WO1998021009A1 - Abrasive body and process for manufacturing the same - Google Patents

Abrasive body and process for manufacturing the same Download PDF

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Publication number
WO1998021009A1
WO1998021009A1 PCT/AT1997/000244 AT9700244W WO9821009A1 WO 1998021009 A1 WO1998021009 A1 WO 1998021009A1 AT 9700244 W AT9700244 W AT 9700244W WO 9821009 A1 WO9821009 A1 WO 9821009A1
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WO
WIPO (PCT)
Prior art keywords
sintered
grinding
abrasive
presintered
ceramic
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PCT/AT1997/000244
Other languages
German (de)
French (fr)
Inventor
Edgar Rappold
Gerd Six
Original Assignee
Rappold International Sales Ag
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Publication date
Application filed by Rappold International Sales Ag filed Critical Rappold International Sales Ag
Publication of WO1998021009A1 publication Critical patent/WO1998021009A1/en

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Classifications

    • 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
    • B24D3/02—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent
    • B24D3/04—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent and being essentially inorganic
    • B24D3/14—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent and being essentially inorganic ceramic, i.e. vitrified bondings
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D18/00—Manufacture of grinding tools or other grinding devices, e.g. wheels, not otherwise provided for

Definitions

  • the invention relates to grinding wheels, in particular grinding wheels, made of sintered ceramic.
  • ceramic-bonded grinding wheels are either made from uniform, homogeneous grinding wheel masses or consist of several different masses, in which the grain type, grain size, bond type and fillers can vary.
  • the basic bodies produced in this way then undergo a sintering process before being used as a finished product.
  • each grinding wheel is an individual.
  • the subject of the present invention is the realization of the idea of also using prefabricated elements in the sintered ceramic sector, so that e.g. Different grinding rings can be formed on a prefabricated central part of a grinding wheel, so that the same type of central part can be used for grinding wheel series with completely different purposes and consequently different structures, which is usually irrelevant if the mechanical strength of the central part is higher or the same like that of the periphery.
  • sintered ceramic abrasives are classified according to FEPA and / or ⁇ NORM EN 12413 according to the following criteria:
  • A corundum
  • C silicon carbide
  • Z zirconium corundum
  • Grain size of the abrasive the numbers correspond to the mesh numbering: coarse: numbers from 4 to 24 medium: numbers from 30 to 60 fine: numbers from 70 to 220 very fine: numbers from 230 to 1200
  • Type of bond of the grinding wheel Here V means ceramic bonded.
  • the quality specification A 120 K7V for a grinding body is therefore: ceramic bonded (V), abrasive material: corundum (A), grain size (120) approximately in the middle of the "Fe ⁇ n” area, hardness of the grinding body in the border area of the "We ⁇ ch” area to the “medium” area, medium porosity.
  • the abrasive material is held together by the so-called bond, the proportion of which constitutes about 5 - 40% by weight of the abrasive body and which consists of 5 - 90% by weight frits, the rest being inorganic (mineral) fillers, e.g. Clay, and optionally up to about 8% by weight of metal oxides. Frits are premelted, artificial glass masses of the following compositions:
  • Residual elements 0 - 5% (Zr, Ba, Co, Ni)
  • the grinding body is a composite body in which at least one presintered element is sintered together with ceramic material.
  • the invention relates to composite ceramic abrasive bodies in which one or more abrasive body elements are present in the presintered state, which are connected to a further presintered abrasive element or to a raw ceramic material in such a way that, after a new sintering process or a hardening process corresponding to the joining material, a grinding unit unit again form, as well as the process for producing such abrasive bodies.
  • grinding wheel elements that are prefabricated are integrated into the manufacturing process. These prefabricated grinding wheel elements can form any section of the new grinding wheel, e.g. in the case of grinding wheels, the bore part, the peripheral part or an intermediate ring.
  • prefabricated grinding wheel elements can also be those which have already been in use, that is to say recycled constituents, which are connected or pressed with further pre-sintered grinding wheel elements or with a wide variety of grinding wheel masses and are thereby formed into new grinding wheels.
  • the grinding wheels are preferably grinding wheels and slip rings; this definition also covers coverings, but also grinding segments, grinding pins, grinding blocks, preferably all ISO-standardized grinding wheel shapes.
  • the invention relates to combinations of a presintered abrasive element and a part made of a new abrasive material which is applied to the presintered abrasive element.
  • the pre-sintered abrasive elements can contain corundum of all types and compositions, made of SiC, diamond, CBN (cubic boron nitride) and their combinations, as well as all sinterable inorganic base materials and have a wide variety of structures and hardnesses.
  • the possibility of using various hard materials such as, for example, carbides, nitrides, carbonitrides or silicides of metals, as well as all superhard silicates of natural origin or from synthetic production processes and ultimately also of special products such as tungsten or vanadates of rare earths or related substances is included.
  • various hard materials such as, for example, carbides, nitrides, carbonitrides or silicides of metals, as well as all superhard silicates of natural origin or from synthetic production processes and ultimately also of special products such as tungsten or vanadates of rare earths or related substances is included.
  • the assembly of the grinding wheel elements is carried out, for example, on the one hand by directly sintering ceramic masses onto the presintered grinding element or on the other hand by using primer systems which improve, facilitate or ensure the connection of individual elements.
  • Primers are sintering aids that form a binding phase when fired.
  • Ceramic primers are preferably used, which are essentially finely ground mixtures of glass-ceramic particles (glass frits, clay, feldspars, quartz substances). Ceramic foils can also be used to connect the abrasive elements.
  • a film casting slip which contains finely divided and well-dispersed ceramic formers and an organic binder and preferably a plasticizer is first worked into a thin layer and dried to form a flexible, so-called ceramic green film.
  • the slip can be a water slip, but also a slip with an organic solvent.
  • the organic fraction (usually 15-20% by weight) first "burns out” and the ceramic formers then sinter together to form a sintered connection layer with a melt phase.
  • This is eo ipso associated with a shrinkage, so that joining foils are particularly suitable if materials to be sintered or sintered workpieces can be joined together under pressure.
  • the decomposition products of the organic portion must diffuse essentially laterally out of the joining film layer, so that the heating according to the joining film technique must be carried out carefully in order to obtain a uniform, firm bond.
  • the grinding active part When sintering active grinding materials directly onto a pre-sintered grinding element, the grinding active part is e.g. simply pressed on.
  • an element with an increased binding component is manufactured (with a low-melting binding component), so that in the subsequent sintering process, the parts are optimally connected by melt flow.
  • connection variant in which the connection of the grinding wheel individual parts (pre-sintered and sintered-on element) is ensured by or in the presence of a primer, so that the grinding wheel elements are connected seamlessly and so firmly that they correspond at least to the strength value of a normally manufactured ceramic grinding wheel and all specifications as well legal requirements (national and international standards, requirement profiles of interest groups, etc.).
  • the invention has also proven to be particularly suitable for the production of ceramic-bonded diamond and CBN grinding wheels.
  • the pre-sintered abrasive elements By using the pre-sintered abrasive elements, the different dilatation behavior of the covering and the base body can be minimized, which also minimizes the risk of cracking and reproducible productions are also possible in the large diameter range.
  • This advantage also applies to all abrasive media that use other high-quality abrasives are brought, such as in particular boron carbides or nitrides or microcrystalline ceramic sintered corundum.
  • connection of the individual abrasive elements and the binding agent by which the elements are joined together is mainly because the connection of the grinding wheel elements must meet all technical, normative and safety requirements and regulations for ceramic grinding wheels. Therefore, the polymer must be formulated in such a way that it corresponds on the one hand to the binding elements of the presintered base body and can form a corresponding connection with them, but on the other hand must also be able to be integrated into the binding chemism of the grinding active composition. It must therefore be ensured that the glass ceramic body of the polymer which forms during the sintering process can be incorporated both into the structure of the presintered base body and into the structure of the sintered ceramic material.
  • foils are used to connect the abrasive elements (foils with a thickness of preferably approx. 0.1 to 0.5 mm but also thicker depending on the porosity of the surroundings of the foils), it must be ensured that the foil material is constructed similarly, like the ceramic elements to be joined.
  • connection zone It is important that the organic components of the film diffuse out of the connection zone during the sintering process in order to be able to exclude defects in the connection zone.
  • the average joining temperature for these foils is 1200 ° C.
  • the material of the film should be matched to the ceramic parts to be joined as far as possible, but usually has to sinter deeper.
  • the pre-sintered element was newly manufactured or whether it is an abrasive wheel that has already been used one or more times. If the pre-sintered abrasive element is a body that has not yet been used, it should only be subjected to mechanical pretreatment. After the dimensional accuracy has been established, the insert part is to be subjected to an interface treatment which ensures that it is free of impurities, dust or materials similar to release agents. Usually the interface is also profiled, which results in an even better connection with the ceramic material to be applied.
  • Previously used abrasive elements are normally contaminated with oils, greases, organic lubricants, coolants, cooling lubricants, metal and abrasive or abrasive sludges, etc. These contaminants must be eliminated quantitatively in order to guarantee a secure connection. This is achieved by subjecting the presintered element, preferably after producing the dimensional accuracy, depending on the type of contamination, to a washing, steaming, annealing, calibration or other chemical, physical or mechanical cleaning process. The part cleaned in this way must then be dried and then subjected to an interface treatment, or the new abrasive compound can be applied to the dry element.
  • a product-specific primer is applied to the interface of the pre-sintered and pretreated element by spraying, spreading or filling. It is important that the primer enters the pores of the interface and thus ensures that an optimal connection can take place during the sintering process.
  • the primer itself can be in liquid, pasty, but also solid, powdery form. In the case of liquid and pasty primers, the pretreated part of the grinding wheel is subjected to further drying; With solid, powdery primers treated blanks can be fed immediately to the pressing process.
  • the mold construction and pressing process also differs fundamentally from the current standard for the production of ceramic-bonded grinding wheels and is described in more detail for the production of grinding wheels.
  • it must be taken into account that in this case an already prefabricated, sintered grinding wheel element must be integrated into the mold.
  • bore punches, shaped rings and pressure plates must be designed in accordance with the final shape of the grinding wheel, taking into account the necessary oversize to comply with the specified end dimensions after the machining process of the sintered disc.
  • the presintered disc element lies absolutely flat on the base plate and is fixed in such a way that it cannot be moved. It is imperative in this pressing step that the edges match exactly between the shaped ring and the pre-sintered base element, since otherwise edge breaks or microcracks can occur during the pressing process, which will surely lead to rejection of the grinding wheel.
  • the next manufacturing criterion is filling the mold with ceramic mass. It should be noted that the mass must be added evenly than with standard filling processes and above all, the activated interfaces of the base body must not be affected by leveling aids such as combing or shearing devices.
  • the actual pressing process takes place after the press plate has been placed on top. This process is critical because the primer layer must not be pressed when pressing, otherwise the connection of the product zones cannot be ensured. This requirement is achieved by closing the press in one or more stages, the pressing process being carried out in the counterpressure process.
  • the last quality criterion in the pressing process is the ejection of the green body. Absolute flatness of the ejection elements is imperative because the smallest differences in level lead to different frictional loads on the circumference of the grinding body (outer surfaces), which cause stresses and ultimately cracks.
  • the interim storage of the green bodies should be as vibration-free as possible, as should their transport.
  • the green bodies When using liquid wetting agents, the green bodies have to go through a drying cycle before the actual sintering process.
  • the temperature curve to be driven must be flatter than standard curves and must be in the range around 60 ° C and at 90 ° C standing times so that escaping reaction or evaporation products can be easily removed via the microstructure capillaries.
  • this process step can be omitted.
  • the green bodies pretreated in this way are then placed on hollow corundum or related materials and fed to the sintering process.
  • the fire curves to be driven depend on the combination of the abrasive elements and differ from the standard curves primarily by several stopping points, preferably in the heating phase. Controlled cooling prevents residual stresses in the finished product.
  • the balance between heating speed and stopping points is a measure of the reproducibility and quality of the end products.
  • the finishing process differs from the finishing process in that the machining of the grinding wheel surfaces on both sides is to be carried out so evenly, that the pre-sintered disc part is subjected to little or no abrasion in order to use its original shape as unchanged as possible.
  • FIGS. 1-4 are views of radial grinding wheels; 5 is a partially broken oblique view of an axial grinding head and FIG. 6 is a partial view of an axial grinding ring.
  • equivalent components have the same reference symbols.
  • FIG. 1 is a view of a radial grinding wheel with a prefabricated, sintered hub part 1 with a clamping hole 2 and a sintered grinding ring 3, which is not prefabricated but is pressed in a form as a ceramic bulk material onto the hub part 1 and the green body thus obtained is sintered, sintering together with the hub part 1 takes place.
  • the hub part 1 is provided on its radial surface 4 with a primer layer 5, which enables this sintering together and thereby penetrates both into the hub part 1 and into the grinding ring 3, as can be seen on a larger scale in FIG. 2; the connection zone in hub part 1 is denoted by 1 'and in abrasive ring 3 by 3'.
  • the outer zone of the disk is not a grinding ring 3 sintered from ceramic bulk material, but rather a prefabricated sintered ceramic ring 6. This is an example where a recycled hub part can be provided with various newly prefabricated abrasive rings.
  • FIG. 4 as in FIGS. 1-3, an exemplary embodiment of a radial grinding wheel is shown, with the following special feature: in one form, a recycled hub part 1, which is primed on its radial outer surface, is centered with a clamping hole 2 and with a newly manufactured, sintered ceramic ring 7 that contains no abrasive material and is primed on both sides. Then the annular spaces 8, 9 between the hub part 1 and the ceramic ring 7 on the one hand and the ceramic ring 7 and the mold edge on the other filled with abrasive ring bulk material under pressure and the green body thus obtained is sintered together.
  • the sintering or sintering together can be carried out in any direction for the production of grinding wheels according to the invention, e.g. in the case of disks, the prefabricated sintered element can be arranged on the periphery, on the hub or in between, and also in several positions up to the extreme case that - as in FIG. 3 - all components are presintered and are only connected via the frit material.
  • sintered ceramic material bulk material is pressed for any zone of the abrasive body in a conventional manner and sintered after the heat treatment of the green body.
  • a special effect is not only given by e.g. Recycle cores from processed ceramic grinding media and provide them with grinding zones that differ from the core material, but also by prefabricating high-performance grinding rings with the most expensive abrasive equipment and then pressing and sintering them together with cheaper ceramic bulk material.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Ceramic Engineering (AREA)
  • Inorganic Chemistry (AREA)
  • Polishing Bodies And Polishing Tools (AREA)

Abstract

An abrasive body, in particular a grinding wheel, is made of sintered ceramics and characterised in that the abrasive body is a composite body with at least one previously sintered element sintered together with a ceramic material, in particular a not yet baked ceramic material. Also disclosed is a process for manufacturing this abrasive body.

Description

Schleifkörper und Verfahren zu dessen HerstellungAbrasive wheel and process for its manufacture
Die Erfindung betrifft Schleifkörper, insbesondere Schleifscheiben, aus Sinterkeramik.The invention relates to grinding wheels, in particular grinding wheels, made of sintered ceramic.
Nach dem Stand der Technik werden keramisch gebundene Schleifkörper entweder aus einheitlichen homogenen Schleifkörpermassen gefertigt oder bestehen aus mehreren unterschiedlichen Massen, bei denen Korntype, Korngröße, Bindungstype und Füllstoffe variieren können. Die so gefertigten Grundkörper durchlaufen anschließend einen Sintervorgang, ehe sie als Fertigprodukt zum Einsatz gelangen. Gemäß dieser Herstellungsweise ist jeder Schleifkörper ein Individuum. Gegenstand der vorliegenden Erfindung ist die Verwirklichung der Idee, auch auf dem Sinterkeramiksektor vorgefertigte Elemente zu verwenden, sodaß z.B. an einem vorgefertigten Zentralteil einer Schleifscheibe jeweils unterschiedliche Schleifkränze angeformt werden können, sodaß für Schleifscheibenserien völlig unterschiedlichen Anwendungszwecks und demzufolge unterschiedlichen Aufbaus jeweils der gleiche Zentralteiltyp verwendet werden kann, was regelmäßig dann gar keine Rolle spielt, wenn die mechanische Belastbarkeit des Zentralteils höher oder gleich groß ist wie die der Peripherie.According to the state of the art, ceramic-bonded grinding wheels are either made from uniform, homogeneous grinding wheel masses or consist of several different masses, in which the grain type, grain size, bond type and fillers can vary. The basic bodies produced in this way then undergo a sintering process before being used as a finished product. According to this method of manufacture, each grinding wheel is an individual. The subject of the present invention is the realization of the idea of also using prefabricated elements in the sintered ceramic sector, so that e.g. Different grinding rings can be formed on a prefabricated central part of a grinding wheel, so that the same type of central part can be used for grinding wheel series with completely different purposes and consequently different structures, which is usually irrelevant if the mechanical strength of the central part is higher or the same like that of the periphery.
Wie bekannt, werden sinterkeramische Schleifkörper nach FEPA und/oder nach der ÖNORM EN 12413 nach folgenden Kriterien klassifiziert:As is known, sintered ceramic abrasives are classified according to FEPA and / or ÖNORM EN 12413 according to the following criteria:
Art des Schleifmittels: A = Korund, C = Siliziumkarbid, Z = ZirkonkorundType of abrasive: A = corundum, C = silicon carbide, Z = zirconium corundum
Körnung des Schleifmittels: Die Zahlen entsprechen der Mesh-Numerierung: grob: Zahlen von 4 bis 24 mittel: Zahlen von 30 bis 60 fein: Zahlen von 70 bis 220 sehr fein: Zahlen von 230 bis 1200 Bindungsart des Schleifkorpers: Hier bedeutet V keramisch gebunden.Grain size of the abrasive: the numbers correspond to the mesh numbering: coarse: numbers from 4 to 24 medium: numbers from 30 to 60 fine: numbers from 70 to 220 very fine: numbers from 230 to 1200 Type of bond of the grinding wheel: Here V means ceramic bonded.
Härtegrad des Schleifkorpers:Degree of hardness of the grinding wheel:
A = extrem weich bis Z = extrem hart, wobeiA = extremely soft to Z = extremely hard, whereby
A - D = äußerst weichA - D = extremely soft
E - G = sehr weichE - G = very soft
H - K = weichH - K = soft
L - O = mittelL - O = medium
P - S - hartP - S - hard
T - W = sehr hartT - W = very hard
X - Z = äußerst hartX - Z = extremely hard
Gefuge (Struktur) des Schleifkorpers: ONORM Ziffern 0 - 14 (0 = dichtest, M = porosest ), FEPA Ziffern 0 - 20 (0 = dichtest, 20 = porosest)Structure (structure) of the grinding wheel: ONORM digits 0 - 14 (0 = densest, M = porous), FEPA digits 0 - 20 (0 = densest, 20 = porous)
Die Qualitatsangabe A 120 K7V für einen Schieifkorper heißt somit: keramisch gebunden (V), Abrasivmaterial: Korund (A), Körnung (120) etwa in der Mitte des "Feιn"-Bereιchs, Harte des Schleifkorpers im Grenzbereich des "Weιch"-Bereιchs zum 'Mιttel"-Bereιch, mittlere Porosität.The quality specification A 120 K7V for a grinding body is therefore: ceramic bonded (V), abrasive material: corundum (A), grain size (120) approximately in the middle of the "Feιn" area, hardness of the grinding body in the border area of the "Weιch" area to the "medium" area, medium porosity.
In sinterkeramischen Schleifkorpern ist das Abrasivmaterial durch die sogenannte Bindung zusammengehalten, deren Anteil etwa 5 - 40 Gew.% des Schleifkorpers bildet und die zu 5 - 90 Gew.% aus Fritten, Rest anorganische (mineralische) Füllstoffe, wie z.B. Ton, und gegebenenfalls bis zu etwa 8 Gew.% Metalloxide, bestehen. Fritten sind vorgeschmolzene, künstliche Glasmassen der folgenden Zusammensetzungen:In sintered ceramic abrasive particles, the abrasive material is held together by the so-called bond, the proportion of which constitutes about 5 - 40% by weight of the abrasive body and which consists of 5 - 90% by weight frits, the rest being inorganic (mineral) fillers, e.g. Clay, and optionally up to about 8% by weight of metal oxides. Frits are premelted, artificial glass masses of the following compositions:
Sι02 35 - 70 %Sι0 2 35 - 70%
B203 10 - 40 %B 2 0 3 10 - 40%
Na2Q 5 - 20 % κ2o 1 • - 20 %Na 2 Q 5 - 20% κ 2 o 1 • - 20%
Al203 0 - 1 5 %Al 2 0 3 0 - 1 5%
Fe203 0 - ■ 3 %Fe 2 0 3 0 - ■ 3%
Ti02 0 - • 5 %Ti0 2 0 - • 5%
ZnO 0 - ■ 10 %ZnO 0 - ■ 10%
CaO 0 - ■ 1 0 %CaO 0 - ■ 1 0%
MgO 0 - 10 %MgO 0-10%
Li20 0 - ■ 5 %Li 2 0 0 - ■ 5%
Restelemente 0 - 5 % (Zr, Ba, Co, Ni)Residual elements 0 - 5% (Zr, Ba, Co, Ni)
Erfindungsgemäß ist somit vorgesehen, daß der Schleifkörper ein Verbundkörper ist, bei dem zumindest ein vorgesintertes Element mit Keramikmaterial zusammengesintert ist.It is therefore provided according to the invention that the grinding body is a composite body in which at least one presintered element is sintered together with ceramic material.
Mit anderen Worten betrifft die Erfindung verbundkeramische Scheifkörper, bei denen ein oder mehrere Schleifkörperelemente im vorgesinterten Zustand vorliegen, welche mit einem weiteren vorgesinterten Schleifkörperelement oder mit einer Rohkeramikmasse so verbunden werden, daß diese nach einem neuerlichen Sinterprozeß bzw. einem der Verbindungsmasse entsprechenden Aushärteprozeß wieder eine Schleifkörpereinheit bilden, sowie das Verfahren zur Herstellung solcher Schleifkörper.In other words, the invention relates to composite ceramic abrasive bodies in which one or more abrasive body elements are present in the presintered state, which are connected to a further presintered abrasive element or to a raw ceramic material in such a way that, after a new sintering process or a hardening process corresponding to the joining material, a grinding unit unit again form, as well as the process for producing such abrasive bodies.
Dabei werden also in den Fertigungsprozeß Schleifkörperelemente integriert, die vorgefertigt sind. Diese vorgefertigten Schleifkörperelemente können jeden beliebigen Abschnitt des neuen Schleifkörpers bilden, z.B. bei Schleifscheiben den Bohrungsteil, den Peripherieteil oder einen Zwischenring.In this way, grinding wheel elements that are prefabricated are integrated into the manufacturing process. These prefabricated grinding wheel elements can form any section of the new grinding wheel, e.g. in the case of grinding wheels, the bore part, the peripheral part or an intermediate ring.
Diese vorgefertigten Schleifkörperelemente können auch solche sein, die bereits im Einsatz gestanden haben, also rezyklierte Bestandteile sind, die mit weiteren vorgesinterten Schleifkörperelementen oder mit unterschiedlichsten Schleifkörpermassen verbunden oder verpreßt und dadurch zu neuen Schleifkörpern geformt werden. Bei den Schleifkörpern handelt es sich vorzugsweise um Schleifscheiben und Schleifringe; es fallen unter diese Definition auch Beläge, aber auch Schleifsegmente, Schleifstifte, Schleifblöcke, vorzugsweise alle gemäß ISO-genormten Schleifkörperformen. Insbesondere betrifft die Erfindung Kombinationen aus einem vorgesinterten Schleifkörperelement und einem aus einer neuen schleifaktiven Masse gefertigten Schleifkörperteil, der auf das vorgesinterte Schleifkörperelement aufgebracht wird. Jedoch sind auch alle Kombinationen denkbar, wie beispielsweise der Einsatz von zwei oder mehreren vorgesinterten Schleifkörperelementen mit zwei oder mehreren neuen Schleifmasseelementen, die sowohl im Schleifkörperinnenteil wie auch an der Schleifkörperperipherie angeordnet sein können.These prefabricated grinding wheel elements can also be those which have already been in use, that is to say recycled constituents, which are connected or pressed with further pre-sintered grinding wheel elements or with a wide variety of grinding wheel masses and are thereby formed into new grinding wheels. The grinding wheels are preferably grinding wheels and slip rings; this definition also covers coverings, but also grinding segments, grinding pins, grinding blocks, preferably all ISO-standardized grinding wheel shapes. In particular, the invention relates to combinations of a presintered abrasive element and a part made of a new abrasive material which is applied to the presintered abrasive element. However, all combinations are also conceivable, such as the use of two or more pre-sintered grinding element elements with two or more new abrasive material elements, which can be arranged both in the inner part of the grinding wheel and on the periphery of the grinding wheel.
Die vorgesinterten Schleifkörperelemente können Korunde aller Art und jeder Zusammensetzung, aus SiC, Diamant, CBN (kubisches Bornitrid) und deren Kombinationen sowie alle sinterbaren anorganischen Grundmaterialien enthalten und unterschiedlichste Strukturen und Härten aufweisen.The pre-sintered abrasive elements can contain corundum of all types and compositions, made of SiC, diamond, CBN (cubic boron nitride) and their combinations, as well as all sinterable inorganic base materials and have a wide variety of structures and hardnesses.
Erfindungsgemäß ist auch die Möglichkeit des Einsatzes diverser Hartstoffe, wie beispielsweise von Carbiden, N itriden, Carbonitriden oder Siliciden von Metallen sowie aller hochharten Silikate natürlicher Herkunft oder aus synthetischen Herstellungsverfahren und letztlich auch von Sonderprodukten wie Wolframate oder Vanadate von seltenen Erden oder artverwandte Stoffe umfaßt.According to the invention, the possibility of using various hard materials, such as, for example, carbides, nitrides, carbonitrides or silicides of metals, as well as all superhard silicates of natural origin or from synthetic production processes and ultimately also of special products such as tungsten or vanadates of rare earths or related substances is included.
Das Zusammenfügen der Schleifkörperelemente erfolgt dabei z.B. einerseits durch direktes Aufsintern von Keramikmassen auf das vorgesinterte Schleifelement oder anderseits durch Anwendung von Primersystemen, die die Verbindung von Einzelelementen verbessern, erleichtern bzw. sicherstellen. Primer sind Sinterhilfen, die beim Brennen eine Bindephase bilden. Vorzugsweise werden keramische Primer eingesetzt, die im wesentlichen feingemahlene Gemische glaskeramischer Partikel sind (Glasfritten, Ton, Feldspäte, Quarzsubstanzen). Zur Verbindung der Schleifkörperelemente können aber auch keramische Folien angewendet werden. Bei der Fügefolientechnik wird zuerst ein Foliengießschlicker, der feinteilige und gut dispergierte Keramikbildner sowie einen organischen Binder und vorzugsweise einen Weichmacher enthält, zu einer dünnen Schicht geräkelt und diese zu einer flexiblen, sogenannten Keramik-Grünfolie getrocknet. Der Schlicker kann ein Wasserschi icker, aber auch ein Schlicker mit einem organischen Lösungsmittel sein.The assembly of the grinding wheel elements is carried out, for example, on the one hand by directly sintering ceramic masses onto the presintered grinding element or on the other hand by using primer systems which improve, facilitate or ensure the connection of individual elements. Primers are sintering aids that form a binding phase when fired. Ceramic primers are preferably used, which are essentially finely ground mixtures of glass-ceramic particles (glass frits, clay, feldspars, quartz substances). Ceramic foils can also be used to connect the abrasive elements. In the case of joining film technology, a film casting slip which contains finely divided and well-dispersed ceramic formers and an organic binder and preferably a plasticizer is first worked into a thin layer and dried to form a flexible, so-called ceramic green film. The slip can be a water slip, but also a slip with an organic solvent.
Beim Brennen einer derartigen Folie "brennt" zuerst der organische Anteil (meist 1 5-20 Gew.-%) aus und die Keramikbildner sintern dann unter Ausbildung einer Sinterverbindungsschicht mit Schmelzphase zusammen. Dies ist eo ipso mit einer Schwindung verbunden, sodaß sich Fügefolien vor allem dann eignen, wenn zu sinternde Werkstoffe oder gesinterte Werkstücke unter Druck zusammengefügt werden können. Weiters ist beim Zusammenfügen von Werkstücken zu bedenken, daß die Zersetzungsprodukte des organischen Anteils im wesentlichen lateral aus der Fügefolienschicht hinausdiffundieren müssen, das Aufheizen beim Verfahren gemäß der Fügefolientechnik also vorsichtig erfolgen muß, um eine gleichmäßige, feste Bindung zu erhalten.When a film of this type is fired, the organic fraction (usually 15-20% by weight) first "burns out" and the ceramic formers then sinter together to form a sintered connection layer with a melt phase. This is eo ipso associated with a shrinkage, so that joining foils are particularly suitable if materials to be sintered or sintered workpieces can be joined together under pressure. Furthermore, when assembling workpieces, it should be borne in mind that the decomposition products of the organic portion must diffuse essentially laterally out of the joining film layer, so that the heating according to the joining film technique must be carried out carefully in order to obtain a uniform, firm bond.
Beim direkten Aufsintern von schleifaktiven Massen auf ein vorgesintertes Schleifkörperelement wird der schleifaktive Teil z.B. einfach aufgepreßt. Vorzugsweise wird dabei ein Element mit erhöhtem Bindungsanteil gefertigt (mit niedrigschmelzendem Bindungsbestandteil), sodaß im folgenden Sinterprozeß eine optimale Verbindung der Teile durch Schmelzfluß erfolgt.When sintering active grinding materials directly onto a pre-sintered grinding element, the grinding active part is e.g. simply pressed on. Preferably, an element with an increased binding component is manufactured (with a low-melting binding component), so that in the subsequent sintering process, the parts are optimally connected by melt flow.
Es ist aber auch jene Verbindungsvariante vorgesehen, bei der die Verbindung der Schleifkörpereinzelteile (vorgesintertes und aufzusinterndes Element) durch bzw. in Anwesenheit eines Primers sichergestellt wird, sodaß die Schleifkörperelemente übergangslos und so fest verbunden werden, daß sie mindestens dem Festigkeitswert eines normal gefertigten Keramikschleifkörpers entsprechen und alle Vorgaben sowie gesetzliche Autlagen (nationale und internationale Normen, Anforderungsprofile von Interessengemeinschaften, etc.) erfüllen können.However, there is also the connection variant in which the connection of the grinding wheel individual parts (pre-sintered and sintered-on element) is ensured by or in the presence of a primer, so that the grinding wheel elements are connected seamlessly and so firmly that they correspond at least to the strength value of a normally manufactured ceramic grinding wheel and all specifications as well legal requirements (national and international standards, requirement profiles of interest groups, etc.).
Die Erfindung hat sich auch als besonders geeignet für die Herstellung keramisch gebundener Diamant- und CBN-Schleifscheiben erwiesen. Durch den Einsatz der vorgesinterten Schleifkorperelemente kann dabei das unterschiedliche Dilatationsverhalten von Belag und Grundkorper minimiert werden, wodurch auch die Gefahr der Rißbildung minimiert wird und auch im großen Durchmesserbereich reproduzierbare Produktionen möglich werden Dieser Vorteil gilt auch für alle Schleifkorper, bei denen sonstige hochwertige Schleifmittel zum Einsatz gebracht werden, wie insbesondere Borcarbide oder Nitride oder mikrokristalline keramische Sinterkorunde.The invention has also proven to be particularly suitable for the production of ceramic-bonded diamond and CBN grinding wheels. By using the pre-sintered abrasive elements, the different dilatation behavior of the covering and the base body can be minimized, which also minimizes the risk of cracking and reproducible productions are also possible in the large diameter range.This advantage also applies to all abrasive media that use other high-quality abrasives are brought, such as in particular boron carbides or nitrides or microcrystalline ceramic sintered corundum.
Wesentlich ist die Art der Verbindung der einzelnen Schleifkorperelemente sowie das Bindemittel, durch welches die Elemente aneinandergefügt werden. Dies vor allem deshalb, weil die Verbindung der Schleifkorperelemente allen technischen, normativen und sicherheitstechnischen Anforderungen und Vorschriften für Keramikschleifkorper entsprechen muß. Daher muß der Pπmer so rezeptiert sein, daß er einerseits den Bindungselementen der vorgesinterten Basiskorper entspricht und mit diesen eine entsprechende Verbindung eingehen kann, andererseits aber auch in den Bindungschemismus der schleifaktiven Masse integrierbar sein muß. Es ist also sicherzustellen, daß sich die beim Sinterprozeß bildenden Glaskeramikkorper des Pπmers sowohl in die Struktur des vorgesinterten Basiskorpers als auch in die Struktur des angesinterten Keramikmateπals eingebunden werden können.What is essential is the type of connection of the individual abrasive elements and the binding agent by which the elements are joined together. This is mainly because the connection of the grinding wheel elements must meet all technical, normative and safety requirements and regulations for ceramic grinding wheels. Therefore, the polymer must be formulated in such a way that it corresponds on the one hand to the binding elements of the presintered base body and can form a corresponding connection with them, but on the other hand must also be able to be integrated into the binding chemism of the grinding active composition. It must therefore be ensured that the glass ceramic body of the polymer which forms during the sintering process can be incorporated both into the structure of the presintered base body and into the structure of the sintered ceramic material.
Als Primer sind grundsätzlich alle glas- oder porzellanbildenden anorganischen Materialien vorgesehen, vorzugsweise werden dafür aber Fritten und jene Bindungs- mateπalien zum Einsatz kommen, welche inden Rezepturen der Bindungen eingesetzt wurden, aus denen die vorgesinterten Basiselemente bzw. die Keramikmassen gefertigt wurden Je nach Anwendungs- bzw. Einsatzbereich werden diese Primer vorzugsweise so auszulegen sein, daß ihr Schmelzpunkt knapp über oder unter dem der Bindung der Basiselemente liegt.Basically, all glass- or porcelain-forming inorganic materials are provided, but frits and the binding materials that were used in the formulations of the bonds from which the presintered basic elements or the ceramic materials were made are preferably used. These primers are preferred should be designed so that their melting point is just above or below that of the binding of the base elements.
Werden zur Verbindung der Schleifkorperelemente keramische Folien verwendet (Folien mit Stärken von vorzugsweise ca. 0,1 bis 0,5 mm aber auch dicker je nach der Porosität der Umgebung der Folien), so ist darauf zu achten, daß das Folienmaterial ähnlich aufgebaut ist, wie die zu fügenden Keramikelemente.If ceramic foils are used to connect the abrasive elements (foils with a thickness of preferably approx. 0.1 to 0.5 mm but also thicker depending on the porosity of the surroundings of the foils), it must be ensured that the foil material is constructed similarly, like the ceramic elements to be joined.
Wichtig ist, daß die organischen Bestandteile der Folie beim Sinterprozeß aus der Verbindungszone diffundieren, um Fehlstellen in der Verbindungszone ausschließen zu können. Die Fügetemperatur bei diesen Folien liegt im Schnitt bei 1200°C. Der Werkstoff der Folie soll materialmäßig möglichst an die zu verbindenden Keramikteile angepaßt sein, muß im Regelfall aber tiefer sintern.It is important that the organic components of the film diffuse out of the connection zone during the sintering process in order to be able to exclude defects in the connection zone. The average joining temperature for these foils is 1200 ° C. The material of the film should be matched to the ceramic parts to be joined as far as possible, but usually has to sinter deeper.
Optimale Verbindungen werden sichergestellt, wenn die zu fügenden Schleifmittelelemente leicht konisch ausgeführt sind, da durch den beim Zusammenfügen entstehenden Axialdruck die Folie an die Grenzflächen der Schleifkorperelemente angepreßt wird.Optimal connections are ensured if the abrasive elements to be joined are slightly conical, since the film is pressed against the interfaces of the abrasive body elements by the axial pressure that occurs when they are joined.
Die Herstellung von Schleifkörpern mit vorgesinterten Schleifkörperelementen unterscheidet sich wesentlich von den Herstellungsmethoden nach dem derzeitigen Stand der Technik. Dies vor allem deshalb, weil im Fertigungsprozeß bereits vorgefertigte Elemente, z.B. Scheibenelemente, integriert werden müssen, worauf bei herkömmlicher Fertigung nicht Rücksicht genommen werden muß. Dies macht es auch notwendig, daß Formwerkzeuge ebenso wie die Arbeitsparameter der Preß- und Sinterprozeß-teilschritte den neuen Gegebenheiten angepaßt werden müssen.The production of grinding wheels with pre-sintered grinding wheel elements differs significantly from the production methods according to the current state of the art. This is mainly because elements that are already prefabricated in the manufacturing process, e.g. Disc elements must be integrated, which does not have to be taken into account in conventional production. This also makes it necessary that molds as well as the working parameters of the pressing and sintering process steps have to be adapted to the new conditions.
Bei der Vorbehandlung ist zu unterscheiden, ob das vorgesinterte Element neu gefertigt wurde oder ob es sich dabei um einen Schleifkörper handelt, der bereits ein oder mehrere Male im Einsatz gestanden ist. Handelt es sich beim vorgesinterten Schleifkörperlement um einen noch nicht im Einsatz gewesenen Körper, so ist dieser ausschließlich einer mechanischen Vorbehandlung zu unterziehen. Der Einsatzteil ist hier nach Hestellung der Maßhaltigkeit einer Grenzflächenbearbeitung zu unterziehen, die sicherstellt, daß diese frei von Verunreinigungen, Staub oder trennmittelähnlichen Materialien ist. Meist wird die Grenzfläche auch profiliert, wodurch es zu einer noch besseren Verbindung mit der aufzubringenden Keramikmasse kommt.During the pretreatment, a distinction must be made as to whether the pre-sintered element was newly manufactured or whether it is an abrasive wheel that has already been used one or more times. If the pre-sintered abrasive element is a body that has not yet been used, it should only be subjected to mechanical pretreatment. After the dimensional accuracy has been established, the insert part is to be subjected to an interface treatment which ensures that it is free of impurities, dust or materials similar to release agents. Usually the interface is also profiled, which results in an even better connection with the ceramic material to be applied.
Vorbenutzte Schleifkorperelemente sind im Normalfall mit Ölen, Fetten, organischen Schmierstoffen, Kühlmitteln, Kühlschmierstoffen, Metall und Schleifmittel- bzw. Schleifgutschlämmen, etc., verunreinigt. Diese Verunreinigungen müssen, um eine sichere Verbindung gewährleiten zu können, quantitativ eliminiert werden. Dies wird dadurch erreicht, daß das vorgesinterte Element, vorzugsweise nach Herstellung der Maßhaltigkeit, je nach Art der Verunreinigung, einem Wasch-, Bedampfungs-, Ausglüh-, Abdreh- oder sonstigem chemischen, physikalischen oder mechanischen Reinigungsprozeß unterworfen wird. Der so gereinigte Teil ist anschließend zu trocknen und danach einer Grenzflächen-behandlung zu unterziehen bzw. kann auf das trockene Element die Aufbringung der neuen Schleifmittelmasse erfolgen.Previously used abrasive elements are normally contaminated with oils, greases, organic lubricants, coolants, cooling lubricants, metal and abrasive or abrasive sludges, etc. These contaminants must be eliminated quantitatively in order to guarantee a secure connection. This is achieved by subjecting the presintered element, preferably after producing the dimensional accuracy, depending on the type of contamination, to a washing, steaming, annealing, calibration or other chemical, physical or mechanical cleaning process. The part cleaned in this way must then be dried and then subjected to an interface treatment, or the new abrasive compound can be applied to the dry element.
Die Grenzflächenbehandlung, der Auftrag eines Primers auf diese und die Primerrezeptierung sind wesentliche Voraussetzung für eine sichere Verbindung der Schleifkörperteile. Dabei wird auf die Grenzfläche des vorgesinterten und vorbehandelten Elementes ein produktspezifischer Primer aufgebracht und zwar durch Aufspritzen, Aufstreichen oder Aufspachteln. Wichtig ist dabei, daß der Primer in die Poren der Grenzfläche eintritt und damit sicherstellt, daß beim Sinterprozeß eine optimale Verbindung erfolgen kann. Der Primer selbst kann dabei in flüssiger, pastöser, aber auch fester, pulverförmiger Form vorliegen. Bei flüssigen und pastösen Primern wird der vorbehandelte Schleifkörperteil einer weiteren Trocknung unterzogen; mit festen, pulverförmigen Primern behandelte Rohlinge können sofort dem Preßprozeß zugeführt werden.The interface treatment, the application of a primer to it and the primer formulation are essential prerequisites for a secure connection of the grinding wheel parts. A product-specific primer is applied to the interface of the pre-sintered and pretreated element by spraying, spreading or filling. It is important that the primer enters the pores of the interface and thus ensures that an optimal connection can take place during the sintering process. The primer itself can be in liquid, pasty, but also solid, powdery form. In the case of liquid and pasty primers, the pretreated part of the grinding wheel is subjected to further drying; With solid, powdery primers treated blanks can be fed immediately to the pressing process.
Der Formenaufbau- und Preßprozeß unterscheidet sich ebenfalls grundlegend vom heutigen Standard der Herstellung keramisch gebundener Schleifkörper und wird für die Herstellung von Schleifscheiben näher beschrieben. Schon beim Aufbau der Preßform ist zu berücksichtigen, daß in diesem Fall ein bereits vorgefertigtes, gesintertes Schleifscheibenelement in die Form integriert werden muß. Aus diesem Grund sind Bohrungsstempel, Formringe und Preßplatten entsprechend der Endform des Schleifkörpers auszulegen, unter Berücksichtigung notwendiger Übermaße zur Einhaltung vorgegebener Endmaße nach dem Bearbeitungsprozeß der gesinterten Scheibe. Ebenso ist sicherzustellen, daß das vorgesinterte Scheibenelement absolut plan auf der Grundplatte aufliegt und so fixiert wird, daß ein Verschieben desselben ausgeschlossen ist. Zwingend ist bei dieser Prezeßstufe auch die exakte Kantenübereinstimmung zwischen Formring und vorgesintertem Basiselement, da anderenfalls beim Preßvorgang Kantenbrüche oder Mikrorisse entstehen können, die mit Sicherheit zum Ausschuß des Schleifkörpers führen.The mold construction and pressing process also differs fundamentally from the current standard for the production of ceramic-bonded grinding wheels and is described in more detail for the production of grinding wheels. When setting up the mold, it must be taken into account that in this case an already prefabricated, sintered grinding wheel element must be integrated into the mold. For this reason, bore punches, shaped rings and pressure plates must be designed in accordance with the final shape of the grinding wheel, taking into account the necessary oversize to comply with the specified end dimensions after the machining process of the sintered disc. It must also be ensured that the presintered disc element lies absolutely flat on the base plate and is fixed in such a way that it cannot be moved. It is imperative in this pressing step that the edges match exactly between the shaped ring and the pre-sintered base element, since otherwise edge breaks or microcracks can occur during the pressing process, which will surely lead to rejection of the grinding wheel.
Als nächstes Herstellungskriterium ist die Formbefüllung mit Keramikmasse zu sehen. Dabei ist zu beachten, daß der Masseeintrag noch gleichmäßiger erfolgen muß als bei Standardfüllvorgängen und vor allem dürfen durch Planierhilfen, wie Kämm- oder Schereinrichtungen die aktivierten Grenzflächen des Basiskörpers nicht in Mitleidenschaft gezogen werden.The next manufacturing criterion is filling the mold with ceramic mass. It should be noted that the mass must be added evenly than with standard filling processes and above all, the activated interfaces of the base body must not be affected by leveling aids such as combing or shearing devices.
Ist die Masse homogen und unwuchtfrei verteilt, erfolgt nach Auflage der Preßplatte der eigentliche Preßvorgang. Dieser Vorgang ist deshalb kritisch, weil es beim Verpressen nicht zum Abdrücken der Primerauflage kommen darf, da sonst die Verbindung der Produktzonen nicht sichergestellt werden kann. Erreicht wird diese Forderung durch ein oder mehrstufiges Schließen der Presse, wobei der Preßvorgang im Gegendruckverfahren geführt wird. Letztes Qualitätskriterium beim Preßvorgang ist das Ausstoßen des Grünkörpers. Absolute Ebenflächigkeit der Ausstoßelemente ist deshalb zwingend, weil kleinste Niveauunterschiede zu unterschiedlichen Reibungsbelastungen am Schleifköperumfang (Außenflächen) führen, die Spannungszustände und letztlich Risse verursachen.If the mass is homogeneous and unbalanced, the actual pressing process takes place after the press plate has been placed on top. This process is critical because the primer layer must not be pressed when pressing, otherwise the connection of the product zones cannot be ensured. This requirement is achieved by closing the press in one or more stages, the pressing process being carried out in the counterpressure process. The last quality criterion in the pressing process is the ejection of the green body. Absolute flatness of the ejection elements is imperative because the smallest differences in level lead to different frictional loads on the circumference of the grinding body (outer surfaces), which cause stresses and ultimately cracks.
Die Zwischenlagerung der Grünkörper soll möglichst vibrationsfrei erfolgen, ebenso deren Transport.The interim storage of the green bodies should be as vibration-free as possible, as should their transport.
Die Grünkörper müssen beim Einsatz flüssiger Benetzungsmittel vor dem eigentlichen Sinterprozeß einen Trocknungszyklus durchlaufen. Die dabei zu fahrende Temperaturkurve ist gegenüber Standardkurven flacher anzulegen und muß im Bereich um 60°C sowie bei 90°C Stehzeiten enthalten, um entweichende Reaktions- bzw. Verdampfungsprodukte problemlos über die Gefügekapillaren abführen zu können. Beim Einsatz organischer Netzmittel, insbesonders wachsartiger Substanzen kann dieser Verfahrensschritt unterbleiben.When using liquid wetting agents, the green bodies have to go through a drying cycle before the actual sintering process. The temperature curve to be driven must be flatter than standard curves and must be in the range around 60 ° C and at 90 ° C standing times so that escaping reaction or evaporation products can be easily removed via the microstructure capillaries. When using organic wetting agents, especially wax-like substances, this process step can be omitted.
Die so vorbehandelten Grünkörper werden danach auf Hohlkugelkorund oder verwandten Materialien gesetzt und dem Sinterprozeß zugeführt. Die zu fahrenden Brandkurven sind abhängig von der Kombination der Schleifkorperelemente und unterscheiden sich von den Standardkurven vor allem durch mehrere Haltepunkte vorzugsweise in der Aufheizphase. Kontrolliertes Abkühlen verhindert Restspannungen im Fertigprodukt.The green bodies pretreated in this way are then placed on hollow corundum or related materials and fed to the sintering process. The fire curves to be driven depend on the combination of the abrasive elements and differ from the standard curves primarily by several stopping points, preferably in the heating phase. Controlled cooling prevents residual stresses in the finished product.
Die Ausgewogenheit zwischen Aufheizgeschwindigkeit und Haltepunkten sind ein Maß für die Reproduzierbarkeit und Qualität der Endprodukte.The balance between heating speed and stopping points is a measure of the reproducibility and quality of the end products.
Die Endbearbeitung unterscheidet sich von der Endbearbeitung dadurch, daß die beidseitige Bearbeitung der Schleifkörperflächen derart gleichmäßig auszuführen ist, daß der vorgesinterte Scheibenteil keinem oder nur geringem Abrieb unterzogen wird, um seine ursprüngliche Gestalt möglichst unverändert zu nutzen.The finishing process differs from the finishing process in that the machining of the grinding wheel surfaces on both sides is to be carried out so evenly, that the pre-sintered disc part is subjected to little or no abrasion in order to use its original shape as unchanged as possible.
Die Erfindung wird nachfolgend unter Bezugnahme auf die Zeichnung näher beschrieben, in der die Fig.1 - 4 Ansichten von Radialschleifscheiben sind; die Fig.5 ist eine teilweise weggebrochene Schrägansicht eines Axialschleifkopfes und die Fig.6 eine Teilansicht eines Axialschleifrings. In der Zeichnung haben äquivalente Bauteile gleiche Bezugszeichen.The invention is described in more detail below with reference to the drawing, in which FIGS. 1-4 are views of radial grinding wheels; 5 is a partially broken oblique view of an axial grinding head and FIG. 6 is a partial view of an axial grinding ring. In the drawing, equivalent components have the same reference symbols.
Fig.1 ist eine Ansicht einer Radialschleifscheibe mit einem vorgefertigten, gesinterten Nabenteil 1 mit Aufspannloch 2 und einem angesinterten Schleifkranz 3, der nicht vorgefertigt ist, sondern in einer Form als Keramikschüttmasse an den Nabenteil 1 angepreßt und der so erhaltene Grünkörper gesintert wird, wobei Zusammensintern mit dem Nabenteil 1 stattfindet. Der Nabenteil 1 ist an seiner Radialfläche 4 mit einer Primerschicht 5 versehen, die dieses Zusammensintern ermöglicht und dabei sowohl in den Nabenteil 1 als auch in den Schleifkranz 3 eindringt, wie dies in Fig.2 in größerem Maßstab zu erkennen ist; dabei ist die Verbindungszone im Nabenteil 1 mit 1 ' und im Schleifkranz 3 mit 3' bezeichnet.1 is a view of a radial grinding wheel with a prefabricated, sintered hub part 1 with a clamping hole 2 and a sintered grinding ring 3, which is not prefabricated but is pressed in a form as a ceramic bulk material onto the hub part 1 and the green body thus obtained is sintered, sintering together with the hub part 1 takes place. The hub part 1 is provided on its radial surface 4 with a primer layer 5, which enables this sintering together and thereby penetrates both into the hub part 1 and into the grinding ring 3, as can be seen on a larger scale in FIG. 2; the connection zone in hub part 1 is denoted by 1 'and in abrasive ring 3 by 3'.
Beim Ausführungsbeispiel nach Fig.3 ist die Außenzone der Scheibe kein aus Keramikschüttgut angesinterter Schleifkranz 3, sondern ein vorgefertigter gesinterter Keramikring 6. Dies ist ein Beispiel, wo ein rezyklierter Nabenteil mit verschiedenen neu vorgefertigten Abrasivringen versehen werden kann.In the exemplary embodiment according to FIG. 3, the outer zone of the disk is not a grinding ring 3 sintered from ceramic bulk material, but rather a prefabricated sintered ceramic ring 6. This is an example where a recycled hub part can be provided with various newly prefabricated abrasive rings.
In Fig.4 ist wie in den Fig. 1 - 3 ein Ausführungsbeispiel einer Radialschleifscheibe gezeigt, mit folgender Besonderheit: In einer Form wird ein recyklierter, an seiner radialen Außenfläche geprimter Nabenteil 1 mit Aufspannloch 2 zentriert sowie mit einem neu gefertigten, gesinterten Keramikring 7 umlegt, der kein Abrasivmaterial enthält und beidseits geprimt wird. Sodann werden die Ringräume 8,9 zwischen einerseits Nabenteil 1 und Keramikring 7 und anderseits Keramikring 7 und Formrand mit Schleifkranzschüttgut unter Druck gefüllt und der so erhaltene Grünkörper zusammengesintert.In FIG. 4, as in FIGS. 1-3, an exemplary embodiment of a radial grinding wheel is shown, with the following special feature: in one form, a recycled hub part 1, which is primed on its radial outer surface, is centered with a clamping hole 2 and with a newly manufactured, sintered ceramic ring 7 that contains no abrasive material and is primed on both sides. Then the annular spaces 8, 9 between the hub part 1 and the ceramic ring 7 on the one hand and the ceramic ring 7 and the mold edge on the other filled with abrasive ring bulk material under pressure and the green body thus obtained is sintered together.
Die Fig. 5 und 6 bedürfen keiner Erläuterung.5 and 6 require no explanation.
Grundsätzlich kann das Zusammensintern bzw. Ansintern zur Herstellung von erfindungsgemäßen Schleifkörpern in jede Richtung erfolgen, also z.B. bei Scheiben das vorgefertigte Sinterelement an der Peripherie, an der Nabe oder dazwischen angeordnet sein, sowie auch an mehreren Positionen bis hin zum Extremfall, daß - wie gemäß Fig.3 - alle Bestandteile vorgesintert sind und lediglich über das Frittenmaterial verbunden werden. In der Regel wird jedoch für irgendeine Zone des Schleifkörpers angesintertes Keramikmaterialschüttgut auf herkömmliche Weise verpreßt und nach der Wärmebehandlung des Grünkörpers gesintert.Basically, the sintering or sintering together can be carried out in any direction for the production of grinding wheels according to the invention, e.g. in the case of disks, the prefabricated sintered element can be arranged on the periphery, on the hub or in between, and also in several positions up to the extreme case that - as in FIG. 3 - all components are presintered and are only connected via the frit material. As a rule, however, sintered ceramic material bulk material is pressed for any zone of the abrasive body in a conventional manner and sintered after the heat treatment of the green body.
Ein besonderer Effekt ist nicht nur dadurch gegeben, daß man z.B. Kerne von abgearbeiteten Keramikschleifkörpern recyklieren und mit vom Kernmaterial verschiedenen Schleifzonen versehen kann, sondern auch dadurch, daß man Hochleistungschleifkränze mit teuersten Abrasivbestückungen vorfertigen und dann mit billigeren Keramikschüttmaterial verpressen und zusammensintern kann. A special effect is not only given by e.g. Recycle cores from processed ceramic grinding media and provide them with grinding zones that differ from the core material, but also by prefabricating high-performance grinding rings with the most expensive abrasive equipment and then pressing and sintering them together with cheaper ceramic bulk material.

Claims

Patentansprüche: Claims:
1 . Schleifkörper, insbesondere Schleifscheibe, aus Sinterglaskeramik, dadurch gekennzeichnet, daß der Schleifkörper ein Verbundkörper ist, bei dem zumindest ein vorgesintertes Element mit Glaskeramikmaterial zusammengesintert ist.1 . Grinding body, in particular grinding wheel, made of sintered glass ceramic, characterized in that the grinding body is a composite body in which at least one presintered element is sintered together with glass ceramic material.
2. Schleifkörper nach Anspruch 1 , dadurch gekennzeichnet, daß zumindest ein vorgesintertes Element ein rezyklierter Bestandteil ist.2. Abrasive body according to claim 1, characterized in that at least one presintered element is a recycled component.
3. Schleifkörper nach Anspruch 2, dadurch gekennzeichnet, daß zumindest ein vorgesintertes Element ein rezyklierter Bestandteil eines Vorgängerschleifkörpers ist.3. Abrasive body according to claim 2, characterized in that at least one presintered element is a recycled component of a previous abrasive body.
4. Schleifkörper nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß zumindest ein vorgesintertes Element direkt mit Glaskeramikmaterial zusammengesintert ist.4. Abrasive body according to one of claims 1 to 3, characterized in that at least one presintered element is sintered directly with glass ceramic material.
5. Schleifkörper nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß zumindest ein vorgesintertes Element über eine Sinterhilfe mit Glaskeramikmaterial zusammengesintert ist.5. Abrasive body according to one of claims 1 to 3, characterized in that at least one presintered element is sintered together with a glass ceramic material via a sintering aid.
6. Schleifkörper nach Anspruch 5, dadurch gekennzeichnet, daß die Sinterhilfe ein glasbildendes Material ist.6. Abrasive body according to claim 5, characterized in that the sintering aid is a glass-forming material.
7. Schleifkörper nach einem der Ansprüche 1 bis 6, dadurch gekennzeichnet, daß das Keramikmaterial vorgesintert ist.7. Abrasive body according to one of claims 1 to 6, characterized in that the ceramic material is presintered.
8. Verfahren zur Herstellung eines Schleifkörpers nach einem der Ansprüche 1 bis 7, dadurch gekennzeichnet, daß zumindest ein vorgesintertes Element in einer Form mit Keramikmaterial zu einem Schleifkörper ergänzt und der Schleifkörper anschließend zusammengesintert wird.8. A method for producing an abrasive body according to one of claims 1 to 7, characterized in that at least one pre-sintered element in a mold Ceramic material added to a grinding wheel and the grinding wheel is then sintered together.
9. Verfahren nach Anspruch 8, dadurch gekennzeichnet, daß das vorgesinterte Element vor dem Ergänzen mit einer Sinterhilfe oberflächenbehandelt wird.9. The method according to claim 8, characterized in that the presintered element is surface-treated before being supplemented with a sintering aid.
10. Verfahren nach Anspruch 8, dadurch gekennzeichnet, daß das vorgesinterte Element durch keramische Folien verbunden wird. 10. The method according to claim 8, characterized in that the presintered element is connected by ceramic foils.
PCT/AT1997/000244 1996-11-13 1997-11-10 Abrasive body and process for manufacturing the same WO1998021009A1 (en)

Applications Claiming Priority (2)

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ATA1987/96 1996-11-13
AT198796 1996-11-13

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1362671A1 (en) * 2002-05-15 2003-11-19 SAINT-GOBAIN Diamantwerkzeuge GmbH & Co. KG Method for the production of free-sintered ring-shaped abrasive lining for grinding wheels
JP2018534166A (en) * 2015-11-09 2018-11-22 センター フォア アブラシブズ アンド リフラクトリーズ リサーチ アンド ディベロップメント ツェー アー エァ エァ デー ゲゼルシャフト ミット ベシュレンクテル ハフツング Sintered ceramic polishing element having a polycrystalline and flat geometric structure, method of manufacture and use thereof

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6311283A (en) * 1986-07-01 1988-01-18 Daido Sangyo Kk Diamond wheel and formation thereof
JPH0265974A (en) * 1988-08-29 1990-03-06 Noritake Co Ltd Super abrasive grain vitrified grindstone having ceramic sintered holding body part
DE4446591A1 (en) * 1994-12-24 1996-06-27 Schleifmittel Werk Karl Seiffe Recyclable grinding wheel zones

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6311283A (en) * 1986-07-01 1988-01-18 Daido Sangyo Kk Diamond wheel and formation thereof
JPH0265974A (en) * 1988-08-29 1990-03-06 Noritake Co Ltd Super abrasive grain vitrified grindstone having ceramic sintered holding body part
DE4446591A1 (en) * 1994-12-24 1996-06-27 Schleifmittel Werk Karl Seiffe Recyclable grinding wheel zones

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* Cited by examiner, † Cited by third party
Title
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DATABASE WPI Section Ch Week 9015, Derwent World Patents Index; Class LP, AN 90-113386 (25) *
PATENT ABSTRACTS OF JAPAN vol. 12, no. 208 (M - 709) 15 June 1988 (1988-06-15) *
PATENT ABSTRACTS OF JAPAN vol. 14, no. 243 (M - 0977) 23 May 1990 (1990-05-23) *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1362671A1 (en) * 2002-05-15 2003-11-19 SAINT-GOBAIN Diamantwerkzeuge GmbH & Co. KG Method for the production of free-sintered ring-shaped abrasive lining for grinding wheels
JP2018534166A (en) * 2015-11-09 2018-11-22 センター フォア アブラシブズ アンド リフラクトリーズ リサーチ アンド ディベロップメント ツェー アー エァ エァ デー ゲゼルシャフト ミット ベシュレンクテル ハフツング Sintered ceramic polishing element having a polycrystalline and flat geometric structure, method of manufacture and use thereof

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