WO2016010226A1 - Cermet and method for preparing same - Google Patents

Cermet and method for preparing same Download PDF

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Publication number
WO2016010226A1
WO2016010226A1 PCT/KR2015/002161 KR2015002161W WO2016010226A1 WO 2016010226 A1 WO2016010226 A1 WO 2016010226A1 KR 2015002161 W KR2015002161 W KR 2015002161W WO 2016010226 A1 WO2016010226 A1 WO 2016010226A1
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Prior art keywords
cermet
titanium
carbon
weight
based material
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PCT/KR2015/002161
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French (fr)
Korean (ko)
Inventor
송명훈
홍순형
이원혁
류호진
신영민
이준호
황금철
Original Assignee
주식회사 대화알로이테크
한국과학기술원
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Publication of WO2016010226A1 publication Critical patent/WO2016010226A1/en

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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C29/00—Alloys based on carbides, oxides, nitrides, borides, or silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides, sulfides

Definitions

  • the present invention relates to a cermet and a method for producing the same.
  • Cermet is a compound word of ceramic and metal, and metal and alloy are matrix in a wide range, and it includes ceramic particles, which have the advantages of metal and ceramic. .
  • the cermet material is distinguished from cemented carbide, which is the most widely used for cutting tool systems in manufacturing. Compared to cemented carbides in the prior art, there was a limitation in application due to the significantly lower strength and toughness.In order to solve this problem, an improved cermet was developed to increase the matrix content and compensate the decrease of hardness by strengthening the heat treatment on the matrix. It became.
  • the improved cermet is manufactured by mixing the ceramic particle powder with individual elemenet or alloyed powder and then forming sintering step. The abrasion resistance and toughness vary greatly depending on the manufacturing conditions.
  • the size of the product that can be manufactured because sintering is performed under conditions in which the matrix phase is changed into a liquid phase for sufficient wet of the matrix phase.
  • the cermet is manufactured in the form of a casting form and a desired product in the form of a pre-form having a large porosity, and the base alloy is made into a liquid form.
  • powder metallurgy demands high cost due to high base metal price and difficult machining, simple product shape, limited size, complicated stage, and high investment equipment cost compared to liquid phase. There is this.
  • the melt pressure impregnation method is capable of manufacturing large and near-net composites, and enables the design and cutting of characteristics by inclining the center and surface of the composite material, and the simple steps by the pressure impregnation step of the molten metal, and low cost.
  • each step has advantages and disadvantages, it is required to have excellent mechanical properties (tensile, compressive, abrasion, fatigue, creep, etc.) at room temperature and high temperature due to the excellent interfacial properties between the matrix and the formed reinforcement phase when manufacturing the metal composite material.
  • the present invention is to solve the problems of the related art, it is an object of the present invention to provide a cermet excellent in the mechanical properties at room temperature and high temperature because of the excellent interfacial properties between the base alloy and the formed reinforcement phase and its manufacturing method.
  • another object of the present invention is to produce a metal composite material at a low temperature (soaking temperature), significantly improving the life of the equipment installation step, less shape deformation during the manufacture of large products, the cermet that can significantly reduce material loss And a method for producing the same.
  • the carbon-based material Titanium-based materials; And an alloy base including at least one selected from the group consisting of Fe, Ni, Mo, Cr, Si, Mn, and Cu.
  • the carbon-based material and the titanium-based material may form a reinforcing phase including titanium carbide (TiC).
  • the reinforcing phase may include titanium carbide (TiC) formed by an in-situ reaction in the alloy matrix.
  • TiC titanium carbide
  • the reinforcing phase may have a particle size of 1.0 ⁇ m to 50 ⁇ m.
  • the reinforcement phase may be spherical.
  • the carbon-based material the group consisting of graphite, graphene, carbon black, diamond, diamond like carbon (DLC), fullerene (fullerene, C60), carbon fiber, carbon nanorods and carbon nanotubes (CNT) It may be to include at least one selected from.
  • the titanium-based material is at least one selected from the group consisting of iron titanium (FeTi), manganese titanium (MnTi), barium titanium (BaTi), strontium titanium (SrTi), nickel titanium (NiTi) and cobalt titanium (CoTi). It may be to include.
  • the mixing ratio of the carbon-based material / the titanium-based material may be 0.25 to 3.0.
  • the carbonaceous material in the cermet may be 0.5% to 5.0% by weight.
  • the alloy base may include a tool steel system including at least one selected from the group consisting of Fe, STD 11, STD 61, SKH 2 and SKH 9; Or STS 430, STS 409, STS410, STS 440 (C), and STS 630 (17-4PH) may include a stainless alloy including at least one or more selected from the group consisting of.
  • the alloy base containing Fe is 3% by weight to 25% by weight of chromium (Cr), more than 0% by weight of nickel (Ni), 5% by weight or less, and 0.1% by weight of silicon (Si) in the alloy base containing Fe.
  • Cr chromium
  • Ni nickel
  • Si silicon
  • the reinforcing phase and the alloy base may be consistent.
  • the cermet may be one having a relative density of 90% or more.
  • a second aspect of the present invention provides a method for mixing a carbonaceous material, a titanium-based material and an alloy base including at least one metal selected from the group consisting of Fe, Ni, Mo, Cr, Si Mn, and Cu; Grinding the mixture; Compacting the ground mixture; And in-situ reaction sintering the molded product, which may include a method of manufacturing a cermet.
  • the in situ reaction sintering step may be to maintain for 0.5 hours to 24 hours in the temperature range of 1100 °C to 1400 °C and pressure range of 1 ⁇ 10 -3 Torr to 1 ⁇ 10 1 Torr.
  • the carbon-based material and the titanium-based material may be to form a reinforcement phase including TiC.
  • the reinforcing phase may have a particle size of 1.0 ⁇ m to 50 ⁇ m.
  • the reinforcement phase may be spherical.
  • the reinforcing phase and the alloy base may be consistent.
  • the cermet according to the present invention and a method for manufacturing the same are capable of mass-producing a cermet produced by in-situ reaction of a ceramic-reinforced phase (TiC) in an alloy matrix phase at a low cost, and interfacial properties between the matrix alloy and the formed reinforced phase
  • TiC ceramic-reinforced phase
  • the excellent cermet can be manufactured at room temperature and high temperature with excellent mechanical properties such as tension, compression, wear, fatigue, creep, and the like. It can proceed at a much lower temperature than the conventional sintering step, thereby providing excellent equipment life and shape stability of the cermet, and excellent wear resistance and strength.
  • FIG. 1 is a flow chart of a method for manufacturing a cermet according to an embodiment of the present invention.
  • the cermet according to the first aspect of the invention the carbon-based material; Titanium-based materials; And an alloy base including at least one selected from the group consisting of Fe, Ni, Mo, Cr, Si, Mn, and Cu.
  • the cermet according to an embodiment of the present invention may be a carbon-based material and the titanium-based material may form a reinforcing phase including titanium carbide (TiC). Therefore, the interfacial properties between the alloy base and the formed reinforcement phase are excellent, and mechanical properties such as tensile, compression, wear, fatigue, creep, etc. at room temperature and high temperature are excellent, and existing in liquid or semi-liquid base conditions. Compared with the sintering method, it has a high density even in a low solid state region.
  • TiC titanium carbide
  • the reinforcing phase may include titanium carbide (TiC) formed by an in-situ reaction in the alloy matrix.
  • TiC titanium carbide
  • the cermet according to an embodiment of the present invention can be manufactured in a manner that combines the advantages of the powder metallurgy step and the in-situ casting step, thereby significantly improving the life of the step equipment, the existing sintering step when manufacturing a large product There is less shape deformation, and material loss can be greatly reduced.
  • the reinforcing phase may have a particle size of 1.0 ⁇ m to 50 ⁇ m. If the particle size of the reinforcing phase is less than 1.0 ⁇ m, a relatively large number of matrix alloys may cause a binder phase aggregation, and if the particle size exceeds 50 ⁇ m, the wettability of the matrix alloy against the reinforcing phase may be lowered, leading to a lower toughness. As the interparticle distance increases, particle precipitation and dispersion strengthening effects (Orowan strengthening) may decrease.
  • the reinforcement phase may be spherical.
  • the surface area is small and can support higher applied stress, which has better mechanical properties, resulting in delayed dislocation movement during crack propagation and material deformation at high temperatures and reduced crack formation potential. Will have an impact.
  • the carbon-based material the group consisting of graphite, graphene, carbon black, diamond, diamond like carbon (DLC), fullerene (fullerene, C60), carbon fiber, carbon nanorods and carbon nanotubes (CNT) It may include at least one selected from, but is not limited thereto.
  • the titanium-based material is at least one selected from the group consisting of iron titanium (FeTi), manganese titanium (MnTi), barium titanium (BaTi), strontium titanium (SrTi), nickel titanium (NiTi) and cobalt titanium (CoTi). It may be to include, but is not limited thereto.
  • the mixing ratio of the carbon-based material / the titanium-based material may be 0.25 to 3.0.
  • the mixing ratio of the carbonaceous material / titanium material is less than 0.25, residual Ti, which does not form carbide, remains in the base alloy in oxide form and acts as inclusions to significantly lower the low temperature and high temperature properties. And, if it is more than 3.0, there may be a problem such that the sintered stability is impaired by remaining in the base alloy of excess carbon not participating in the reaction, and the manufactured sintered body also has brittleness.
  • the carbonaceous material in the cermet may be 0.5% to 5.0% by weight. If the carbonaceous material is less than 0.5% by weight, it is difficult to obtain a dense and compact sintered body with the above-mentioned problems due to the Ti residue not participating in the reaction, and if it is more than 5.0% by weight, it is local due to the residual in the base alloy of excess carbon. As a result of the significant melting, the sintering stability is lowered, including a phenomenon in which near-net product manufacturing is difficult, and the manufactured sintered body may be brittle.
  • the alloy base may include a tool steel system including at least one selected from the group consisting of Fe, STD 11, STD 61, SKH 2 and SKH 9; Or STS 430, STS 409, STS410, STS 440 (C), and STS 630 (17-4PH), but may include a stainless alloy system including at least one selected from the group consisting of, but is not limited thereto. .
  • the stainless alloy may be martensite type or precipitation hardening type.
  • the alloy base containing Fe is 3% by weight to 25% by weight of chromium (Cr), more than 0% by weight of nickel (Ni), 5% by weight or less, and 0.1% by weight of silicon (Si) in the alloy base containing Fe.
  • Cr chromium
  • Ni nickel
  • Si silicon
  • the cermet further includes at least one or more selected from the group consisting of chromium (Cr), nickel (Ni), silicon (Si), manganese (Mn), copper (Cu) and molybdenum (Mo), tensile strength, Hardness, toughness, stiffness, abrasion resistance, impact resistance, corrosion resistance and creep characteristics can be improved.
  • the reinforcing phase and the alloy base may be coherency.
  • Matching is related to the atomic array matching between newly formed particles (hardened phases, TiCs) and alloy bases.
  • good atomic arrangements have good mechanical properties, especially at high temperatures.
  • Precipitation hardening (including in situ reactivity) and mechanically alloying (MA) particles are coherent and thus have significantly better mechanical properties than the properties of the alloy matrix.
  • Ex-situ TiC mixing such as powder metallurgy (PM), exhibits an incoherent atomic arrangement of the reinforcement phase and matrix and is further degraded at the same content than that formed by in situ reactions. Will be shown.
  • the degree of consistency can be confirmed by directly observing the atomic arrangement by high magnification SEM, high magnification TEM, etc., or by changing the lattice parameter at the interface through XRD.
  • the cermet may be one having a relative density of 90% or more.
  • Relative density represents the degree of compactness (density). Since cermets are usually manufactured at a relative density (100%) close to true density, the closest to true density is tensile, compression, wear, fatigue, It is excellent in mechanical properties such as creep.
  • the alloy base comprising a carbon-based material, titanium-based material and at least one metal selected from the group consisting of Fe, Ni, Mo, Cr, Si Mn, Cu Mixing; Grinding the mixture; Compacting the ground mixture; And in-situ reaction sintering the molding.
  • FIG. 1 is a flow chart of a method for manufacturing a cermet according to an embodiment of the present invention.
  • the mixing step (S110), grinding step (S120), compression molding step (S130) and in situ reaction sintering step (S140) may include.
  • the carbon-based material the group consisting of graphite, graphene, carbon black, diamond, diamond like carbon (DLC), fullerene (fullerene, C60), carbon fiber, carbon nanorods and carbon nanotubes (CNT) It may include at least one selected from, but is not limited thereto.
  • the titanium-based material is at least one selected from the group consisting of iron titanium (FeTi), manganese titanium (MnTi), barium titanium (BaTi), strontium titanium (SrTi), nickel titanium (NiTi) and cobalt titanium (CoTi). It may be to include, but is not limited thereto.
  • the mixing ratio of the carbon-based material / the titanium-based material may be 0.25 to 3.0.
  • the mixing ratio of the carbonaceous material / titanium material is less than 0.25, residual Ti, which does not form carbide, remains in the base alloy in oxide form and acts as inclusions to significantly lower the low temperature and high temperature properties. And, if it is more than 3.0, there may be a problem such that the sintered stability is impaired by remaining in the base alloy of excess carbon not participating in the reaction, and the manufactured sintered body also has brittleness.
  • the carbonaceous material in the cermet may be 0.5% to 5.0% by weight. If the carbonaceous material is less than 0.5% by weight, it is difficult to obtain a dense and compact sintered body with the above-mentioned problems due to the Ti residue not participating in the reaction, and if it is more than 5.0% by weight, it is local due to the residual in the base alloy of excess carbon. As a result of the significant melting, the sintering stability is lowered, including a phenomenon in which near-net product manufacturing is difficult, and the manufactured sintered body may be brittle.
  • the alloy base may include a tool steel system including at least one selected from the group consisting of Fe, STD 11, STD 61, SKH 2 and SKH 9; Or STS 430, STS 409, STS410, STS 440 (C), and STS 630 (17-4PH), but may include a stainless alloy system including at least one selected from the group consisting of, but is not limited thereto. .
  • the stainless alloy may be martensite type or precipitation hardening type.
  • the alloy base containing Fe is 3% by weight to 25% by weight of chromium (Cr), more than 0% by weight of nickel (Ni), 5% by weight or less, and 0.1% by weight of silicon (Si) in the alloy base containing Fe.
  • Cr chromium
  • Ni nickel
  • Si silicon
  • the cermet further includes at least one or more selected from the group consisting of chromium (Cr), nickel (Ni), silicon (Si), manganese (Mn), copper (Cu) and molybdenum (Mo), tensile strength, Hardness, toughness, stiffness, abrasion resistance, impact resistance, corrosion resistance and creep characteristics can be improved.
  • Grinding the mixture (S120) may be ground in a grinding vessel.
  • the grinding may be dry grinding or wet grinding, the dry grinding may include a dry ball mill, a dry jet mill step, and the wet grinding may include an ultrasonic wave, a wet ball mill, a wet jet mill step.
  • ball milling can be performed.
  • the ball mill is a ball milling jar of a material selected from tool steel, stainless steel, cemented carbide, silicon nitride, alumina and zirconia, and the like. It can be carried out using a ball of material selected from these. For example, a ball having a diameter of 5 to 30 mm may be used, and all balls having the same size may be used, or balls having two or more sizes may be used together.
  • the ratio of the mixture and the ball introduced into the ball milling vessel may be in the range of 1: 1 to 1: 100 by weight. If the weight ratio of the mixture and the ball is less than 1: 1, the amount of impurities incorporated by the wear of the ball and the ball milling container may increase more than necessary, and if it exceeds 1: 100, the milling effect is lowered and uniform. Mixture preparation can be difficult.
  • ball milling is performed by filling a ball mill container with ethyl alcohol, heptane (organic solvent), etc., followed by a shaker mill, a vibratory mill, a planetary mill, or an attritor mill. ) May be included.
  • the container containing the ball performs revolution and rotation at the same time to maximize the collision energy of the ball to make the powder more fine and can be carried out by using a planetary mill to uniform particle size.
  • the reason for filling the ethyl alcohol in the ball milling vessel is to prevent the oxidation of the powder by oxygen in the air during milling.
  • the ball is separated using a whisk, and heated through an external separate heat source such as a heater to evaporate the ethyl alcohol, when the naked eye confirms that all of the ethyl alcohol is evaporated, the powder burns. Further fixing may be carried out to immediately remove the heat source and to dry with residual heat to prevent it.
  • the dried powder is spun in the form of a sponge and is crushed.
  • the powder is put in a grinder or mortar and pulverized, and the pulverized powder is put in a vacuum dryer, for example, after drying at a temperature of 65 ° C. or higher for 4 hours or more.
  • the pulverized powder can be obtained by filtering with a 63 ⁇ m eyepiece.
  • the powder (the resultant) synthesized by ball milling may be collected and molded into a predetermined shape to form a molded body.
  • zinc stearate may be applied as a lubricant to improve the lubricity on the mold wall of the compression molding machine.
  • the powder may be mixed with a binder in which 50 g of polyvinyl alcohol (PVA) or isopropyl alcohol (IPA) is dissolved in 1 l of distilled water, and the binder is 2.5 to 2.5 weight of the powder to be press-molded. 3 weight% can be mixed. The reason is that when the binder is less than 2.5% by weight, the molding is not good, and when the binder is more than 3% by weight, the binder flows out of the molded body.
  • PVA polyvinyl alcohol
  • IPA isopropyl alcohol
  • the powder in which the binder is well mixed is weighed and placed in the mold of the compression molding machine, and, for example, by pressing a pressure of 50 MPa, the powder compact can be press-molded. If the pressure is lower than 50 MPa, the density is lowered, so that the desired physical properties of the desired density cannot be obtained. If the pressure is higher than 50 MPa, the density is increased, but the overload is loaded, and cracks are likely to occur inside the molded body.
  • In-situ reaction sintering step (S140) may be performed in a vacuum or argon (Ar) atmosphere of 10 ⁇ 2 torr or less.
  • the in situ reaction sintering step may be to maintain for 0.5 hours to 24 hours in the temperature range of 1100 °C to 1400 °C and the pressure range of 1 ⁇ 10 -3 Torr to 1 ⁇ 10 1 Torr.
  • the sintering temperature is less than 1100 ° C.
  • the sintering pressure is less than 1 ⁇ 10 ⁇ 3 Torr
  • the sintering time is less than 0.5 hour, a sufficient sintering effect cannot be obtained
  • the sintering temperature is more than 1400 ° C., and the sintering pressure is 1
  • the result is underestimated because the particles of TiC occur abnormal grain growth to be the physical properties of hardness and flexural strength of the sintered body is lowered together.
  • the present invention may be characterized by undergoing a vacuum sintering process without pressure.
  • the pressure is increased by the pressurization, the control of the amount of carbon remaining in the sintered body due to the oxidation and the increase of the binder residue is virtually impossible, there may be a problem that is not industrially available.
  • the in situ reaction sintering step may further comprise a hot isostatic pressing (HIP) step.
  • HIP hot isostatic pressing
  • the sintered body is heated through a high temperature isostatic molding step, it plays a role of promoting densification. The characteristics are improved by removing defects such as residual pores, and a cermet of near-theoretical density can be manufactured.
  • the method may further include cooling to room temperature.
  • the carbon-based material and the titanium-based material may be to form a reinforcement phase including TiC. Therefore, the reinforcing phase (TiC) in the alloy matrix phase may be generated by the in-situ reaction.
  • the reinforcing phase may have a particle size of 30 ⁇ m to 150 ⁇ m.
  • the particle size of the reinforcing phase is less than 30 ⁇ m, a relatively large number of matrix alloys may cause a binder phase aggregation, and when the particle size exceeds 150 ⁇ m, the wettability of the matrix alloy against the reinforcing phase may be lowered, thereby lowering the toughness. have.
  • the reinforcement phase may be spherical.
  • the surface area can support higher applied stress, which has better mechanical properties, and delays the displacement of dislocations and the possibility of crack formation during material deformation at high temperatures. Will have an impact.
  • the reinforcing phase and the alloy base may be consistent. Such consistency can be directly observed by high magnification SEM, high magnification TEM, etc., or the change of lattice parameter at the interface through XRD to confirm the degree of consistency.
  • the cermet may be one having a relative density of 90% or more. Since cermets should be manufactured at relative density (100%), which is usually close to true density in terms of application characteristics, those close to true density are excellent in mechanical properties such as tensile, compression, wear, fatigue, and creep.
  • the cermet according to the present invention and a method for producing the same have excellent interfacial properties between the matrix alloy and the formed reinforcing phase, and thus excellent mechanical properties at room temperature and high temperature. It can proceed at much lower temperatures than the conventional sintering step, resulting in excellent plant life and cermet shape stability.
  • Ti powder and graphite powder have a C / Ti ratio of 1.5, as shown in Table 1 below, and 78.3 wt% of STD-11, 16.0 wt% of TiH 2 , and 5.8 wt% of carbon source as a base alloy.
  • the mixture was mixed to form a whole mixed powder.
  • the ball mill process was carried out on the ball mill apparatus for 20 hours at an optimum rotation speed of about 150 rpm considering the drop of the ball. Was carried out.
  • the pulverized powder is collected, charged into a hydraulic press and molded at a pressure of 50 MPa, and the molded body is sintered in a vacuum atmosphere of 5 ⁇ 10 -2 Torr for 2 hours in a vacuum furnace where the temperature is maintained at 1250 ° C., followed by a sintering furnace. It cooled to room temperature inside.
  • a sintered compact having a spherical TiC, a density of 6.85 g / cm 3 and a relative density of 98.2% was prepared.
  • Example 2 Same as Example 1 except that the C / Ti ratio was 1.0, the base alloy STD-11 content was 60.7 wt%, the TiH 2 was 31.7 wt%, the carbon source was 7.6 wt%, and the sintering temperature was set at 1280 ° C.
  • Spherical TiC, density 6.20 g / cm 3 which was prepared in the same manner as in Example 1 except that 48.9 wt% of Fe-34Ti was added without adding TiH 2 to 48.9 wt% of the known alloy STD-11. And a sintered compact having a relative density of 95.8% were prepared.
  • the sintered bodies of Examples 1 to 5 had a spherical TiC shape and excellent physical properties of density and relative density, compared to the sintered bodies of Comparative Example 1.
  • the relative densities of Examples 1 to 5 were close to true densities.

Abstract

The present invention relates to a cermet and a method for preparing the same. A cermet according to an embodiment of the present invention may comprise: a carbon-based material; a titanium-based material; and an alloy matrix containing at least one selected from the group consisting of Fe, Ni, Mo, Cr, Si, Mn, and Cu.

Description

써멧 및 그 제조 방법Cermet and its manufacturing method
본 발명은 써멧 및 그 제조 방법에 관한 것이다.The present invention relates to a cermet and a method for producing the same.
써멧(cermet)이란 세라믹(cermaic)과 금속(metal)의 합성어로서, 넓은 범위로 금속과 합금이 기지(Matrix)가 되며, 이에 세라믹 입자가 포함되어, 금속과 세라믹의 장점을 함께 지닌 재료를 말한다. 써멧 소재는 제조상 절삭 공구계에 가장 폭넓게 사용되는 초경합금(Cemented carbide)과 구별된다. 종래 기술 상의 써멧은 초경합금과 비교하여, 현저히 낮은 강도와 인성으로 적용상 한계가 있었으며, 이를 해결하기 위해서 기지 함량을 증가시키고, 이에 따른 경도의 감소를 기지상의 열처리 강화로 보상 가능한 개선형 써멧이 개발되었다. 개선형 써멧은 세라믹 입자 분말과 개별(individual elemenet) 또는 합금화(pre-alloyed) 분말 이 혼합 후 성형 소결(sintering) 단계를 거쳐 제조되며, 이와 같이 제조된 소재는 원료 분말의 특성과 소결 단계 등의 제조 조건에 따라 내모성과 인성이 크게 변화된다. 또한, 기지상의 충분한 젖음(wet)을 위해 기지상이 액상으로 변화되는 조건에서 소결이 이뤄지기 때문에 제조 가능한 제품의 크기에도 제약이 있다. 써멧을 제조하는 방식은 소결 단계를 이용한 분말야금 외에도 주조(casting) 단계와 목적하는 제품의 형상을 먼저 기공율(porosity)이 큰 프로폼(pre-form) 형태로 제작, 기지 합금을 액상으로 하여 프로폼에 가압 침투 시켜 제조하는 용융가압 함침(pressure infiltration)법 등이 있다. 여러 가지 제조법 중 분말야금법은, 높은 기지금속 가격 및 난삭재 가공으로 고비용을 요구하며, 제품 형상이 단순하며, 크기에 한계가 있고, 단계가 복잡하고, 액상단계 대비 높은 투자 설비비가 요구되는 단점이 있다. 다른 방법의 경우에도 저비용으로 저체적율의 금속복합재 중간제 제조가 가능하지만, 강화재 체적율/크기/형상 및 기지조직 제어에 난점이 있고, 복합재 내부에 다량의 결함(기공)이 생성되어 고온 구조특성(고온강도, 경도 등) 향상에 한계가 있으며, 기지합금 조성 제어 어려움으로 내식/내산화성 저하 문제가 있다. 특히 용융 가압함침법은 대형 및 near-net 형상의 복합재 제조가 가능하고, 복합소재 중심부와 표면부의 경사기능화 가능하여 특성 설계/재단이 가능하고, 금속용탕의 가압 함침 단계로 단계가 단순하며, 저비용을 요구하는데 있어 장점을 가지지만, 기지와 강화상 간 양호한 계면 형성이 어렵고, 고온 특성 저하의 문제점을 가져온다. 이렇게 각각의 단계는 장단점이 있어, 금속복합소재 제조 시 기지와 형성된 강화상 간의 계면특성이 우수하여 상온과 고온에서 기계적 특성(인장, 압축, 마모, 피로, creep 등)이 우수한 단계가 요구된다.Cermet is a compound word of ceramic and metal, and metal and alloy are matrix in a wide range, and it includes ceramic particles, which have the advantages of metal and ceramic. . The cermet material is distinguished from cemented carbide, which is the most widely used for cutting tool systems in manufacturing. Compared to cemented carbides in the prior art, there was a limitation in application due to the significantly lower strength and toughness.In order to solve this problem, an improved cermet was developed to increase the matrix content and compensate the decrease of hardness by strengthening the heat treatment on the matrix. It became. The improved cermet is manufactured by mixing the ceramic particle powder with individual elemenet or alloyed powder and then forming sintering step. The abrasion resistance and toughness vary greatly depending on the manufacturing conditions. In addition, there is a limitation in the size of the product that can be manufactured because sintering is performed under conditions in which the matrix phase is changed into a liquid phase for sufficient wet of the matrix phase. In addition to the powder metallurgy using the sintering step, the cermet is manufactured in the form of a casting form and a desired product in the form of a pre-form having a large porosity, and the base alloy is made into a liquid form. There is a pressure infiltration method prepared by pressurized penetration. Among various manufacturing methods, powder metallurgy demands high cost due to high base metal price and difficult machining, simple product shape, limited size, complicated stage, and high investment equipment cost compared to liquid phase. There is this. In other methods, it is possible to manufacture low volume fraction metal composite intermediates at low cost, but it is difficult to control the reinforcement volume ratio / size / shape and matrix structure, and a large amount of defects (pores) are generated inside the composite to make the high temperature structure. There is a limit in improving properties (high temperature strength, hardness, etc.), and there is a problem of lowering corrosion resistance / oxidation resistance due to difficulty in controlling the base alloy composition. In particular, the melt pressure impregnation method is capable of manufacturing large and near-net composites, and enables the design and cutting of characteristics by inclining the center and surface of the composite material, and the simple steps by the pressure impregnation step of the molten metal, and low cost. Although it has an advantage in demanding, it is difficult to form a good interface between the matrix and the reinforcing phase, and brings about a problem of deterioration in high temperature characteristics. Since each step has advantages and disadvantages, it is required to have excellent mechanical properties (tensile, compressive, abrasion, fatigue, creep, etc.) at room temperature and high temperature due to the excellent interfacial properties between the matrix and the formed reinforcement phase when manufacturing the metal composite material.
본 발명은 관련 종래 기술의 문제점을 해결하기 위한 것으로서, 본 발명의 목적은 기지 합금과 형성된 강화상 간의 계면특성이 우수하여 상온과 고온에서 기계적 특성이 우수한 써멧 및 그 제조 방법을 제공하는 것이다.The present invention is to solve the problems of the related art, it is an object of the present invention to provide a cermet excellent in the mechanical properties at room temperature and high temperature because of the excellent interfacial properties between the base alloy and the formed reinforcement phase and its manufacturing method.
또한, 본 발명의 다른 목적은 낮은 온도(soaking temperature)에서 금속복합소재를 제조시켜, 단계 설비 수명을 획기적으로 향상시키며, 크기가 큰 제품 제조 시 형상 변형이 적어, 재료 손실을 크게 낮출 수 있는 써멧 및 그 제조 방법을 제공하는 것이다.In addition, another object of the present invention is to produce a metal composite material at a low temperature (soaking temperature), significantly improving the life of the equipment installation step, less shape deformation during the manufacture of large products, the cermet that can significantly reduce material loss And a method for producing the same.
그러나, 본 발명이 해결하고자 하는 과제는 이상에서 언급한 과제로 제한되지 않으며, 언급되지 않은 또 다른 과제들은 아래의 기재로부터 당업자에게 명확하게 이해될 수 있을 것이다.However, the problem to be solved by the present invention is not limited to the above-mentioned problem, another task that is not mentioned will be clearly understood by those skilled in the art from the following description.
본 발명의 제1 측면은, 탄소계 물질; 티타늄계 물질; 및 Fe, Ni, Mo, Cr, Si, Mn 및 Cu로 이루어진 군으로부터 선택되는 적어도 어느 하나 이상을 포함하는 합금 기지;를 포함하는, 써멧을 제공할 수 있다.A first aspect of the invention, the carbon-based material; Titanium-based materials; And an alloy base including at least one selected from the group consisting of Fe, Ni, Mo, Cr, Si, Mn, and Cu.
상기 탄소계 물질 및 상기 티타늄계 물질은 티타늄카바이드(TiC)를 포함하는 강화상을 형성한 것일 수 있다.The carbon-based material and the titanium-based material may form a reinforcing phase including titanium carbide (TiC).
상기 강화상은, 상기 합금 기지 내에서 인시츄(in-situ) 반응으로 형성된 티타늄카바이드(TiC)를 포함하는 것일 수 있다.The reinforcing phase may include titanium carbide (TiC) formed by an in-situ reaction in the alloy matrix.
상기 강화상은 1.0 ㎛ 내지 50 ㎛의 입자 크기를 가지는 것일 수 있다.The reinforcing phase may have a particle size of 1.0 μm to 50 μm.
상기 강화상은 구형인 것일 수 있다.The reinforcement phase may be spherical.
상기 탄소계 물질은, 그래파이트, 그래핀, 카본블랙, 다이아몬드, 다이아몬드상카본(diamond like carbon; DLC), 플러렌(fullerene, C60), 탄소섬유, 탄소나노로드 및 탄소나노튜브(CNT)로 이루어진 군에서 선택되는 적어도 하나 이상을 포함하는 것일 수 있다.The carbon-based material, the group consisting of graphite, graphene, carbon black, diamond, diamond like carbon (DLC), fullerene (fullerene, C60), carbon fiber, carbon nanorods and carbon nanotubes (CNT) It may be to include at least one selected from.
상기 티타늄계 물질은, 철티타늄(FeTi), 망간티타늄(MnTi), 바륨티타늄(BaTi), 스트론튬티타늄(SrTi), 니켈티타늄(NiTi) 및 코발트티타늄(CoTi)으로 이루어진 군에서 선택되는 적어도 하나 이상을 포함하는 것일 수 있다.The titanium-based material is at least one selected from the group consisting of iron titanium (FeTi), manganese titanium (MnTi), barium titanium (BaTi), strontium titanium (SrTi), nickel titanium (NiTi) and cobalt titanium (CoTi). It may be to include.
상기 탄소계 물질/상기 티타늄계 물질의 혼합 비율은 0.25 내지 3.0인 것일 수 있다.The mixing ratio of the carbon-based material / the titanium-based material may be 0.25 to 3.0.
상기 써멧 중 상기 탄소계 물질은 0.5 중량% 내지 5.0 중량%인 것일 수 있다.The carbonaceous material in the cermet may be 0.5% to 5.0% by weight.
상기 합금 기지는, Fe를 포함하는, STD 11, STD 61, SKH 2 및 SKH 9로 이루어진 군에서 선택되는 적어도 하나 이상을 포함하는 공구강계; 또는 STS 430, STS 409, STS410, STS 440(C), 및 STS 630(17-4PH)로 이루어진 군에서 선택되는 적어도 하나 이상을 포함하는 스테인레스 합금계를 포함하는 것일 수 있다.The alloy base may include a tool steel system including at least one selected from the group consisting of Fe, STD 11, STD 61, SKH 2 and SKH 9; Or STS 430, STS 409, STS410, STS 440 (C), and STS 630 (17-4PH) may include a stainless alloy including at least one or more selected from the group consisting of.
상기 Fe를 포함하는 합금 기지는, 상기 Fe를 포함하는 합금 기지 중, 크롬(Cr) 3 중량% 내지 25 중량%, 니켈(Ni) 0 중량% 초과 5 중량% 이하, 실리콘(Si) 0.1 중량% 내지 3.0 중량%, 망간(Mn) 0 중량% 초과 1.0 중량% 이하, 구리(Cu) 0 중량% 초과 8.0 중량% 이하 및 몰리브덴(Mo) 0 중량% 초과 3.0 중량% 이하로 이루어진 군에서 선택되는 적어도 하나 이상을 포함하는 것일 수 있다.The alloy base containing Fe is 3% by weight to 25% by weight of chromium (Cr), more than 0% by weight of nickel (Ni), 5% by weight or less, and 0.1% by weight of silicon (Si) in the alloy base containing Fe. To 3.0% by weight, manganese (Mn) greater than 0% by weight 1.0% by weight, copper (Cu) greater than 0% by weight 8.0% by weight and molybdenum (Mo) greater than 0% by weight at least 3.0% by weight at least It may include one or more.
상기 강화상과 상기 합금 기지는 정합성인 것일 수 있다.The reinforcing phase and the alloy base may be consistent.
상기 써멧은 90% 이상의 상대밀도를 가지는 것일 수 있다.The cermet may be one having a relative density of 90% or more.
본 발명의 제2 측면은, 탄소계 물질, 티타늄계 물질 및 Fe, Ni, Mo, Cr, Si Mn, Cu로 이루어진 군으로부터 선택되는 적어도 하나 이상의 금속을 포함하는 합금 기지를 혼합하는 단계; 상기 혼합물을 분쇄하는 단계; 상기 분쇄된 혼합물을 압축하여 성형하는 단계; 및 상기 성형물을 인시츄 반응 소결하는 단계;를 포함하는, 써멧의 제조 방법을 제공할 수 있다.A second aspect of the present invention provides a method for mixing a carbonaceous material, a titanium-based material and an alloy base including at least one metal selected from the group consisting of Fe, Ni, Mo, Cr, Si Mn, and Cu; Grinding the mixture; Compacting the ground mixture; And in-situ reaction sintering the molded product, which may include a method of manufacturing a cermet.
상기 인시츄 반응 소결 단계는, 1100℃ 내지 1400℃의 온도 범위 및 1 × 10-3 Torr 내지 1 × 101 Torr의 압력 범위에서 0.5 시간 내지 24 시간 범위 동안 유지하는 것일 수 있다.The in situ reaction sintering step may be to maintain for 0.5 hours to 24 hours in the temperature range of 1100 ℃ to 1400 ℃ and pressure range of 1 × 10 -3 Torr to 1 × 10 1 Torr.
상기 탄소계 물질 및 상기 티타늄계 물질은 TiC를 포함하는 강화상을 형성하는 것일 수 있다.The carbon-based material and the titanium-based material may be to form a reinforcement phase including TiC.
상기 강화상은 1.0 ㎛ 내지 50 ㎛의 입자 크기를 가지는 것일 수 있다.The reinforcing phase may have a particle size of 1.0 μm to 50 μm.
상기 강화상은 구형인 것일 수 있다.The reinforcement phase may be spherical.
상기 강화상과 상기 합금 기지는 정합성인 것일 수 있다.The reinforcing phase and the alloy base may be consistent.
본 발명에 의한 써멧 및 그 제조 방법은, 합금 기지상 내에 세라믹 강화상(TiC)이 인시추(in-situ) 반응으로 생성된 써멧을 저가로 대량 생산할 수 있으며, 기지 합금과 형성된 강화상 간의 계면특성이 우수하여 상온과 고온에서 인장, 압축, 마모, 피로, 크리프(creep) 등의 기계적 특성이 우수한 써멧을 제조할 수 있다. 기존 소결 단계보다 훨씬 낮은 온도에서 진행 가능하며, 이로써 설비 수명과 써멧의 형상 안정성이 우수하고, 내마모성과 강도가 우수하다.The cermet according to the present invention and a method for manufacturing the same are capable of mass-producing a cermet produced by in-situ reaction of a ceramic-reinforced phase (TiC) in an alloy matrix phase at a low cost, and interfacial properties between the matrix alloy and the formed reinforced phase The excellent cermet can be manufactured at room temperature and high temperature with excellent mechanical properties such as tension, compression, wear, fatigue, creep, and the like. It can proceed at a much lower temperature than the conventional sintering step, thereby providing excellent equipment life and shape stability of the cermet, and excellent wear resistance and strength.
도 1은 본 발명의 일 실시예에 따른 써멧 제조 방법의 순서도이다.1 is a flow chart of a method for manufacturing a cermet according to an embodiment of the present invention.
이하 첨부된 도면을 참조하여 본 발명의 실시예들을 상세히 설명한다. 본 발명을 설명함에 있어서, 관련된 공지 기능 또는 구성에 대한 구체적인 설명이 본 발명의 요지를 불필요하게 흐릴 수 있다고 판단되는 경우에는 그 상세한 설명을 생략할 것이다. 또한, 본 명세서에서 사용되는 용어(terminology)들은 본 발명의 바람직한 실시예를 적절히 표현하기 위해 사용된 용어들로서, 이는 사용자, 운용자의 의도 또는 본 발명이 속하는 분야의 관례 등에 따라 달라질 수 있다. 따라서, 본 용어들에 대한 정의는 본 명세서 전반에 걸친 내용을 토대로 내려져야 할 것이다. 각 도면에 제시된 동일한 참조 부호는 동일한 부재를 나타낸다.Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, when it is determined that detailed descriptions of related known functions or configurations may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. Also, the terminology used herein is a term used to properly express a preferred embodiment of the present invention, which may vary depending on a user, an operator's intention, or customs in the field to which the present invention belongs. Therefore, the definitions of the terms should be made based on the contents throughout the specification. Like reference numerals in the drawings denote like elements.
명세서 전체에서, 어떤 부분이 어떤 구성요소를 "포함"한다고 할 때, 이는 특별히 반대되는 기재가 없는 한 다른 구성요소를 제외하는 것이 아니라 다른 구성 요소를 더 포함할 수 있는 것을 의미한다.Throughout the specification, when a part is said to "include" a certain component, it means that it can further include other components, without excluding other components unless specifically stated otherwise.
이하, 본 발명의 써멧 및 그 제조 방법에 대하여 실시예 및 도면을 참조하여 구체적으로 설명하도록 한다. 그러나, 본 발명이 이러한 실시예 및 도면에 제한되는 것은 아니다.Hereinafter, the cermet of the present invention and a manufacturing method thereof will be described in detail with reference to Examples and drawings. However, the present invention is not limited to these embodiments and drawings.
본 발명의 제1 측면에 따른 써멧은, 탄소계 물질; 티타늄계 물질; 및 Fe, Ni, Mo, Cr, Si, Mn 및 Cu로 이루어진 군으로부터 선택되는 적어도 어느 하나 이상을 포함하는 합금 기지;를 포함할 수 있다.The cermet according to the first aspect of the invention, the carbon-based material; Titanium-based materials; And an alloy base including at least one selected from the group consisting of Fe, Ni, Mo, Cr, Si, Mn, and Cu.
본 발명의 일 실시예에 따른 써멧은 상기 탄소계 물질 및 상기 티타늄계 물질은 티타늄카바이드(TiC)를 포함하는 강화상을 형성한 것일 수 있다. 따라서, 상기 합금 기지와 형성된 강화상 간의 계면특성이 우수하고, 상온과 고온에서 인장, 압축, 마모, 피로, 크리프(creep) 등의 기계적 특성이 우수하며, 액상 또는 반 액상기지 조건에서 진행되는 기존 소결 방식과 비교하여, 낮은 고상 영역에서도 높은 밀도를 가진다.The cermet according to an embodiment of the present invention may be a carbon-based material and the titanium-based material may form a reinforcing phase including titanium carbide (TiC). Therefore, the interfacial properties between the alloy base and the formed reinforcement phase are excellent, and mechanical properties such as tensile, compression, wear, fatigue, creep, etc. at room temperature and high temperature are excellent, and existing in liquid or semi-liquid base conditions. Compared with the sintering method, it has a high density even in a low solid state region.
상기 강화상은, 상기 합금 기지 내에서 인시츄(in-situ) 반응으로 형성된 티타늄카바이드(TiC)를 포함하는 것일 수 있다. 본 발명의 일 실시예에 따른 써멧은 분말야금 단계의 장점과 인시츄 주조 단계의 장점이 결합된 방식으로 제조할 수 있어, 단계 설비 수명을 획기적으로 향상시키며, 크기가 큰 제품 제조 시 기존 소결 단계보다 형상 변형이 적어, 재료 손실을 크게 낮출 수 있다.The reinforcing phase may include titanium carbide (TiC) formed by an in-situ reaction in the alloy matrix. The cermet according to an embodiment of the present invention can be manufactured in a manner that combines the advantages of the powder metallurgy step and the in-situ casting step, thereby significantly improving the life of the step equipment, the existing sintering step when manufacturing a large product There is less shape deformation, and material loss can be greatly reduced.
상기 강화상은 1.0 ㎛ 내지 50 ㎛의 입자 크기를 가지는 것일 수 있다. 상기 강화상의 입자 크기가 1.0 ㎛ 미만이면, 상대적으로 기지 합금이 많아 결합상 응집(binderpool)이 발생할 수 있고, 50 ㎛를 초과하면 강화상에 대한 기지 합금의 젖음성(wettability)이 떨어져 인성이 낮아지고, 입자간 거리가 커져 입자 석출 및 분산 강화 효과(Orowan 강화)가 저하될 수 있다. The reinforcing phase may have a particle size of 1.0 μm to 50 μm. If the particle size of the reinforcing phase is less than 1.0 μm, a relatively large number of matrix alloys may cause a binder phase aggregation, and if the particle size exceeds 50 μm, the wettability of the matrix alloy against the reinforcing phase may be lowered, leading to a lower toughness. As the interparticle distance increases, particle precipitation and dispersion strengthening effects (Orowan strengthening) may decrease.
상기 강화상은 구형인 것일 수 있다. 구형의 강화상의 경우, 표면적이 작어 더 높은 부가응력(applied stress)을 지탱가능하여 더 우수한 기계적 특성을 가지고, 크랙 전파 및 고온에서 소재 변형 시 전위(dislocation)의 이동의 지연과 크랙 형성 가능성 저하에 영향을 발휘하게 된다.The reinforcement phase may be spherical. In the case of spherical reinforced phases, the surface area is small and can support higher applied stress, which has better mechanical properties, resulting in delayed dislocation movement during crack propagation and material deformation at high temperatures and reduced crack formation potential. Will have an impact.
상기 탄소계 물질은, 그래파이트, 그래핀, 카본블랙, 다이아몬드, 다이아몬드상카본(diamond like carbon; DLC), 플러렌(fullerene, C60), 탄소섬유, 탄소나노로드 및 탄소나노튜브(CNT)로 이루어진 군에서 선택되는 적어도 하나 이상을 포함하는 것일 수 있으나, 이에 제한되지 않는다.The carbon-based material, the group consisting of graphite, graphene, carbon black, diamond, diamond like carbon (DLC), fullerene (fullerene, C60), carbon fiber, carbon nanorods and carbon nanotubes (CNT) It may include at least one selected from, but is not limited thereto.
상기 티타늄계 물질은, 철티타늄(FeTi), 망간티타늄(MnTi), 바륨티타늄(BaTi), 스트론튬티타늄(SrTi), 니켈티타늄(NiTi) 및 코발트티타늄(CoTi)으로 이루어진 군에서 선택되는 적어도 하나 이상을 포함하는 것일 수 있으나, 이에 제한되지 않는다.The titanium-based material is at least one selected from the group consisting of iron titanium (FeTi), manganese titanium (MnTi), barium titanium (BaTi), strontium titanium (SrTi), nickel titanium (NiTi) and cobalt titanium (CoTi). It may be to include, but is not limited thereto.
상기 탄소계 물질/상기 티타늄계 물질의 혼합 비율은 0.25 내지 3.0인 것일 수 있다. 상기 탄소계 물질/상기 티타늄계 물질의 혼합 비율이 0.25 미만인 경우, 탄화물을 형성하지 못한 잔류 Ti은 산화물 형태로 기지합금에 남아 개재물(inclusions)로 작용하여 저온 및 고온 물성을 현저하게 저하시키는 문제점이 있고, 3.0 초과인 경우 반응에 참여하지 못하는 과다 탄소의 기지합금 내 잔류로 소결 안정성을 해치며, 제조된 소결체 또한 취성을 지니게 하는 등의 문제점이 있을 수 있다.The mixing ratio of the carbon-based material / the titanium-based material may be 0.25 to 3.0. When the mixing ratio of the carbonaceous material / titanium material is less than 0.25, residual Ti, which does not form carbide, remains in the base alloy in oxide form and acts as inclusions to significantly lower the low temperature and high temperature properties. And, if it is more than 3.0, there may be a problem such that the sintered stability is impaired by remaining in the base alloy of excess carbon not participating in the reaction, and the manufactured sintered body also has brittleness.
상기 써멧 중 상기 탄소계 물질은 0.5 중량% 내지 5.0 중량%인 것일 수 있다. 상기 탄소계 물질이 0.5 중량% 미만인 경우, 반응에 참여하지 못한 Ti 잔류로 위에 상기된 문제점과 더불어 밀도가 높은 치밀한 소결체를 얻기가 어렵고, 5.0 중량% 초과인 경우 과다 탄소의 기지합금 내 잔류로 국부적으로 현저한 용융의 발생으로 near-net 제품 제조가 어려운 현상 등을 포함하여 소결 안정성이 저하되며, 제조된 소결체가 취성을 지니게 하는 등의 문제점이 있을 수 있다.The carbonaceous material in the cermet may be 0.5% to 5.0% by weight. If the carbonaceous material is less than 0.5% by weight, it is difficult to obtain a dense and compact sintered body with the above-mentioned problems due to the Ti residue not participating in the reaction, and if it is more than 5.0% by weight, it is local due to the residual in the base alloy of excess carbon. As a result of the significant melting, the sintering stability is lowered, including a phenomenon in which near-net product manufacturing is difficult, and the manufactured sintered body may be brittle.
상기 합금 기지는, Fe를 포함하는, STD 11, STD 61, SKH 2 및 SKH 9로 이루어진 군에서 선택되는 적어도 하나 이상을 포함하는 공구강계; 또는 STS 430, STS 409, STS410, STS 440(C), 및 STS 630(17-4PH)로 이루어진 군에서 선택되는 적어도 하나 이상을 포함하는 스테인레스 합금계를 포함하는 것일 수 있으나, 이에 제한되는 것은 아니다. 상기 스테인레스 합금계는 마르텐사이트형 또는 석출경화형일 수 있다.The alloy base may include a tool steel system including at least one selected from the group consisting of Fe, STD 11, STD 61, SKH 2 and SKH 9; Or STS 430, STS 409, STS410, STS 440 (C), and STS 630 (17-4PH), but may include a stainless alloy system including at least one selected from the group consisting of, but is not limited thereto. . The stainless alloy may be martensite type or precipitation hardening type.
상기 Fe를 포함하는 합금 기지는, 상기 Fe를 포함하는 합금 기지 중, 크롬(Cr) 3 중량% 내지 25 중량%, 니켈(Ni) 0 중량% 초과 5 중량% 이하, 실리콘(Si) 0.1 중량% 내지 3.0 중량%, 망간(Mn) 0 중량% 초과 1.0 중량% 이하, 구리(Cu) 0 중량% 초과 8.0 중량% 이하 및 몰리브덴(Mo) 0 중량% 초과 3.0 중량% 이하로 이루어진 군에서 선택되는 적어도 하나 이상을 포함하는 것일 수 있다. 이렇게 써멧에 크롬(Cr), 니켈(Ni), 실리콘(Si), 망간(Mn), 구리(Cu) 및 몰리브덴(Mo)로 이루어진 군에서 선택되는 적어도 하나 이상을 추가적으로 더 포함하면, 인장강도, 경도, 인성, 강직성, 내마모, 내충격성, 내식성 및 크립(creep) 특성 등을 향상시킬 수 있다.The alloy base containing Fe is 3% by weight to 25% by weight of chromium (Cr), more than 0% by weight of nickel (Ni), 5% by weight or less, and 0.1% by weight of silicon (Si) in the alloy base containing Fe. To 3.0% by weight, manganese (Mn) greater than 0% by weight 1.0% by weight, copper (Cu) greater than 0% by weight 8.0% by weight and molybdenum (Mo) greater than 0% by weight at least 3.0% by weight at least It may include one or more. If the cermet further includes at least one or more selected from the group consisting of chromium (Cr), nickel (Ni), silicon (Si), manganese (Mn), copper (Cu) and molybdenum (Mo), tensile strength, Hardness, toughness, stiffness, abrasion resistance, impact resistance, corrosion resistance and creep characteristics can be improved.
상기 강화상과 상기 합금 기지는 정합성(coherency)인 것일 수 있다. 정합성은 새로 형성된 입자 (강화상, TiC)와 합금 기지간 원자 배열상의 일치(atomic array matching)와 관련된 것으로, 일반적으로 원자적 배열이 우수하면 특히 고온에서 기계적 특성이 우수하다. 석출경화 (인시츄 반응도 포함) 및 기계 합금 (mechanically alloying; MA)으로 형성된 입자(oxide dispersion strengthened alloy ODS)는 정합성을 지니게 되며, 이에 따라 합금 기지가 지닌 특성보다 현저하게 기계적 특성이 우수해진다. 분말야금(powder metallurgy: PM)과 같은 익스 시츄(Ex-situ) 방식의 TiC 혼합은 강화상과 기지가 부정합(incoherent) 원자 배열을 나타내며, 인시츄 반응으로 형성된 것보다 동일 함량에서 더 저하된 특성을 보이게 된다. 정합성은 원자적 배열차로 고배율 SEM, 고배율 TEM 등으로 직접 원자배열을 관찰하거나, XRD를 통하여 계면에서의 격자상수(Lattice parameter) 변화를 보고 정합성의 정도를 확인할 수 있다.The reinforcing phase and the alloy base may be coherency. Matching is related to the atomic array matching between newly formed particles (hardened phases, TiCs) and alloy bases. In general, good atomic arrangements have good mechanical properties, especially at high temperatures. Precipitation hardening (including in situ reactivity) and mechanically alloying (MA) particles (oxide dispersion strengthened alloy ODS) are coherent and thus have significantly better mechanical properties than the properties of the alloy matrix. Ex-situ TiC mixing, such as powder metallurgy (PM), exhibits an incoherent atomic arrangement of the reinforcement phase and matrix and is further degraded at the same content than that formed by in situ reactions. Will be shown. The degree of consistency can be confirmed by directly observing the atomic arrangement by high magnification SEM, high magnification TEM, etc., or by changing the lattice parameter at the interface through XRD.
상기 써멧은 90% 이상의 상대밀도를 가지는 것일 수 있다. 상대밀도는 조밀한 정도 (밀도)를 나타내는 것으로, 써멧은 적용 특성상 통상 진밀도(true density)에 가까운 상대밀도 (100%)로 제조되어야 하기 때문에 진밀도에 가까운 것이 인장, 압축, 마모, 피로, 크리프(creep) 등의 기계적 특성이 우수하다.The cermet may be one having a relative density of 90% or more. Relative density represents the degree of compactness (density). Since cermets are usually manufactured at a relative density (100%) close to true density, the closest to true density is tensile, compression, wear, fatigue, It is excellent in mechanical properties such as creep.
본 발명의 제2 측면에 따른 써멧의 제조 방법은, 탄소계 물질, 티타늄계 물질 및 Fe, Ni, Mo, Cr, Si Mn, Cu로 이루어진 군으로부터 선택되는 적어도 하나 이상의 금속을 포함하는 합금 기지를 혼합하는 단계; 상기 혼합물을 분쇄하는 단계; 상기 분쇄된 혼합물을 압축하여 성형하는 단계; 및 상기 성형물을 인시츄 반응 소결하는 단계;를 포함할 수 있다.Method for producing a cermet according to the second aspect of the present invention, the alloy base comprising a carbon-based material, titanium-based material and at least one metal selected from the group consisting of Fe, Ni, Mo, Cr, Si Mn, Cu Mixing; Grinding the mixture; Compacting the ground mixture; And in-situ reaction sintering the molding.
도 1은 본 발명의 일 실시예에 따른 써멧 제조 방법의 순서도이다.1 is a flow chart of a method for manufacturing a cermet according to an embodiment of the present invention.
도 1을 참조하면, 본 발명의 본 발명의 일 실시예에 따른 써멧 제조 방법은, 혼합 단계(S110), 분쇄 단계(S120), 압축 성형 단계(S130) 및 인시츄 반응 소결 단계(S140)를 포함할 수 있다.1, the cermet manufacturing method according to an embodiment of the present invention, the mixing step (S110), grinding step (S120), compression molding step (S130) and in situ reaction sintering step (S140) It may include.
먼저, 혼합 단계(S110)는, 탄소계 물질, 티타늄계 물질 및 Fe, Ni, Mo, Cr, Si Mn, Cu로 이루어진 군으로부터 선택되는 적어도 하나 이상의 금속을 포함하는 합금 기지를 혼합 용기에 투입한 후 교반하여 혼합할 수 있다.First, the mixing step (S110), the alloy base containing at least one metal selected from the group consisting of carbon-based material, titanium-based material and Fe, Ni, Mo, Cr, Si Mn, Cu into the mixing vessel After stirring can be mixed.
상기 탄소계 물질은, 그래파이트, 그래핀, 카본블랙, 다이아몬드, 다이아몬드상카본(diamond like carbon; DLC), 플러렌(fullerene, C60), 탄소섬유, 탄소나노로드 및 탄소나노튜브(CNT)로 이루어진 군에서 선택되는 적어도 하나 이상을 포함하는 것일 수 있으나, 이에 제한되지 않는다.The carbon-based material, the group consisting of graphite, graphene, carbon black, diamond, diamond like carbon (DLC), fullerene (fullerene, C60), carbon fiber, carbon nanorods and carbon nanotubes (CNT) It may include at least one selected from, but is not limited thereto.
상기 티타늄계 물질은, 철티타늄(FeTi), 망간티타늄(MnTi), 바륨티타늄(BaTi), 스트론튬티타늄(SrTi), 니켈티타늄(NiTi) 및 코발트티타늄(CoTi)으로 이루어진 군에서 선택되는 적어도 하나 이상을 포함하는 것일 수 있으나, 이에 제한되지 않는다.The titanium-based material is at least one selected from the group consisting of iron titanium (FeTi), manganese titanium (MnTi), barium titanium (BaTi), strontium titanium (SrTi), nickel titanium (NiTi) and cobalt titanium (CoTi). It may be to include, but is not limited thereto.
상기 탄소계 물질/상기 티타늄계 물질의 혼합 비율은 0.25 내지 3.0인 것일 수 있다. 상기 탄소계 물질/상기 티타늄계 물질의 혼합 비율이 0.25 미만인 경우, 탄화물을 형성하지 못한 잔류 Ti은 산화물 형태로 기지합금에 남아 개재물(inclusions)로 작용하여 저온 및 고온 물성을 현저하게 저하시키는 문제점이 있고, 3.0 초과인 경우 반응에 참여하지 못하는 과다 탄소의 기지합금 내 잔류로 소결 안정성을 해치며, 제조된 소결체 또한 취성을 지니게 하는 등의 문제점이 있을 수 있다.The mixing ratio of the carbon-based material / the titanium-based material may be 0.25 to 3.0. When the mixing ratio of the carbonaceous material / titanium material is less than 0.25, residual Ti, which does not form carbide, remains in the base alloy in oxide form and acts as inclusions to significantly lower the low temperature and high temperature properties. And, if it is more than 3.0, there may be a problem such that the sintered stability is impaired by remaining in the base alloy of excess carbon not participating in the reaction, and the manufactured sintered body also has brittleness.
상기 써멧 중 상기 탄소계 물질은 0.5 중량% 내지 5.0 중량%인 것일 수 있다. 상기 탄소계 물질이 0.5 중량% 미만인 경우, 반응에 참여하지 못한 Ti 잔류로 위에 상기된 문제점과 더불어 밀도가 높은 치밀한 소결체를 얻기가 어렵고, 5.0 중량% 초과인 경우 과다 탄소의 기지합금 내 잔류로 국부적으로 현저한 용융의 발생으로 near-net 제품 제조가 어려운 현상 등을 포함하여 소결 안정성이 저하되며, 제조된 소결체가 취성을 지니게 하는 등의 문제점이 있을 수 있다.The carbonaceous material in the cermet may be 0.5% to 5.0% by weight. If the carbonaceous material is less than 0.5% by weight, it is difficult to obtain a dense and compact sintered body with the above-mentioned problems due to the Ti residue not participating in the reaction, and if it is more than 5.0% by weight, it is local due to the residual in the base alloy of excess carbon. As a result of the significant melting, the sintering stability is lowered, including a phenomenon in which near-net product manufacturing is difficult, and the manufactured sintered body may be brittle.
상기 합금 기지는, Fe를 포함하는, STD 11, STD 61, SKH 2 및 SKH 9로 이루어진 군에서 선택되는 적어도 하나 이상을 포함하는 공구강계; 또는 STS 430, STS 409, STS410, STS 440(C), 및 STS 630(17-4PH)로 이루어진 군에서 선택되는 적어도 하나 이상을 포함하는 스테인레스 합금계를 포함하는 것일 수 있으나, 이에 제한되는 것은 아니다. 상기 스테인레스 합금계는 마르텐사이트형 또는 석출경화형일 수 있다.The alloy base may include a tool steel system including at least one selected from the group consisting of Fe, STD 11, STD 61, SKH 2 and SKH 9; Or STS 430, STS 409, STS410, STS 440 (C), and STS 630 (17-4PH), but may include a stainless alloy system including at least one selected from the group consisting of, but is not limited thereto. . The stainless alloy may be martensite type or precipitation hardening type.
상기 Fe를 포함하는 합금 기지는, 상기 Fe를 포함하는 합금 기지 중, 크롬(Cr) 3 중량% 내지 25 중량%, 니켈(Ni) 0 중량% 초과 5 중량% 이하, 실리콘(Si) 0.1 중량% 내지 3.0 중량%, 망간(Mn) 0 중량% 초과 1.0 중량% 이하, 구리(Cu) 0 중량% 초과 8.0 중량% 이하 및 몰리브덴(Mo) 0 중량% 초과 3.0 중량% 이하로 이루어진 군에서 선택되는 적어도 하나 이상을 포함하는 것일 수 있다. 이렇게 써멧에 크롬(Cr), 니켈(Ni), 실리콘(Si), 망간(Mn), 구리(Cu) 및 몰리브덴(Mo)로 이루어진 군에서 선택되는 적어도 하나 이상을 추가적으로 더 포함하면, 인장강도, 경도, 인성, 강직성, 내마모, 내충격성, 내식성 및 크립(creep) 특성 등을 향상시킬 수 있다.The alloy base containing Fe is 3% by weight to 25% by weight of chromium (Cr), more than 0% by weight of nickel (Ni), 5% by weight or less, and 0.1% by weight of silicon (Si) in the alloy base containing Fe. To 3.0% by weight, manganese (Mn) greater than 0% by weight 1.0% by weight, copper (Cu) greater than 0% by weight 8.0% by weight and molybdenum (Mo) greater than 0% by weight at least 3.0% by weight at least It may include one or more. If the cermet further includes at least one or more selected from the group consisting of chromium (Cr), nickel (Ni), silicon (Si), manganese (Mn), copper (Cu) and molybdenum (Mo), tensile strength, Hardness, toughness, stiffness, abrasion resistance, impact resistance, corrosion resistance and creep characteristics can be improved.
상기 혼합물을 분쇄하는 단계(S120)는 분쇄 용기에서 분쇄할 수 있다.Grinding the mixture (S120) may be ground in a grinding vessel.
상기 분쇄는 건식 분쇄 또는 습식 분쇄하는 것일 수 있으며, 상기 건식 분쇄는 건식 볼밀, 건식 제트밀 단계를 포함하고, 상기 습식 분쇄는 초음파, 습식 볼밀, 습식 제트밀 단계를 포함할 수 있다. 대표적으로 볼 밀링을 수행할 수 있다. 상기 볼 밀링은 공구강(tool steel), 스테인레스강(stainless steel), 초경합금(cemented carbide), 질화규소(silicon nitride), 알루미나(alumina) 및 지르코니아(zirconia) 등에서 선택되는 재질의 볼 밀링 용기(jar)와 이들 중에서 선택되는 재질의 볼을 사용하여 수행할 수 있다. 볼은, 예를 들어, 5 내지 30 mm의 직경인 것을 사용할 수 있는데, 모두 같은 크기를 갖는 것을 사용하거나 2가지 이상의 크기를 가지는 볼을 함께 사용할 수도 있다. 또한, 볼 밀링 용기에 투입되는 혼합물과 볼의 비율은 중량비로 1 : 1 내지 1 : 100 범위가 되도록 할 수 있다. 혼합물과 볼의 중량비가 1:1 미만일 경우, 볼과 볼 밀링 용기의 마모에 의해 혼입되는 불순물의 양이 필요 이상으로 증가할 수 있고, 1 : 100을 초과하는 경우, 밀링 효과가 저하되어 균일한 혼합체 제조가 어려울 수 있다. 구체적으로, 볼 밀링은 볼 밀링 용기에 에틸알콜 및 헵탄(유기용매) 등을 충진한 후 쉐이커 밀(shaker mill), 진동 밀(vibratory mill), 유성 밀(planetary mill) 또는 어트리터 밀(attritor mill)을 포함할 수 있다. 상기 볼 밀링의 종류 중에서 볼이 들어 있는 용기가 공전과 자전을 동시에 수행함으로써 볼의 충돌에너지를 극대화시켜 분말을 더욱 미세하게 만들 수 있으며 입자크기를 고르게 해주는 유성 밀을 이용하여 수행할 수 있다. 여기서, 볼 밀링 용기에 에틸알콜을 충진하는 이유는 밀링 중 공기중의 산소에 의한 분말의 산화를 막기 위함이다.The grinding may be dry grinding or wet grinding, the dry grinding may include a dry ball mill, a dry jet mill step, and the wet grinding may include an ultrasonic wave, a wet ball mill, a wet jet mill step. Typically ball milling can be performed. The ball mill is a ball milling jar of a material selected from tool steel, stainless steel, cemented carbide, silicon nitride, alumina and zirconia, and the like. It can be carried out using a ball of material selected from these. For example, a ball having a diameter of 5 to 30 mm may be used, and all balls having the same size may be used, or balls having two or more sizes may be used together. In addition, the ratio of the mixture and the ball introduced into the ball milling vessel may be in the range of 1: 1 to 1: 100 by weight. If the weight ratio of the mixture and the ball is less than 1: 1, the amount of impurities incorporated by the wear of the ball and the ball milling container may increase more than necessary, and if it exceeds 1: 100, the milling effect is lowered and uniform. Mixture preparation can be difficult. Specifically, ball milling is performed by filling a ball mill container with ethyl alcohol, heptane (organic solvent), etc., followed by a shaker mill, a vibratory mill, a planetary mill, or an attritor mill. ) May be included. Among the types of ball milling, the container containing the ball performs revolution and rotation at the same time to maximize the collision energy of the ball to make the powder more fine and can be carried out by using a planetary mill to uniform particle size. Here, the reason for filling the ethyl alcohol in the ball milling vessel is to prevent the oxidation of the powder by oxygen in the air during milling.
분쇄 단계(S120) 이 후에, 채를 사용하여 볼을 분리시키고, 에틸알콜을 증발시키기 위해 히터와 같은 외부의 별도 열원을 통해 가열을 하여, 육안으로 에틸알콜이 모두 증발된 것이 확인되면 분말이 타는 것을 방지하도록 열원을 즉시 제거 후 잔열로 건조하는 고정을 추가로 수행할 수 있다. 이처럼 건조된 분말은, 스펀지 형태를 띄게 되며 뭉쳐지게 되는데, 이를 분쇄기나 막자사발 등에 넣어 분쇄시키고, 분쇄된 분말은 진공건조기에 넣어, 예를 들어, 65℃이상의 온도에서 4 시간 이상 건조시킨 후, 63 ㎛의 채눈을 가진 채로 걸러내어 분쇄 분말을 확보할 수 있다.After the grinding step (S120), the ball is separated using a whisk, and heated through an external separate heat source such as a heater to evaporate the ethyl alcohol, when the naked eye confirms that all of the ethyl alcohol is evaporated, the powder burns. Further fixing may be carried out to immediately remove the heat source and to dry with residual heat to prevent it. The dried powder is spun in the form of a sponge and is crushed. The powder is put in a grinder or mortar and pulverized, and the pulverized powder is put in a vacuum dryer, for example, after drying at a temperature of 65 ° C. or higher for 4 hours or more. The pulverized powder can be obtained by filtering with a 63 μm eyepiece.
압축 성형 단계(S130)는, 볼 밀링으로 합성한 분말 (결과물)을 회수하여 정해진 형상으로 성형하여 성형체를 형성하는 것일 수 있다.In the compression molding step S130, the powder (the resultant) synthesized by ball milling may be collected and molded into a predetermined shape to form a molded body.
압축 성형기의 금형 벽면에 윤활성을 향상시키기 위하여 윤활제로서, 예를 들어, 스테아린산 아연(zinc stearate)을 도포할 수 있다. 그리고, 상기 분말은, 예를 들어, 증류수 1 l에 폴리비닐알콜(PVA) 또는 이소프로필알콜(IPA) 50 g을 용해한 결합제와 혼합할 수 있는데, 상기 결합제는 압착 성형하고자 하는 분말 중량의 2.5 내지 3중량%를 혼합할 수 있다. 그 이유는, 결합제가 2.5 중량%미만인 경우, 성형이 잘 되지 않고, 반대로 3 중량% 초과인 경우 결합제가 성형체 외부로 흘러나오게 되기 때문이다. 이처럼, 결합제를 잘 혼합한 분말은 정량을 취하여 압착 성형기의 금형 내부에 넣은 후, 예를 들어, 50 MPa의 압력을 가함으로써, 분말 성형체를 압착 성형할 수 있다. 50 MPa보다 압력이 낮을 경우에는 밀도가 낮아지기 때문에 원하고자 하는 밀도의 물성을 얻을 수 없으며, 50 MPa 보다 압력이 높을 경우에는 밀도는 높아지나 과하중이 부하되어 도리어 성형체 내부에 균열 등이 일어나기 쉽다.For example, zinc stearate may be applied as a lubricant to improve the lubricity on the mold wall of the compression molding machine. The powder may be mixed with a binder in which 50 g of polyvinyl alcohol (PVA) or isopropyl alcohol (IPA) is dissolved in 1 l of distilled water, and the binder is 2.5 to 2.5 weight of the powder to be press-molded. 3 weight% can be mixed. The reason is that when the binder is less than 2.5% by weight, the molding is not good, and when the binder is more than 3% by weight, the binder flows out of the molded body. In this way, the powder in which the binder is well mixed is weighed and placed in the mold of the compression molding machine, and, for example, by pressing a pressure of 50 MPa, the powder compact can be press-molded. If the pressure is lower than 50 MPa, the density is lowered, so that the desired physical properties of the desired density cannot be obtained. If the pressure is higher than 50 MPa, the density is increased, but the overload is loaded, and cracks are likely to occur inside the molded body.
인시츄 반응 소결 단계(S140)는, 10-2 torr 이하의 진공 또는 아르곤(Ar) 분위기에서 수행할 수 있다.In-situ reaction sintering step (S140) may be performed in a vacuum or argon (Ar) atmosphere of 10 −2 torr or less.
상기 인시츄 반응 소결 단계는, 1100℃ 내지 1400℃의 온도 범위 및 1 × 10-3 Torr 내지 1 × 101 Torr 의 압력 범위에서 0.5 시간 내지 24 시간 범위 동안 유지하는 것일 수 있다. 인시츄 소결 시, 소결 온도가 1100℃ 미만, 소결 압력이 1 × 10-3 Torr 미만, 소결 시간이 0.5 시간 미만이면, 충분한 소결 효과를 얻을 수 없고, 소결 온도가 1400℃ 초과, 소결 압력이 1 × 101 Torr 이상, 소결 시간이 24 시간을 초과하면, 과소결되어 TiC 의 입자가 비정상적 입자성장이 일어나기 때문에 소결체의 경도 및 꺽임강도의 물성도 함께 저하되게 된다.The in situ reaction sintering step may be to maintain for 0.5 hours to 24 hours in the temperature range of 1100 ℃ to 1400 ℃ and the pressure range of 1 × 10 -3 Torr to 1 × 10 1 Torr. In in-situ sintering, if the sintering temperature is less than 1100 ° C., the sintering pressure is less than 1 × 10 −3 Torr, and the sintering time is less than 0.5 hour, a sufficient sintering effect cannot be obtained, and the sintering temperature is more than 1400 ° C., and the sintering pressure is 1 If more than 1 × 10 Torr for 24 hours or more, the sintering time, the result is underestimated because the particles of TiC occur abnormal grain growth to be the physical properties of hardness and flexural strength of the sintered body is lowered together.
특히 본 발명은 가압 없이 진공소결 과정을 거치는 것이 특징일 수 있다. 가압에 의해서 압력이 증가되면, 산화 및 바인더 잔류의 증가로 소결체 내 잔류하는 탄소량의 제어가 사실상 불가능 하게 되어, 산업적으로 이용 불가능한 문제점이 있을 수 있다.In particular, the present invention may be characterized by undergoing a vacuum sintering process without pressure. When the pressure is increased by the pressurization, the control of the amount of carbon remaining in the sintered body due to the oxidation and the increase of the binder residue is virtually impossible, there may be a problem that is not industrially available.
인시츄 반응 소결 단계(S140) 이후에, 고온등방압성형(hot isostatic pressing; HIP) 단계를 더 포함할 수 있다. 고온등방압성형 단계를 통하여 소결체를 승온 시킴에 따라 치밀화를 촉진시키는 역할을 하게 되는데 잔류된 기공 등의 결함 제거로 특성이 향상되고, 이론 밀도에 가까운 써멧의 제조가 가능하다.After the in situ reaction sintering step (S140), it may further comprise a hot isostatic pressing (HIP) step. As the sintered body is heated through a high temperature isostatic molding step, it plays a role of promoting densification. The characteristics are improved by removing defects such as residual pores, and a cermet of near-theoretical density can be manufactured.
또한, 인시츄 반응 소결 단계(S140) 이후에, 상온까지 냉각시키는 단계를 더 포함할 수 있다.In addition, after the in-situ reaction sintering step (S140), the method may further include cooling to room temperature.
상기 탄소계 물질 및 상기 티타늄계 물질은 TiC를 포함하는 강화상을 형성하는 것일 수 있다. 따라서, 합금 기지상 내에 강화상(TiC)이 인시추(in-situ) 반응으로 생성된 것일 수 있다.The carbon-based material and the titanium-based material may be to form a reinforcement phase including TiC. Therefore, the reinforcing phase (TiC) in the alloy matrix phase may be generated by the in-situ reaction.
상기 강화상은 30 ㎛ 내지 150 ㎛의 입자 크기를 가지는 것일 수 있다. 상기 강화상의 입자 크기가 30 ㎛ 미만이면, 상대적으로 기지 합금이 많아 결합상 응집(binderpool)이 발생할 수 있고, 150 ㎛를 초과하면 강화상에 대한 기지 합금의 젖음성(wettability)이 떨어져 인성이 낮아질 수 있다.The reinforcing phase may have a particle size of 30 μm to 150 μm. When the particle size of the reinforcing phase is less than 30 μm, a relatively large number of matrix alloys may cause a binder phase aggregation, and when the particle size exceeds 150 μm, the wettability of the matrix alloy against the reinforcing phase may be lowered, thereby lowering the toughness. have.
상기 강화상은 구형인 것일 수 있다. 구형의 강화상의 경우, 표면적이 적어 더 높은 부가응력(applied stress)을 지탱가능하여 더 우수한 기계적 특성을 가지고, 크랙 전파 및 고온에서 소재 변형 시 전위(dislocation)의 이동의 지연과 크랙 형성 가능성 저하에 영향을 발휘하게 된다.The reinforcement phase may be spherical. In the case of spherical reinforced phases, the surface area can support higher applied stress, which has better mechanical properties, and delays the displacement of dislocations and the possibility of crack formation during material deformation at high temperatures. Will have an impact.
상기 강화상과 상기 합금 기지는 정합성인 것일 수 있다. 이러한 정합성은 원자적 배열차로 고배율 SEM, 고배율 TEM 등으로 직접 원자배열을 관찰하거나, XRD를 통하여 계면에서의 격자상수(Lattice parameter) 변화를 보고 정합성의 정도를 확인할 수 있다.The reinforcing phase and the alloy base may be consistent. Such consistency can be directly observed by high magnification SEM, high magnification TEM, etc., or the change of lattice parameter at the interface through XRD to confirm the degree of consistency.
상기 써멧은 90% 이상의 상대밀도를 가지는 것일 수 있다. 써멧은 적용 특성상 통상 진밀도(true density)에 가까운 상대밀도 (100%)로 제조되어야 하기 때문에 진밀도에 가까운 것이 인장, 압축, 마모, 피로, 크리프(creep) 등의 기계적 특성이 우수하다. The cermet may be one having a relative density of 90% or more. Since cermets should be manufactured at relative density (100%), which is usually close to true density in terms of application characteristics, those close to true density are excellent in mechanical properties such as tensile, compression, wear, fatigue, and creep.
본 발명에 의한 써멧 및 그 제조 방법은 기지 합금과 형성된 강화상 간의 계면특성이 우수하여 상온과 고온에서 기계적 특성이 우수하다. 기존 소결 단계보다 훨씬 낮은 온도에서 진행 가능하며, 이로써 설비 수명과 써멧 형상 안정성이 우수하다.The cermet according to the present invention and a method for producing the same have excellent interfacial properties between the matrix alloy and the formed reinforcing phase, and thus excellent mechanical properties at room temperature and high temperature. It can proceed at much lower temperatures than the conventional sintering step, resulting in excellent plant life and cermet shape stability.
이하, 실시예를 통하여 본 발명을 더욱 상세하게 설명하고자 하나, 하기의 실시예는 단지 설명의 목적을 위한 것이며, 본 발명의 범위를 한정하고자 하는 것은 아니다.Hereinafter, the present invention will be described in more detail with reference to Examples, but the following Examples are for illustrative purposes only and are not intended to limit the scope of the present invention.
[실시예 1]Example 1
TiC 복합재를 제조하기 위해, 하기 표 1에서와 같이 Ti 분말 및 그래파이트 분말을 C/Ti 비율이 1.5이고, 기지합금으로는 STD-11 78.3 중량%, TiH2 16.0 중량%, 탄소 소스 5.8 중량%를 혼합하여 전체 혼합분말을 조성하였다. 그리고, 스테인레스 재질로 형성된 볼밀 용기에 혼합분말과 용매인 헵탄(heptane)을 충진한 후, 준비된 볼밀 용기를 볼밀 장치 위에 올리고 볼의 낙하를 고려한 최적 회전속도인 약 150 rpm으로 20 시간 동안 볼밀 공정을 실시하였다. 분쇄한 분말을 회수하여 유압 프레스에 장입하여 50 MPa의 압력으로 성형하고, 성형체를 5× 10-2 Torr의 진공분위기, 1250℃에서 온도가 유지되는 진공로에서 2 시간 동안 소결을 실시한 후 소결로 내부에서 상온까지 냉각시켰다. 그 결과 구형 형상의 TiC, 밀도 6.85 g/cm3, 상대밀도 98.2%를 가지는 소결체를 제조하였다.In order to prepare the TiC composite, Ti powder and graphite powder have a C / Ti ratio of 1.5, as shown in Table 1 below, and 78.3 wt% of STD-11, 16.0 wt% of TiH 2 , and 5.8 wt% of carbon source as a base alloy. The mixture was mixed to form a whole mixed powder. After filling the mixed powder and heptane (heptane) into a ball mill container made of stainless steel, the ball mill process was carried out on the ball mill apparatus for 20 hours at an optimum rotation speed of about 150 rpm considering the drop of the ball. Was carried out. The pulverized powder is collected, charged into a hydraulic press and molded at a pressure of 50 MPa, and the molded body is sintered in a vacuum atmosphere of 5 × 10 -2 Torr for 2 hours in a vacuum furnace where the temperature is maintained at 1250 ° C., followed by a sintering furnace. It cooled to room temperature inside. As a result, a sintered compact having a spherical TiC, a density of 6.85 g / cm 3 and a relative density of 98.2% was prepared.
[실시예 2]Example 2
C/Ti 비율을 1.0으로 하고, TiH2 17.5 중량%, 탄소 소스 4.2 중량%로 하고, 소결 온도 1390℃로 한 것을 제외하고 실시예 1과 동일하게 실시하여 구형 형상의 TiC, 밀도 6.90 g/cm3, 상대밀도 99.0%를 가지는 소결체를 제조하였다.Spherical TiC with a C / Ti ratio of 1.0, 17.5 wt% of TiH 2 , 4.2 wt% of a carbon source, and a sintering temperature of 1390 ° C., and a spherical TiC density 6.90 g / cm 3 , a sintered compact having a relative density of 99.0% was prepared.
[실시예 3]Example 3
C/Ti 비율을 1.0으로 하고, 기지합금 STD-11 함량을 60.7 중량%로 하고, TiH2 31.7 중량%, 탄소 소스 7.6 중량%로 하고, 소결 온도 1280℃로 한 것을 제외하고 실시예 1과 동일하게 실시하여 구형 형상의 TiC, 밀도 6.25 g/cm3, 상대밀도 97.8%를 가지는 소결체를 제조하였다.Same as Example 1 except that the C / Ti ratio was 1.0, the base alloy STD-11 content was 60.7 wt%, the TiH 2 was 31.7 wt%, the carbon source was 7.6 wt%, and the sintering temperature was set at 1280 ° C. The sintered compact having spherical TiC, density 6.25 g / cm 3 and relative density 97.8% was prepared.
[실시예 4]Example 4
기지합금을 STS630으로 하여 함량 78.3 중량%로 하고, 소결 온도 1280℃로 한 것을 제외하고 실시예 1과 동일하게 실시하여 구형 형상의 TiC, 밀도 6.95 g/cm3, 상대밀도 99.7%를 가지는 소결체를 제조하였다.Sintered body having a spherical TiC, a density of 6.95 g / cm 3 , and a relative density of 99.7% by the same method as in Example 1 except that the base alloy was set to STS630 to 78.3% by weight, and the sintering temperature was set to 1280 ° C. Prepared.
[실시예 5]Example 5
기지합금 STD-11 함량 48.9 중량%로 하고, TiH2를 첨가하지 않고, Fe-34Ti 45.3 중량%를 추가한 것을 제외하고 실시예 1과 동일하게 실시하여 구형 형상의 TiC, 밀도 6.20 g/cm3, 상대밀도 95.8%를 가지는 소결체를 제조하였다.Spherical TiC, density 6.20 g / cm 3 , which was prepared in the same manner as in Example 1 except that 48.9 wt% of Fe-34Ti was added without adding TiH 2 to 48.9 wt% of the known alloy STD-11. And a sintered compact having a relative density of 95.8% were prepared.
[비교예 1]Comparative Example 1
C/Ti 비율을 0.15로 하고, TiH2 19.4%, 탄소 소스 2.3 중량%로 하고, 소결 온도 1420℃로 한 것을 제외하고 실시예 1과 동일하게 실시하여 구형 형상의 TiC, 밀도 5.58 g/cm3, 상대밀도 89.7%를 가지는 소결체를 제조하였다.Spherical TiC, density 5.58 g / cm 3 , carried out in the same manner as in Example 1 except that the C / Ti ratio was 0.15, TiH 2 was 19.4%, the carbon source was 2.3 wt%, and the sintering temperature was 1420 ° C. And a sintered compact having a relative density of 89.7% were prepared.
혼합체 설계 및 제조 결과는 하기 표 1에 모두 나타내었다.The mixture design and production results are all shown in Table 1 below.
Figure PCTKR2015002161-appb-I000001
Figure PCTKR2015002161-appb-I000001
상기에서 살펴본 바와 같이 실시예 1 내지 5의 소결체는 비교예 1의 소결체에 비해 TiC 형상이 구형이고, 밀도, 상대 밀도의 물성이 모두 우수함을 알 수 있었다. 특히 실시예 1 내지 5의 상대밀도는 진밀도에 가까운 것을 알 수 있었다.As described above, it was found that the sintered bodies of Examples 1 to 5 had a spherical TiC shape and excellent physical properties of density and relative density, compared to the sintered bodies of Comparative Example 1. In particular, it was found that the relative densities of Examples 1 to 5 were close to true densities.
가이드 롤러(huide roller)를 제조한 결과 공구소재용으로 사용되는 고강도 TiC를 제조할 수 있음을 확인하였다.As a result of the manufacture of the guide roller (huide roller) it was confirmed that the high-strength TiC used for the tool material can be produced.
이상과 같이 본 발명은 비록 한정된 실시예와 도면에 의해 설명되었으나, 본 발명은 상기의 실시예에 한정되는 것은 아니며, 본 발명이 속하는 분야에서 통상의 지식을 가진 자라면 이러한 기재로부터 다양한 수정 및 변형이 가능하다. 그러므로, 본 발명의 범위는 설명된 실시예에 국한되어 정해져서는 아니 되며, 후술하는 특허청구범위뿐 아니라 이 특허청구범위와 균등한 것들에 의해 정해져야 한다.As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

Claims (19)

  1. 탄소계 물질;Carbon-based materials;
    티타늄계 물질; 및Titanium-based materials; And
    Fe, Ni, Mo, Cr, Si, Mn 및 Cu로 이루어진 군으로부터 선택되는 적어도 어느 하나 이상을 포함하는 합금 기지;An alloy base comprising at least any one selected from the group consisting of Fe, Ni, Mo, Cr, Si, Mn and Cu;
    를 포함하는, 써멧.Including, cermet.
  2. 제1항에 있어서,The method of claim 1,
    상기 탄소계 물질 및 상기 티타늄계 물질은 티타늄카바이드(TiC)를 포함하는 강화상을 형성한 것인, 써멧.Wherein the carbon-based material and the titanium-based material is to form a reinforcing phase containing titanium carbide (TiC), cermet.
  3. 제2항에 있어서,The method of claim 2,
    상기 강화상은, 상기 합금 기지 내에서 인시츄(in-situ) 반응으로 형성된 티타늄카바이드(TiC)를 포함하는 것인, 써멧.The reinforcement phase is a cermet comprising titanium carbide (TiC) formed in-situ reaction in the alloy base.
  4. 제2항에 있어서,The method of claim 2,
    상기 강화상은 1.0 ㎛ 내지 50 ㎛의 입자 크기를 가지는 것인, 써멧.Wherein the reinforcing phase has a particle size of 1.0 μm to 50 μm.
  5. 제2항에 있어서,The method of claim 2,
    상기 강화상은 구형인 것인, 써멧.The reinforcement phase is a spherical one, it is spherical.
  6. 제1항에 있어서,The method of claim 1,
    상기 탄소계 물질은, 그래파이트, 그래핀, 카본블랙, 다이아몬드, 다이아몬드상카본(diamond like carbon; DLC), 플러렌(fullerene, C60), 탄소섬유, 탄소나노로드 및 탄소나노튜브(CNT)로 이루어진 군에서 선택되는 적어도 하나 이상을 포함하는 것인, 써멧.The carbon-based material, the group consisting of graphite, graphene, carbon black, diamond, diamond like carbon (DLC), fullerene (fullerene, C60), carbon fiber, carbon nanorods and carbon nanotubes (CNT) One or more selected from, the cermet.
  7. 제1항에 있어서,The method of claim 1,
    상기 티타늄계 물질은, 철티타늄(FeTi), 망간티타늄(MnTi), 바륨티타늄(BaTi), 스트론튬티타늄(SrTi), 니켈티타늄(NiTi) 및 코발트티타늄(CoTi)으로 이루어진 군에서 선택되는 적어도 하나 이상을 포함하는 것인, 써멧.The titanium-based material is at least one selected from the group consisting of iron titanium (FeTi), manganese titanium (MnTi), barium titanium (BaTi), strontium titanium (SrTi), nickel titanium (NiTi) and cobalt titanium (CoTi). To include, cermet.
  8. 제1항에 있어서,The method of claim 1,
    상기 탄소계 물질/상기 티타늄계 물질의 혼합 비율은 0.25 내지 3.0인 것인, 써멧.The mixing ratio of the carbon-based material / titanium-based material is 0.25 to 3.0, the cermet.
  9. 제1항에 있어서,The method of claim 1,
    상기 써멧 중 상기 탄소계 물질은 0.5 중량% 내지 5.0 중량%인 것인, 써멧.Wherein the carbonaceous material in the cermet is 0.5% to 5.0% by weight.
  10. 제1항에 있어서,The method of claim 1,
    상기 합금 기지는, Fe를 포함하는,The alloy base contains Fe,
    STD 11, STD 61, SKH 2 및 SKH 9로 이루어진 군에서 선택되는 적어도 하나 이상을 포함하는 공구강계; 또는 A tool steel system including at least one selected from the group consisting of STD 11, STD 61, SKH 2 and SKH 9; or
    STS 430, STS 409, STS410, STS 440(C), 및 STS 630(17-4PH)로 이루어진 군에서 선택되는 적어도 하나 이상을 포함하는 스테인레스 합금계Stainless alloy system including at least one selected from the group consisting of STS 430, STS 409, STS410, STS 440 (C), and STS 630 (17-4PH)
    를 포함하는 것인, 써멧.To include, cermet.
  11. 제10항에 있어서,The method of claim 10,
    상기 Fe를 포함하는 합금 기지는,The alloy base containing Fe,
    상기 Fe를 포함하는 합금 기지 중, 크롬(Cr) 3 중량% 내지 25 중량%, 니켈(Ni) 0 중량% 초과 5 중량% 이하, 실리콘(Si) 0.1 중량% 내지 3.0 중량%, 망간(Mn) 0 중량% 초과 1.0 중량% 이하, 구리(Cu) 0 중량% 초과 8.0 중량% 이하 및 몰리브덴(Mo) 0 중량% 초과 3.0 중량% 이하로 이루어진 군에서 선택되는 적어도 하나 이상을 포함하는 것인, 써멧.In the alloy base containing Fe, 3 wt% to 25 wt% of chromium (Cr), more than 0 wt% of nickel (Ni) and 5 wt% or less, 0.1 wt% to 3.0 wt% of silicon (Si), and manganese (Mn) More than 0% by weight 1.0% by weight, copper (Cu) more than 0% by weight 8.0% by weight and molybdenum (Mo) more than 0% by weight 3.0% by weight at least one selected from the group consisting of .
  12. 제1항에 있어서,The method of claim 1,
    상기 강화상과 상기 합금 기지는 정합성인 것인, 써멧.Wherein said reinforcing phase and said alloy base are consistent.
  13. 제1항에 있어서,The method of claim 1,
    상기 써멧은 90% 이상의 상대밀도를 가지는 것인, 써멧.Wherein the cermet has a relative density of at least 90%.
  14. 탄소계 물질, 티타늄계 물질 및 Fe, Ni, Mo, Cr, Si Mn, Cu로 이루어진 군으로부터 선택되는 적어도 하나 이상의 금속을 포함하는 합금 기지를 혼합하는 단계;Mixing an alloy base comprising a carbon-based material, a titanium-based material and at least one metal selected from the group consisting of Fe, Ni, Mo, Cr, Si Mn, Cu;
    상기 혼합물을 분쇄하는 단계;Grinding the mixture;
    상기 분쇄된 혼합물을 압축하여 성형하는 단계; 및Compacting the ground mixture; And
    상기 성형물을 인시츄 반응 소결하는 단계;In-situ reaction sintering the molding;
    를 포함하는, 써멧의 제조 방법.Including, the manufacturing method of the cermet.
  15. 제14항에 있어서,The method of claim 14,
    상기 인시츄 반응 소결 단계는, 1100℃ 내지 1400℃의 온도 범위 및 1 10-3 Torr 내지 1 × 101 Torr의 압력 범위에서 0.5 시간 내지 24 시간 범위 동안 유지하는 것인, 써멧의 제조 방법.The in-situ reaction sintering step is to maintain for 0.5 hours to 24 hours in the temperature range of 1100 ℃ to 1400 ℃ and a pressure range of 1 10 -3 Torr to 1 × 10 1 Torr, cermet manufacturing method.
  16. 제14항에 있어서,The method of claim 14,
    상기 탄소계 물질 및 상기 티타늄계 물질은 TiC를 포함하는 강화상을 형성하는 것인, 써멧의 제조 방법.Wherein the carbon-based material and the titanium-based material form a reinforcing phase comprising TiC.
  17. 제16항에 있어서,The method of claim 16,
    상기 강화상은 1.0 ㎛ 내지 50 ㎛의 입자 크기를 가지는 것인, 써멧의 제조 방법.Wherein the reinforcing phase has a particle size of 1.0 μm to 50 μm.
  18. 제16항에 있어서,The method of claim 16,
    상기 강화상은 구형인 것인, 써멧의 제조 방법.The reinforcing phase is spherical, the manufacturing method of the cermet.
  19. 제18항에 있어서,The method of claim 18,
    상기 강화상과 상기 합금 기지는 정합성인 것인, 써멧의 제조 방법.The reinforcing phase and the alloy base is consistent, the manufacturing method of the cermet.
PCT/KR2015/002161 2014-07-15 2015-03-06 Cermet and method for preparing same WO2016010226A1 (en)

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KR101935389B1 (en) * 2017-05-18 2019-04-03 주식회사 대화알로이테크 Cermet for wear-resistant with controlled volume ratio of carbide and method for manufacturing the same
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KR102478654B1 (en) * 2017-07-11 2022-12-16 한국재료연구원 Composite with interface materials and manufacturing method for the same
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KR102271297B1 (en) * 2018-12-12 2021-06-29 주식회사 포스코 Composite of titanium-carbon, method of preparing same and sintering materil comprising same
KR102120015B1 (en) * 2019-09-19 2020-06-09 재단법인 경북하이브리드부품연구원 Metal Matrix Composite Using Nano Diamond Powder and Metal Powder and Method for Manufacturing the Same
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