JP3872653B2 - Manufacturing method of composite material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention is a composite material.FeeMore specifically, a composite material having both high strength, high hardness, and high toughness with respect to the manufacturing methodFeeIt relates to a manufacturing method.
[0002]
[Prior art]
  Composite materials containing metals and ceramics are widely used in various fields. For example, tungsten carbide-cobalt cemented carbide obtained by sintering cobalt and tungsten carbide and titanium carbide cermet obtained by sintering molybdenum and titanium carbide are employed as cutting tools.
[0003]
  Properties of the composite such as toughness, strength, and hardness vary depending on the composition ratio of the metal and the ceramic. That is, the higher the metal composition ratio, the better the strength and toughness, while the lower the metal composition ratio, the better the hardness. Therefore, the composition ratio of the metal and the ceramic is selected so that the composite material has desired characteristics. For example, in the cutting tool as described above, the metal composition ratio tends to be lowered in order to ensure hardness and wear resistance and extend the life. In order to further improve the hardness and wear resistance of the surface of the blade, a coating made of TiN or TiC is applied to the surface by a physical vapor deposition (PVD) method or a chemical vapor deposition (CVD) method. May be formed.
[0004]
[Problems to be solved by the invention]
  By the way, when a film is formed by the PVD method or the CVD method, there is an inconvenience that the size and shape of the work are restricted. That is, since a film cannot be formed efficiently, the manufacturing cost of a blade or the like is increased. Furthermore, the coating easily peels off under high stress.
[0005]
  In order to eliminate the need for forming a coating, it seems as if it is effective to further reduce the composition ratio of the metal in the composite material to further improve the hardness of the composite material. However, in this case, the hardness and wear resistance of the composite material are ensured while the toughness is lowered. In a cutting tool with reduced toughness, a problem that cracks and chips easily occur during use is caused.
[0006]
  When the metal composition ratio is increased in order to eliminate such a problem, as described above, the situation where the hardness and strength of the composite material are lowered is caused.
[0007]
  Thus, hardness, strength and toughness are in a trade-off relationship, and it is difficult to improve both hardness, strength and toughness.
[0008]
  The present invention has been made to solve the above-described problems, and is a composite material having high hardness and high strength but also improved toughness.FeeAn object is to provide a manufacturing method.
[0009]
[Means for Solving the Problems]
  In order to achieve the above object, the present invention provides WC, TiC, TiN, TaC, NbC, VC, Cr₂C_Three70 to 97% by weight of at least one non-oxide ceramic selected from the group consisting of Fe, Ni, Co, and at least one metal selected from the group consisting of two or more of these, 30% by weight, and B is dissolved in the metal in a weight ratio of 7 to 30 ppm.The particle size of the non-oxide ceramic particles is 5 to 100 μm, and the particles are fused together to form a three-dimensional network structure and the non-oxide ceramic particles are nitrided. A method for producing a composite material with curved ends,
  A molding step of molding a mixed powder of non-oxide ceramic particles and metal particles into a molded body;
  An application step of applying a boron compound-containing solution to all or part of the surface of the molded body;
  Sintering the molded body coated with the boron compound-containing solution into a sintered body, and solid-dissolving boron from the boron compound contained in the boron compound-containing solution in the metal; and
  Have
  The boron compound contained in the boron compound-containing solution is titanium boride, molybdenum boride, hexagonal boron nitride or boron carbide,
  The atmosphere for obtaining the sintered body is nitrogen.It is characterized by that.
[0010]
  The metal in which B is solid-dissolved in the above proportion has improved hardness and strength as compared with that before solid solution. Therefore, even when the metal composition ratio is increased in order to improve the toughness of the composite material, the hardness and strength can be ensured. That is, a composite material having both high hardness, high strength, and high toughness can be configured.
[0011]
  Here, when B is less than 7 ppm, the effect of improving the strength, hardness and toughness of the composite material is poor. On the other hand, if it exceeds 30 ppm, the toughness of the composite material is lowered and becomes brittle.
[0012]
  In the composite material, the particle size of the non-oxide ceramic particles may reach 5 to 100 μm, and the particles may be fused together to form a three-dimensional network structure. This is because B also functions as a grain growth accelerator for promoting grain growth of the non-oxide ceramic particles. In this case, since the non-oxide ceramic is excellent in strength, toughness and hardness, the composite material is also excellent in strength, toughness and hardness.
[0013]
  Here, the three-dimensional network structure is defined as a three-dimensionally linked solid particle chain formed by sterically bonding linear particle chains formed by fusing a plurality of particles to each other. .
[0014]
  Further, the non-oxide ceramic particles are nitrided and the end is curved.For,Since the stress concentration occurring at the particle end point is reduced, excellent durability is exhibited in the composite material..In other words, the life of the composite material can be extended..
[0015]
  As aboveB constituting the fine compound dissolved or dispersed in the boron compound-containing solution applied in the application step functions as a particle growth agent for non-oxide ceramic particles in the sintering step. For this reason, since the particles grow large, the strength, toughness and hardness of the non-oxide ceramics are improved.
[0016]
  Moreover, since B is dissolved in the metal, the hardness and strength of the metal are also improved. For this reason, hardness and strength can be ensured even when the metal composition ratio is increased in order to improve the toughness of the composite material.
[0017]
  Thus, the composite material which has high hardness, high intensity | strength, and high toughness can be manufactured by apply | coating a boron compound containing solution to a molded object.
[0018]
  MaIn addition, the present inventionWC, TiC, TiN, TaC, NbC, VC, Cr ₂ C _Three 70 to 97% by weight of at least one non-oxide ceramic selected from the group consisting of Fe, Ni, Co, and at least one metal selected from the group consisting of two or more of these, 30% by weight, B is solid-dissolved in the metal by 7 to 30 ppm by weight, the particle size of the non-oxide ceramic particles is 5 to 100 μm, and the particles are fused together A method of manufacturing a composite material in which a three-dimensional network structure is formed and the particles of the non-oxide ceramics are nitrided and curved at the ends,
  A molding step of molding a mixed powder of non-oxide ceramic particles and metal particles into a molded body;
  A primary sintering step of sintering the molded body to form a porous body;
  Inside the porous bodyGrain growth promoterAn impregnation step of impregnating the containing solution;
  An application step of applying a boron compound-containing solution to all or part of the surface of the porous body;
  The porous body coated with the boron compound-containing solution is sintered to obtain a sintered body.At the same time, boron from the boron compound contained in the boron compound-containing solution is dissolved in the metal.A secondary sintering process;
  HaveAnd
  The boron compound contained in the boron compound-containing solution is titanium boride, molybdenum boride, hexagonal boron nitride or boron carbide,
  The atmosphere when obtaining the sintered body is nitrogen.It is characterized by doing.
[0019]
  Thus, even if it replaces with a molded object and is a porous body, the composite material which has high hardness, high intensity | strength, and high toughness by the above-mentioned effect | action of B can be manufactured.
[0020]
  In this case,Grain growth promoterContained in the containing solutionGrain growth promoterThis further promotes the grain growth of the non-oxide ceramic particles, so that it is possible to obtain a composite material that is more excellent in hardness, strength, and toughness than the composite material obtained by the manufacturing method described above.
[0021]
  WhereGrain growth promoterContained in contained solutionGrain growth promoterAs a suitable example, at least one of Fe, Ni, Co, Mn, Cr, Ti, Zr, and Al can be cited.
[0022]
  In any case, the atmosphere when obtaining the sintered body is nitrogen..B also functions as a nitriding catalyst for the above non-oxide ceramics. Therefore, at this time, the end portion of the non-oxide ceramic particles is bent by being nitrided with nitrogen. For this reason, the stress concentration occurring at the particle end point is reduced, and as a result, excellent durability is exhibited in the composite material, so that the life of the composite material can be extended.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, the composite material according to the present inventionFeePreferred embodiments of the manufacturing method will be described and described in detail with reference to the accompanying drawings.
[0024]
  The composite material according to the present embodiment contains a non-oxide ceramic and a metal, and a boron compound is dissolved in the metal.
[0025]
  Non-oxide ceramics are components that provide a composite material with high hardness and high strength. That is, the higher the composition ratio of the non-oxide ceramic, the higher the hardness and strength of the composite material.
[0026]
  Non-oxide ceramics include WC, TiC, TiN, TaC, NbC, VC, Cr₂C_ThreeAt least one selected from the group is selected. In these, grain growth is promoted by a boron compound described later at the time of sintering when obtaining a composite material. That is, in the composite material according to the present embodiment, non-oxide ceramic particles are fused together to form a three-dimensional network structure of non-oxide ceramic particles. For this reason, since the non-oxide ceramic is excellent in strength, toughness and hardness, the composite material is also excellent in strength, toughness and hardness.
[0027]
  Note that when the sintering for obtaining the composite material is performed in a nitrogen atmosphere, the end portions of the non-oxide ceramic particles are curved and rounded. In this case, since the stress concentration occurring at the particle end point is reduced, the composite material exhibits excellent durability and has a long life.
[0028]
  The particle size of the non-oxide ceramics in the composite material is generally in the range of 5 to 100 μm and substantially uniform. Since most of the particles used as the raw material have a particle size of 0.1 to 3 μm, sintering causes a particle growth of about 20 to 50 times.
[0029]
  Metal is a component that provides high toughness to the composite material. That is, the higher the metal content, the higher the toughness of the composite material. Therefore, when the composite material is used as a cutting tool, the cutting tool is not easily cracked or chipped.
[0030]
  As the metal, a metal that does not melt when the non-oxide ceramic particles are sintered, in other words, a metal having a melting point higher than the temperature at which the non-oxide ceramic particles are densified is selected. The Specifically, it is at least one selected from the group of Fe, Ni, Co, and an alloy composed of two or more of these. In addition to these, Cr, V, Mo, and Al may be further added. In this case, the strength of the composite material is further improved.
[0031]
  In the composite material according to the present embodiment, boron (B) is solid-dissolved in the metal in a weight ratio of 7 to 30 ppm. In such a metal in which a very small amount of B is dissolved, the strength and hardness are improved as compared with those before the solid solution. For this reason, even when the composition ratio of the metal in the composite material is large, the strength and hardness can be improved as compared with the composite material containing a metal in which B is not dissolved. Further, since the metal composition ratio is large, the toughness is also improved. For example, a WC—Co based composite material containing 15% by weight of Co in which B is solid-dissolved is non-oxidized as compared to a WC—Co based composite material containing 6% by weight of Co in which B is not dissolved. Although the composition ratio of ceramics is small, it is excellent in strength and hardness. Further, since the Co composition ratio is remarkably high, the toughness is remarkably excellent.
[0032]
  Furthermore, this composite material is excellent in oxidation resistance and heat resistance and has a low surface frictional resistance coefficient as compared with a composite material containing a metal in which B is not dissolved in solid. For this reason, the composite material according to the present embodiment can be used, for example, as a suitable mold material or blade material.
[0033]
  In addition, when B is less than 7 ppm, the effect of improving the strength, hardness and toughness of the composite material is poor. On the other hand, if it exceeds 30 ppm, the toughness of the composite material is lowered and becomes brittle. The solid solution amount of B can be quantified by, for example, wet chemical analysis.
[0034]
  As will be described later, this B diffuses into the metal using the boron compound contained in the boron compound-containing solution applied to the surface of the molded body or porous body as the composite material. Here, the boron compound-containing solution refers to a solution in which a boron compound is dissolved or dispersed.
[0035]
  In a composite material, when the composition ratio of non-oxide ceramics increases, the composition ratio of metals inevitably decreases. As a result, the toughness of the composite material decreases. For this reason, the composition ratio of the non-oxide ceramic and the metal is set in a range in which the hardness, strength and toughness of the composite material are not impaired. Specifically, the composition ratio of the non-oxide ceramic is 70 to 97% by weight, and the metal composition ratio is 3 to 30% by weight.
[0036]
  The actual composition ratio may be set according to the hardness and toughness required for the application. For example, when a composite material is used as a constituent material for blades, a preferred composition ratio (weight ratio, hereinafter the same) between the non-oxide ceramic and the metal is 85 to 97:15 to 3.
[0037]
  This composite material can be manufactured as follows.
[0038]
  FIG. 1 shows a flowchart of a method for manufacturing a composite material according to the first embodiment of the present invention (hereinafter referred to as a first manufacturing method). The first manufacturing method includes a molding step S1 for obtaining a molded body, an application step S2 for applying a boron compound-containing solution to all or part of the surface of the molded body, and the molded body coated with the boron compound-containing solution. And a sintering step S3 which is sintered to form a sintered body (composite material).
[0039]
  First, in the forming step S1, a mixed powder of non-oxide ceramic particles and metal particles is prepared.
[0040]
  Here, as non-oxide ceramics, WC, TiC, TiN, TaC, NbC, VC, Cr₂C_ThreeOn the other hand, at least one selected from the group consisting of Fe, Ni, Co, and an alloy composed of two or more of these is selected as the metal. As described above, Cr, V, Mo, and Al may be further added to the metal. Of course, the non-oxide ceramic particles and the metal particles are mixed in a ratio of 85:15 to 97: 3.
[0041]
  A compacting load is applied to the mixed powder thus prepared to produce a compact. As the molding method, a press molding method or a sheet molding method can be employed.
[0042]
  Next, a boron compound-containing solution is applied to the surface of the obtained molded body in the application step S2. Application can be accomplished, for example, by spray application.
[0043]
  In the composite material finally obtained, the hardness is improved only on the surface on which the boron compound-containing solution is applied and on the inside thereof. Therefore, the boron compound-containing solution may be applied only to the region where the hardness is to be improved. For example, when a boron compound-containing solution is applied to the entire surface of the molded body, the composite material has a high hardness throughout. On the other hand, when the boron compound-containing solution is applied only to one end surface of the molded body, the hardness of the one end surface and the inside thereof is significantly increased as compared to the other end surface and the inside thereof.
[0044]
  As a suitable example of the boron compound-containing solution, titanium boride (TiB₂), Molybdenum boride (MoB)₂), Hexagonal boron nitride (h-BN) or boron carbide (B_FourExamples thereof include a solution in which C) is dissolved or dispersed in an organic solvent such as xylene, toluene or acetone. Since these organic solvents are volatile, they can be easily removed from the molded body.
[0045]
  The solid solution amount of B in the metal can be controlled by setting the coating amount of the boron compound-containing solution.
[0046]
  Finally, in the sintering step S3, the molded body is sintered. That is, non-oxide ceramic particles are grown.
[0047]
  At this time, the boron compound first promotes the non-oxide ceramic particles. For this reason, non-oxide ceramic particles are easily fused to each other. As a result, the particles grow to about 5 to 100 μm and a three-dimensional network structure is formed by the particles being fused together. . For this reason, a composite material excellent in strength, toughness and hardness can be obtained.
[0048]
  The sintering step S3 is preferably performed in a nitrogen atmosphere. The boron compound also functions as a nitriding catalyst that promotes the reaction between the non-oxide ceramic and nitrogen. Since the end portion of the nitrided non-oxide ceramic particle is curved and rounded, the stress concentration at the particle end point is reduced. For this reason, it becomes possible to obtain a composite material having excellent durability.
[0049]
  And B which comprises a boron compound dissolves in a metal, and improves both the intensity | strength and hardness of a metal. As a result, a sintered body (composite material) excellent in strength and hardness can be produced even when the composition ratio of the metal is larger than that of the composite material containing a metal not containing B as a solid solution. It reaches. By increasing the composition ratio of the metal, the toughness of the composite material is also improved.
[0050]
  Next, a method for manufacturing a composite material according to a second embodiment of the present invention (hereinafter referred to as a second manufacturing method) will be described with reference to FIG. In addition, about the process which performs operation similar to a 1st manufacturing method, the process name same as a 1st manufacturing method is attached | subjected, and the detailed description is abbreviate | omitted.
[0051]
  The second production method includes a molding step S10 for obtaining a molded body, a primary sintering step S20 that sinters the molded body into a porous body, and the porous body.Grain growth promoterImpregnation step S30 for impregnating the containing solution, coating step S40 for applying the boron compound-containing solution to all or part of the surface of the porous body, and re-sintering the porous body coated with the boron compound-containing solution And a secondary sintering step S50 to obtain a sintered body (composite material).
[0052]
  First, in the molding step S10, a molded body is produced in accordance with the molding step S1. The molding load at this time is set to such an extent that the open pores of the molded body are not blocked in order to ensure that the porous body is obtained in the primary sintering step S20. Specifically, the molding load is preferably about 100 to 300 MPa. In this case, since the metal particles can be prevented from causing plastic deformation, the open pores of the molded body are not blocked.
[0053]
  Next, in the primary sintering step S20, the molded body is sintered to form a porous body so that open pores remain. If a dense sintered body is formed at this point, in the impregnation step S30,Grain growth promoterThis is because it becomes difficult to impregnate the containing solution.
[0054]
  Therefore, the sintering temperature and time in the primary sintering step S20 are set so that the metal particles are fused with each other and the neck is formed between the particles. That is, in the primary sintering step S20, the non-oxide ceramic particles are not densified.
[0055]
  Next, in the impregnation step S30, inside the porous bodyGrain growth promoterImpregnating the containing solution. In particular,Grain growth promoterThe porous body is immersed in the containing solution. By this immersion, through the open pores of the porous bodyGrain growth promoterThe contained solution penetrates into the interior.
[0056]
  Grain growth promoterIs not particularly limited as long as it is a substance that promotes grain growth of non-oxide ceramic particles in the secondary sintering step S50, but Fe, Ni, Co, Mn, Cr, Ti, Zr, Al, etc. Can be cited as a suitable example.Grain growth promoterAs the containing solution, a solution obtained by dissolving or dispersing a metal salt such as nitrate or acetate containing the metal in a solvent may be used. The solvent is not particularly limited, and water, alcohol, and the like can be given as suitable examples. Alternatively, these metal alkoxides such as titanium isopropoxideGrain growth promoterYou may make it use as a containing solution. Of course, the metal alkoxide may be diluted with an organic solvent.
[0057]
  After performing the impregnation step S30, by natural standingGrain growth promoterThe containing solution is dried to remove the solvent. Alternatively, the porous sintered body is heated at 330 to 390 K for about 30 minutes.Grain growth promoterThe contained solution may be dried. As a result, most of the solvent is volatilized and removed from the porous body.Grain growth promoterRemains.
[0058]
  Next, in a coating step S40, a boron compound-containing solution is applied to the surface of the porous body. As described above, the coating can be performed by spray coating or the like.
[0059]
  Next, in the secondary sintering step S50, the porous body coated with the boron compound-containing solution is re-sintered to obtain a sintered body (composite material). That is, similarly to the sintering step S3, non-oxide ceramic particles are grown and B is dissolved in the metal.
[0060]
  The grain growth of the non-oxide ceramic particles in the secondary sintering step S50 is as described above in addition to B.Grain growth promoterAlso promoted by. For this reason, the hardness and strength of the obtained composite material are larger than those of the composite material manufactured by the first manufacturing method. Of course, even in this case, a three-dimensional network structure is formed by the fusion of particles by the action of B.
[0061]
  This secondary sintering step S50 is also preferably performed in a nitrogen atmosphere, similarly to the sintering step S3 in the first manufacturing method. As described above, the ends of the nitrided non-oxide ceramic particles are rounded, so that the stress concentration at the ends of the particles is reduced, and as a result, excellent durability is exhibited in the composite material.
[0062]
  Of course, B constituting the boron compound is dissolved in the metal to improve both the strength and hardness of the metal. That is, a sintered body (composite material) having high strength and hardness is produced even when the composition ratio of the metal is larger than that of the composite material containing the metal not containing B as a solid solution. Increasing the composition ratio of the metal inevitably improves toughness.
[0063]
  Thus, by applying the boron-containing solution to the surface of the molded body or porous body, a three-dimensional network structure in which the non-oxide ceramic particles are fused together is formed. , Hardness and toughness are improved. For this reason, the composite material which has the outstanding intensity | strength, hardness, and toughness is obtained.
[0064]
  In addition, since B constituting the boron compound is dissolved in the metal, the strength and hardness of the metal are improved. Therefore, since the composition ratio of the metal in the composite material can be increased, the strength, hardness and toughness of the composite material can be further improved.
[0065]
【Example】
  90 wt% of tungsten carbide (WC) particles having an average particle diameter of 1 μm and 10 wt% of cobalt (Co) particles having an average particle diameter of 1.4 μm were wet-mixed using hexane to obtain a mixed powder. Next, this mixed powder was formed into a cylindrical shape with a pressure of 120 MPa. With respect to the entire surface of the cylindrical molded body thus obtained, h-BN or B_FourA solution in which C was dispersed in xylene was spray-coated.
[0066]
  Next, these cylindrical shaped bodies were sintered by holding them at 1700 K for 1 hour under a nitrogen atmosphere to obtain cylindrical sintered bodies having a diameter of 30 mm and a length of 30 mm. These are referred to as Examples 1 and 2, respectively. In addition, when the structure of each sintered compact of Examples 1 and 2 was observed with an electron microscope, the WC particles were fused together to form a three-dimensional network structure, and the ends of the WC particles were It was observed to be rounded.
[0067]
  Separately from these, 90% by weight of WC particles having an average particle diameter of 1 μm and 10% by weight of Co particles having an average particle diameter of 1.4 μm were wet mixed using hexane to obtain a mixed powder. Next, this mixed powder was formed into a cylindrical shape with a pressure of 120 MPa. The cylindrical molded body thus obtained was made a porous body by holding it at 1200 K for 30 minutes while evacuating the inside of the heating furnace.
[0068]
  Subsequently, these porous bodies were immersed in an aqueous nickel nitrate solution having a concentration of 10%, whereby Ni ions were dispersed inside the porous body. Furthermore, the porous body was dried by holding at 350K for 1 hour. For the entire surface of the porous body thus obtained, h-BN or B_FourA solution in which C was dispersed in xylene was spray-coated.
[0069]
  Next, each porous body was sintered by holding it at 1700 K for 1 hour under a nitrogen atmosphere to obtain a cylindrical sintered body having a diameter of 30 mm and a length of 30 mm. These are referred to as Examples 3 and 4, respectively. In addition, in each sintered compact of Examples 3 and 4 by observing with an electron microscope, the WC particles are fused together to form a three-dimensional network structure, and the ends of the WC particles are rounded. Each was observed.
[0070]
  On the other hand, for comparison, application of a boron compound-containing solutionGrain growth promoterA sintered body having the same composition and dimensions as described above was produced without impregnating the contained solution. That is, after mixing WC and Co in the above proportions to form a cylindrical molded body, the cylindrical molded body is held at 1700 K for 1 hour in a nitrogen atmosphere to obtain a sintered body having a diameter of 30 mm and a length of 30 mm. It was. This is a comparative example.
[0071]
  And after dividing each sintered compact of Examples 1-4 and a comparative example equally into 2 along a length direction and carrying out mirror surface finishing of a cut surface, it goes along the length direction from one bottom to the inside. Vickers hardness was measured. The results are summarized in FIG. From FIG. 3, it is clear that the hardness of the composite material can be remarkably improved by applying the boron compound-containing solution. Therefore, it can be said that by increasing the metal composition ratio, it is possible to improve toughness while ensuring high hardness as compared with the sintered body of the comparative example.
[0072]
  Further, from comparison between Examples 1 and 2 and Examples 3 and 4 in FIG. 3, the hardness is determined to be a porous body rather than a sintered body by applying a boron compound-containing solution to the molded body. And then applying a boron compound-containing solution to the porous body andGrain growth promoterIt is understood that it is higher when the sintered body is formed by immersion in the containing solution.
[0073]
  Further, when the fracture toughness values of the sintered bodies of Examples 1 and 3 and Comparative Example were measured, 18 MPam, respectively.^1/2, 24 MPam^1/2, 14 MPam^1/2Met. That is, the fracture toughness values in the sintered bodies of Examples 1 and 3 were superior to the comparative examples.
[0074]
  Further, bending strength tests were performed on the sintered bodies of Examples 1 and 3 and the comparative example, and the strength at which each sintered body broke (bending strength) was examined. As a result, 4.2 GPa, 4.8 GPa, It was 3.1 GPa.
[0075]
  Furthermore, when the coefficient of friction, thermal conductivity, oxidation resistance, and the like were evaluated, the coefficient of friction decreased in the order of Comparative Example, Example 1, and Example 3, and the others were Example 3 and Example. 1. It decreased in the order of the comparative example. That is, each characteristic was favorable in the order of Example 3, Example 1, and Comparative Example.
[0076]
  From the above results, it is apparent that various properties such as hardness, strength, toughness, friction coefficient, thermal conductivity, and oxidation resistance can be improved by applying the boron compound-containing solution.
[0077]
  Further, the Vickers hardness of the sintered bodies of Examples 1 and 3 and the comparative example was measured while raising the temperature in the atmosphere. The results are shown in FIG. 4 that the sintered bodies of Examples 1 and 3 exhibit relatively high hardness even in a high temperature range.
[0078]
【The invention's effect】
  As explained above,BookAccording to the method for producing a composite material according to the invention, the boron compound-containing solution is applied to the molded body or the porous body, and then the sintering (densification) is performed. During this sintering, boron functions as a grain growth accelerator for the particles of non-oxide ceramics, so that the particles fuse well with each other and are dissolved in the metal. The effect that a composite material having high toughness can be obtained is achieved.
[0079]
  The composite material thus obtained contains a metal whose hardness and strength have been improved by dissolving B in a solid solution of 7 to 30 ppm. Therefore, both the hardness and strength can be improved even when the metal composition ratio is increased in order to improve the toughness of the composite material. And toughness can be significantly improved.
[Brief description of the drawings]
FIG. 1 is a flowchart of a method for manufacturing a composite material according to a first embodiment of the present invention.
FIG. 2 is a flowchart of a method for manufacturing a composite material according to a second embodiment of the present invention.
FIG. 3 is a graph showing the relationship between the distance from the surface and Vickers hardness in sintered bodies of Examples 1 to 4 and Comparative Example.
FIG. 4 is a graph showing the relationship between temperature and Vickers hardness in sintered bodies of Examples 1 and 3 and a comparative example.

Claims (3)

Contains 70 to 97% by weight of at least one non-oxide ceramic selected from the group of WC, TiC, TiN, TaC, NbC, VC, and Cr ₂ C ₃ , and Fe, Ni, Co, and two or more of these 3 to 30% by weight of at least one metal selected from the group of alloys consisting of B, and 7 to 30 ppm by weight of B as a solid solution in the metal, and the particle size of the non-oxide ceramic particles is 5 A method of manufacturing a composite material having a thickness of ˜100 μm and forming a three-dimensional network structure by fusing the particles together, and nitriding the particles of the non-oxide ceramics and bending the ends. ,
A molding step of molding a mixed powder of non-oxide ceramic particles and metal particles into a molded body;
An application step of applying a boron compound-containing solution to all or part of the surface of the molded body;
Sintering the molded body coated with the boron compound-containing solution into a sintered body, and solid-dissolving boron from the boron compound contained in the boron compound-containing solution in the metal ,
I have a,
The boron compound contained in the boron compound-containing solution is titanium boride, molybdenum boride, hexagonal boron nitride or boron carbide,
A method for producing a composite material, characterized in that the atmosphere for obtaining the sintered body is nitrogen . Contains 70 to 97% by weight of at least one non-oxide ceramic selected from the group of WC, TiC, TiN, TaC, NbC, VC, and Cr ₂ C ₃ , and Fe, Ni, Co, and two or more of these 3 to 30% by weight of at least one metal selected from the group of alloys consisting of B, and 7 to 30 ppm by weight of B as a solid solution in the metal, and the particle size of the non-oxide ceramic particles is 5 A method of manufacturing a composite material having a thickness of ˜100 μm and forming a three-dimensional network structure by fusing the particles together, and nitriding the particles of the non-oxide ceramics and bending the ends. ,
A molding step of molding a mixed powder of non-oxide ceramic particles and metal particles into a molded body;
A primary sintering step of sintering the molded body to form a porous body;
Impregnation step of impregnating the inside of the porous body with a solution containing a grain growth accelerator ;
An application step of applying a boron compound-containing solution to all or part of the surface of the porous body;
A secondary sintering step in which the porous body coated with the boron compound-containing solution is sintered to form a sintered body, and boron from the boron compound contained in the boron compound-containing solution is solid-dissolved in the metal. When,
I have a,
The boron compound contained in the boron compound-containing solution is titanium boride, molybdenum boride, hexagonal boron nitride or boron carbide,
A method for producing a composite material, characterized in that the atmosphere for obtaining the sintered body is nitrogen . The manufacturing method according to claim 1 or 2 wherein the grain growth promoting agent contained in the grain growth promoting agent containing solution, Fe, Ni, Co, Mn , Cr, Ti, to one of at least one of Zr or Al A method for producing a composite material.

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