率≫
　各試料の超砥粒に係る砥石に関し、超砥粒層における超砥粒の含有率を実施形態２に記載の方法により求めた。得られた結果を、表４～５の「超砥粒」の欄における「超砥粒層における含有率［体積％］」の欄に記す。また、各試料の超砥粒に係る砥石に関し、超砥粒層における結合材の含有率を実施形態２に記載の方法により求めた。得られた結果を、表４～５の「結合材」の欄における「超砥粒層における含有率［体積％］」の欄に記す。 ≪Content of superabrasive in the superabrasive layer and content of binder in the superabrasive layer≫
Regarding the grindstone related to the superabrasive grains of each sample, the content rate of the superabrasive grains in the superabrasive grain layer was determined by the method described in Embodiment 2. The obtained results are recorded in the "Content in superabrasive layer [volume %]" column in the "Superabrasive" column of Tables 4 and 5. In addition, regarding the grinding wheel related to the superabrasive grain of each sample, the content of the binder in the superabrasive grain layer was determined by the method described in Embodiment 2. The obtained results are listed in the "Content in superabrasive layer [volume %]" column in the "Binding material" column of Tables 4 and 5.
　≪研削比（切れ味および耐摩耗性）の評価≫
　各試料の超砥粒に係る砥石の切れ味と耐摩耗性との評価は、研削比を求めることで行った。研削比は、以下の装置に各試料の超砥粒に係る砥石を設置し、以下の条件で被削材を研削して、「研削によって除去された被削材の体積／超砥粒の総損耗体積」から求めた。即ち、研削比が高いほど、切れ味と耐摩耗性とが優れ、研削性能が高いことを示す。得られた結果を、表４～５の「研削比」の欄に記す。 ≪Evaluation of grinding ratio (cutting quality and wear resistance)≫
The sharpness and wear resistance of the grinding wheel for each sample using superabrasive grains were evaluated by determining the grinding ratio. The grinding ratio is determined by installing a grinding wheel related to the superabrasive grains of each sample in the following equipment, and grinding the workpiece under the following conditions. It was calculated from "loss volume". That is, the higher the grinding ratio, the better the sharpness and wear resistance, and the higher the grinding performance. The obtained results are listed in the "grinding ratio" column of Tables 4 and 5.
　被削材：ケイ素ウェーハ（Φ１５０ｍｍ×０．７ｍｍ厚）
　装置：ＲＧＳ３４Ｎ（不二越製）
　砥石周速度：４０ｍ／ｓ
　加工厚み：０．０１０ｍｍ
　送り速度：０．０２４ｍｍ／ｍｉｎ
　クーラント：純水 Work material: Silicon wafer (Φ150mm x 0.7mm thick)
Equipment: RGS34N (manufactured by Fujikoshi)
Grinding wheel peripheral speed: 40m/s
Processing thickness: 0.010mm
Feed speed: 0.024mm/min
Coolant: pure water
　なお、上記研削は、図５で示す研削加工方式１００を用いて実行された。より具体的には、研削加工方式１００は、テーブル１１０上に上記被削材１３０を固定した。ここで、テーブル１１０は矢印１１０Ｒで示す方向に回転可能である。砥石２０は、矢印１Ｒで示す方向に回転可能である。さらに矢印１Ｆで示す方向が切込み方向である。 Note that the above grinding was performed using a grinding method 100 shown in FIG. More specifically, in the grinding method 100, the workpiece 130 is fixed on the table 110. Here, the table 110 is rotatable in the direction indicated by an arrow 110R. The grindstone 20 is rotatable in the direction indicated by the arrow 1R. Further, the direction indicated by arrow 1F is the cutting direction.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000005
Figure JPOXMLDOC01-appb-T000005
　上記試料１～３、９、１１～１７、２０～４２は実施例に該当し、上記試料４～６、１０、１８、１９は比較例に該当する。上記試料１～３、９、１１～１７、２０～４２の砥石は、上記試料４～６、１０、１８、１９の砥石に比して、格別に高い研削比を示した。砥粒本体部の平均粒径を同じくする試料同士で比較すると、上記試料１～３、９、１１～１７、２０～４２の砥石は、上記試料４～６、１０、１８、１９の砥石に比して、格別に優れた切れ味と、格別に優れた耐摩耗性とを有する。すなわち、上記試料１～３、９、１１～１７、２０～４２の砥石は、上記試料４～６、１０、１８、１９の砥石に比して、格別に優れた研削性能を有する。 The above samples 1 to 3, 9, 11 to 17, and 20 to 42 correspond to examples, and the above samples 4 to 6, 10, 18, and 19 correspond to comparative examples. The grinding wheels of Samples 1 to 3, 9, 11 to 17, and 20 to 42 exhibited exceptionally high grinding ratios compared to the grinding wheels of Samples 4 to 6, 10, 18, and 19. Comparing samples with the same average particle diameter of the abrasive grain body, the grinding wheels of samples 1 to 3, 9, 11 to 17, and 20 to 42 are superior to those of samples 4 to 6, 10, 18, and 19. In comparison, it has exceptionally excellent sharpness and exceptionally excellent wear resistance. That is, the grindstones of Samples 1 to 3, 9, 11 to 17, and 20 to 42 have exceptionally excellent grinding performance compared to the grindstones of Samples 4 to 6, 10, 18, and 19.
　以上により、試料１～３、９、１１～１７、２０～４２の超砥粒は、砥石に優れた研削性能を備えさせることが分かった。 From the above, it was found that the superabrasive grains of Samples 1 to 3, 9, 11 to 17, and 20 to 42 provided the grindstone with excellent grinding performance.
　以上のように本発明の実施の形態および実施例について説明を行なったが、上述の各実施の形態および実施例の構成を適宜組み合わせることも当初から予定している。 Although the embodiments and examples of the present invention have been described above, it is planned from the beginning to combine the configurations of the above-described embodiments and examples as appropriate.
　今回開示された実施の形態はすべての点で例示であって、制限的なものではないと考えられるべきである。本発明の範囲は上記した実施の形態ではなく請求の範囲によって示され、請求の範囲と均等の意味、および範囲内でのすべての変更が含まれることが意図される。 The embodiments disclosed herein are illustrative in all respects and should not be considered restrictive. The scope of the present invention is indicated by the claims rather than the embodiments described above, and it is intended that equivalent meanings to the claims and all changes within the scope are included.
　１　砥粒本体部、２　酸化防止膜、１０　超砥粒、１１　結合材、２０　砥石、１２　超砥粒層、１１１　周側端面、１１２　作用面、１１３　厚み方向に沿った面、１２０　台金、１２１　端面、１２２　孔、１００　研削加工方式、１３０　被削材、１Ｆ，１Ｒ，１１０Ｒ　矢印 1 Abrasive grain main body, 2 Anti-oxidation film, 10 Super abrasive, 11 Binding material, 20 Grindstone, 12 Super abrasive layer, 111 Circumferential end surface, 112 Working surface, 113 Surface along the thickness direction, 120 Base metal, 121 End face, 122 Hole, 100 Grinding method, 130 Work material, 1F, 1R, 110R Arrow

Claims (7)

  1. 　砥粒本体部と、前記砥粒本体部の表面の少なくとも一部を被覆する酸化防止膜とを備える、超砥粒であって、
    　前記砥粒本体部は、立方晶窒化硼素又はダイヤモンドからなり、
    　前記砥粒本体部の平均粒径は、１．０μｍ未満である、超砥粒。     A superabrasive grain comprising an abrasive grain body portion and an oxidation prevention film covering at least a part of the surface of the abrasive grain body portion,
    The abrasive grain main body is made of cubic boron nitride or diamond,
    A superabrasive grain in which the average grain size of the abrasive grain main body is less than 1.0 μm.
  2. 　前記超砥粒の熱重量分析における残存率は、７０％以上であり、
    　前記熱重量分析は、温度９００℃かつ保持時間０．５時間の条件下で実行される、請求項１に記載の超砥粒。     The residual rate of the superabrasive grains in thermogravimetric analysis is 70% or more,
    The superabrasive according to claim 1, wherein the thermogravimetric analysis is performed at a temperature of 900° C. and a holding time of 0.5 hours.
  3. 　前記酸化防止膜は、第１材料からなり、
    　前記第１材料は、セラミックスまたはガラスからなる、請求項１または請求項２に記載の超砥粒。     The antioxidant film is made of a first material,
    The superabrasive according to claim 1 or 2, wherein the first material is made of ceramics or glass.
  4. 　前記超砥粒は、前記第１材料を０．１質量％以上５０質量％未満で含む、請求項３に記載の超砥粒。 The superabrasive according to claim 3, wherein the superabrasive contains the first material in an amount of 0.1% by mass or more and less than 50% by mass.
  5. 　前記酸化防止膜は、前記砥粒本体部の表面の２０％以上を被覆する、請求項１から請求項４のいずれか１項に記載の超砥粒。 The superabrasive according to any one of claims 1 to 4, wherein the antioxidant film covers 20% or more of the surface of the abrasive grain main body.
  6. 　環状の台金と、
    　前記台金の表面上に配置された超砥粒層と、を備え、
    　前記超砥粒層は、請求項１から請求項５のいずれか１項に記載の超砥粒と、結合材とを含み、
    　前記結合材の軟化点は、４００℃以上１０００℃以下である、砥石。     a ring-shaped base metal,
    a superabrasive layer disposed on the surface of the base metal,
    The superabrasive layer includes the superabrasive according to any one of claims 1 to 5 and a binder,
    A grindstone, wherein the softening point of the binder is 400°C or more and 1000°C or less.
  7. 　前記結合材は、珪素と、硼素と、アルカリ金属元素およびアルカリ土類金属元素からなる群より選択される少なくとも１種の元素とを含み、
    　前記結合材の珪素の含有率は、３０質量％以上７０質量％以下であり、
    　前記結合材の硼素の含有率は、０質量％以上３０質量％以下である、請求項６に記載の砥石。     The binder contains silicon, boron, and at least one element selected from the group consisting of alkali metal elements and alkaline earth metal elements,
    The silicon content of the binder is 30% by mass or more and 70% by mass or less,
    The grindstone according to claim 6, wherein the boron content of the binder is 0% by mass or more and 30% by mass or less.
PCT/JP2022/030622 2022-08-10 2022-08-10 Superabrasive grain and grindstone WO2024034076A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005072912A1 (en) * 2004-01-28 2005-08-11 Kure-Norton Co., Ltd. Method for producing vitrified diamond whetstone
JP2008513566A (en) * 2004-09-23 2008-05-01 エレメント シックス （プロプライエタリイ）リミテッド Coated abrasive material and method for producing the same
JP2017521274A (en) * 2014-07-01 2017-08-03 ダイヤモンド イノヴェーションズ インコーポレイテッド Glass-coated CBN abrasive and method for producing the same

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2005072912A1 (en) * 2004-01-28 2005-08-11 Kure-Norton Co., Ltd. Method for producing vitrified diamond whetstone
JP2008513566A (en) * 2004-09-23 2008-05-01 エレメント シックス （プロプライエタリイ）リミテッド Coated abrasive material and method for producing the same
JP2017521274A (en) * 2014-07-01 2017-08-03 ダイヤモンド イノヴェーションズ インコーポレイテッド Glass-coated CBN abrasive and method for producing the same

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