JP4997561B2 - Tool or mold material in which a hard film is formed on a hard alloy for forming a high-hardness film, and a method for producing the same - Google Patents

Description

  The present invention relates to a hard composite material composed of a hard alloy for forming a high-hardness film and a hard film. More specifically, the present invention relates to a surface of a specific hard alloy for forming a high-hardness film that is a base material. The present invention relates to a tool or mold material having improved wear resistance and corrosion resistance, and a hard member such as a tool or a mold, which is made of a hard composite material formed with high adhesion.

  The tool or mold material according to the present invention makes it possible to suppress peeling of a hard film by forming a hard film with a high hardness on a specific hard alloy surface with high adhesion in order to improve wear resistance. For example, when the material is applied to a tool or the like, efficient machining corresponding to high-speed machining conditions or heavy cutting conditions can be realized. It becomes possible. In addition, the present invention can realize oil-free lubrication utilizing the solid lubricity of a hard coating, thereby realizing provision and use of a new hard composite material and highly rigid member considering the environment. It is.

  Conventionally, hard alloys such as cemented carbide in which hard WC particles are bonded with cobalt and cermet alloy in which TiC particles are bonded with nickel are excellent in wear resistance and can be formed by electric discharge machining or grinding. Widely used as tool material and mold material. However, from the viewpoint of emphasizing efficiency in recent machining, high cutting speed and heavy cutting are performed. For this reason, the response is insufficient only with the hard alloy, and a harder film is formed on the surface of the hard alloy. However, since conventional hard alloys are a composite material of pure metal and hard particles, there is a large amount of deformation at high temperatures, and the chemical reaction between the hard film and the metal that is the binder phase proceeds and the film peels off. There was a problem of producing.

  In order to remove such a hard film, improvements have been made by a method in which an insert material having high thermal stability is sandwiched between the film and the hard alloy as a base material. For example, a hard carbon film substrate And the technical development like the formation method (patent document 1) is made | formed. However, even in these methods, it is a fact that a hard film with high adhesion cannot be formed due to the difference in physical properties at high temperatures between the hard film and the hard alloy as a base material. In the field, there has been a strong demand for the development of a new technique capable of forming a hard film with high adhesion on the surface of a hard alloy.

Japanese Patent Laid-Open No. 10-130865

  Under such circumstances, the present inventors have conducted intensive research with the goal of developing a new material capable of solving the problems in the prior art in view of the above-described prior art. We have discovered that it is possible to suppress the generation and adsorption of gases at high temperatures by changing the binder phase of the alloy from pure metal to an intermetallic compound with excellent oxidation resistance and densifying it during the sintering process. The present invention has been completed. That is, the present invention focuses on a hard alloy as a base material for forming a hard film, and uses a new hard alloy with improved oxidation characteristics and mechanical characteristics at high temperatures to increase the adhesion of the hard film. It was made.

  In order to form a hard film with good adhesion, the present invention cleans the surface of the base material so that the film is not peeled off by heat generated in the process of forming the film, and suppresses deformation, thereby An object of the present invention is to provide a tool or mold material in which a high hardness film is formed on the surface of a high hardness film forming alloy, which is a material, and the wear resistance and corrosion resistance are improved.

The present invention for solving the above-described problems comprises the following technical means.
(1) A hard-adhesive composite material having a hard alloy as a base material and a structure in which a hard film is formed on the surface of the hard alloy and having no problem of film peeling,
The hard alloy, the hard particles consisting of carbide, iron and aluminum iron as a main component - made of a high hardness coating forming hard alloy bonded by an aluminum alloy binder phase, said hard coating, containing-carbon Ri Do a hard coating that, in the high-hardness film forming hard alloy, iron binding phase - aluminum alloy state, and are not burned synthesized during pressurization sintering, iron - the amount of aluminum to aluminum alloy , Ri 37 wt% der from 12 wt%, hard high hardness film forming hard alloy, characterized in that you have been densified to the 5% porosity by pressure sintering or smaller porosity Composite material.
(2) hard coating, diamond, diamond-like carbon, boride carbon, silicon carbide, titanium carbide, titanium carbonitride, hard according to at least one consists of the to be inner shell selected carbonitride zirconium beam (1) Composite material.
(3) A hard member comprising the hard composite material according to (1) or (2).
(4) The hard member according to (3), wherein the hard member is a tool or a mold.
(5) hard and hard particles consisting of carbide, iron powder, aluminum powder were mixed by pressure sintering it to form a high hardness film forming hard alloy, containing carbon on the surface of the hard alloy A method for producing a hard composite material that forms a film and produces a highly adhesive hard composite material that has no problem of peeling of the film ,
In the high-hardness film forming hard alloy, iron - a binding phase of aluminum alloy, these during pressure sintering to form by combustion synthesis, iron - the amount of aluminum to aluminum alloy, 12 wt% to 37 wt% der is, the production method of the hard composite material characterized the densification child in the 5% porosity by pressure sintering or smaller porosity.
(6) to the surface of the hard metal to form a diamond, diamond-like carbon, boride carbon, silicon carbide, titanium carbide, titanium carbonitride, a hard film comprising at least one is inner shell selected carbonitride zirconium arm The method according to (5) above.

  Next, the present invention will be described in more detail. The present invention relates to a hard composite material in which a hard film is formed on the surface of a hard alloy as a base material, and the hard alloy is at least one hard particle selected from carbide, nitride, boride, and oxide. Is made of a hard alloy for forming a high-hardness film that is bonded with an alloy mainly composed of iron and aluminum, and the hard film contains at least one element selected from the group consisting of carbon, nitrogen, boron, and oxygen. It is characterized by comprising.

  First, the hard coating and the film forming method will be described. The film formed on the hard alloy having high hardness used in the present invention is a hard film containing at least one element of carbon, nitrogen, boron, and oxygen, and is generally known as a hard inorganic material. Materials can be used.

  Since these inorganic materials are excellent in heat resistance, it is necessary to use a film forming process using high energy in order to form a film. In the present invention, for example, sputtering that ionizes argon using high frequency and collides with an inorganic material target to form a film, reactivity that evaporates metal by a high heat source such as an electron beam or an arc and reacts with an atmospheric gas It is possible to produce a film using a method such as sputtering or a CVD method in which a reactive gas is decomposed with heat to deposit while synthesizing a target inorganic substance.

  In general, it is known that it is effective to form a film on the surface of a base material at a high temperature in order to produce a film having excellent adhesion to a hard alloy as a base material. In order to improve the adhesion to the base material, it is effective to form a film containing a metal on the surface of the base material. In the present invention, a metal, an organic substance or an inorganic substance is used as a film forming aid. be able to.

  Specific examples of the material for the hard coating include diamond, diamond-like carbon, carbon boride, silicon carbide, titanium carbide, titanium carbonitride, zirconium carbonitride, titanium nitride, zirconium nitride, hafnium nitride, and titanium nitride aluminum. One or more selected from aluminum oxide are exemplified. However, it is not limited to these, and can be used in the same manner as long as they have the same effect.

  Next, a hard alloy for forming a high hardness film and a method for producing the same will be described. As the hard alloy used in the present invention, those containing at least one kind of hard particles among carbide, nitride, boride and oxide can be used as the hard particles. In general, these hard particles are used as a hard alloy by being bonded by a pure metal such as cobalt or nickel or a solid solution thereof. However, pure metals or their solid solutions react with carbon, nitrogen, boron, and oxygen, which are light elements constituting the hard particles, at high temperatures to generate a fragile phase. Further, in the process of forming a high hardness film, a partial high temperature is generated, so that a reaction between the light element constituting the film and the binder phase of the hard alloy occurs.

  Therefore, in the present invention, it is indispensable to use an alloy obtained by adding aluminum to iron as a metal for bonding hard particles. Since iron has a stronger binding force with light elements than cobalt and nickel, the chemical reaction between the hard coating and the binder phase proceeds easily to produce a compound. When iron is used as the binder phase of a hard alloy, A high hardness film cannot be formed. Moreover, since aluminum has a low bonding strength with hard particles, it is impossible to produce a dense and high-strength hard alloy. However, an alloy of iron and aluminum can suppress the formation of the compound by the above chemical reaction while maintaining a high bonding force with the light element constituting the film, and thus can solve these problems. This makes it possible to produce a tool or mold material having high adhesion to a hard film containing carbon, nitrogen, boron, and oxygen.

  As described above, the hard particles that are the material of the hard alloy include at least one kind of hard particles of carbide, nitride, boride, and oxide, specifically, for example, tungsten carbide, tantalum carbide, carbonized Examples include titanium, chromium carbide, vanadium carbide, zirconium carbide, silicon carbide, silicon nitride, titanium boride, and aluminum oxide. However, it is not limited to these, and can be used in the same manner as long as they have the same effect.

  The hard alloy can be produced by homogeneously mixing the hard particles, iron powder, and aluminum powder, followed by pressure sintering. The sizes of the hard particles, iron powder, and aluminum powder are not particularly limited, but the iron powder is preferably as fine as possible. For example, a fine powder of about 1 to 10 micrometers is preferable. The mixing method of these powders is not particularly specified, but general mixing methods such as mortar mixing, vibration ball mill, rolling ball mill, planetary ball mill, and attritor can be used.

  The molding method is not particularly limited, and pressure molding using a graphite or ceramic jig can be used. The heating method is not particularly limited, but since aluminum dissolves during heating, it is preferable to heat under pressure in order to produce a dense molded body. Since aluminum is easily oxidized, heating is preferably performed in a vacuum, and current heating under pressure using a graphite jig is a more preferable sintering method. The heating temperature is preferably 900 to 1300 ° C. in order to obtain a homogeneous iron aluminum compound. Immediately after aluminum is dissolved, iron and aluminum react to synthesize an iron-aluminum compound, which is further heated to form an ordered alloy phase and form a stronger bonded phase.

  In the heating step, a hard alloy densified to 5% or less is produced. Moreover, the iron-aluminum alloy which is a binder phase is formed by combustion synthesis at the time of sintering. As a result, it is possible to produce a hard alloy having high adhesion with the hard coating, while suppressing the formation of the compound while maintaining a high binding force with the light elements constituting the coating. .

  An iron-aluminum alloy serving as a binder phase changes in strength, hardness, and magnetism depending on the amount of aluminum. In order to adhere a high hardness film to the surface of the hard alloy as the base material, it is necessary to control the coefficient of thermal expansion, corrosion resistance, hardness, etc. of the base material, and the aluminum content of the iron-aluminum alloy is 12% by weight. It is possible to control by adjusting to 37% by weight. If the amount of aluminum is 12% by weight or less, the corrosion resistance is poor, and a fragile phase is generated in the process of forming a high hardness film. On the other hand, if the amount of aluminum is 37% by weight or more, pores remain in the sintered body. The adhesion of the film decreases.

  In the conventional hard materials, various attempts have been made to produce composite materials in which a hard film is further formed on the surface of the hard alloy. However, since hard alloys are composite materials of metal and hard particles, the amount of deformation at high temperatures is low. In addition, the chemical reaction between the hard film and the metal that is the binder phase in the hard alloy has progressed, and there has been a problem that the film is inevitably peeled off. In contrast, in the present invention, since an iron-aluminum alloy is used as the binder phase of the hard alloy, the chemical reaction between the hard coat and the binder phase is suppressed while maintaining a high binding force with the light elements constituting the coat. Therefore, it is possible to produce and provide a high-adhesion hard composite material and a hard member that have high adhesion to a hard film and have no problem of film peeling.

According to the present invention, the following effects can be obtained.
(1) A hard composite material in which a hard film is formed on the surface of a hard alloy with high adhesion can be provided.
(2) A tool or mold material with improved wear resistance and corrosion resistance can be provided.
(3) Longer life of the member can be achieved by suppressing the peeling of the hard coating formed to improve the wear resistance.
(4) By applying the hard composite material to a tool or a die, it is possible to realize efficient machining corresponding to high-speed machining conditions or heavy cutting conditions.
(5) Oil-free lubrication utilizing the solid lubricity of the hard coating can be realized.
(6) It is possible to provide a new technology relating to a hard material and a hard member capable of improving the problem of peeling of the hard film.
(7) The grinding fluid generated during grinding of the hard alloy can be made environmentally friendly.
(8) By controlling magnetism and non-magnetism, it is possible to prevent or promote the attachment of machining waste to a tool or a mold.

  EXAMPLES Next, although this invention is demonstrated concretely based on an Example, this invention is not limited at all by the following Examples.

(1) Preparation of hard alloy Iron powder (manufactured by Kojundo Chemical Laboratory Co., Ltd., 99.9% by weight), aluminum powder (manufactured by Kojundo Kagaku Kenkyusho Co., Ltd., 99.9 wt%), cobalt powder ( High Purity Science Laboratory Co., Ltd., 99.9% by weight) and tungsten carbide powder (Nippon Shin Metal Co., Ltd., 99%, 2.5 microns) were mixed with FeAl (24.4% by weight Al) -75. After blending to make volume% WC and Co-75 volume% WC, mixing in an automatic mortar to make a mixture, filling the mixture in a graphite jig, then, this is electrified pressure sintering Sintering was performed at 1200 ° C. in the apparatus. The porosity of the obtained sintered body was 2% or less.

(2) Formation of hard film The surface of these sintered bodies was mirror-finished, and DLC coating was performed by CVD. The film thicknesses of the obtained DLCs were all 0.5 microns, and when the films formed by Raman spectroscopy were measured, it was confirmed that all the profiles showed typical DLC (FIG. 1). . Further, when the vicinity of the interface was observed with a scanning electron microscope, no phase that was considered to be a reaction product was observed (FIG. 2).

(3) Evaluation of adhesion A scratch test was performed on these materials in order to evaluate the adhesion between the base material and the hard film. The critical load in the case of using a material containing FeAl as a base material was 88.2 mN, which was about 1.3 times that of a material containing Co as a base material (FIG. 3). In the Fe—C system and the Co—C system, the value of formation enthalpy (ΔH) representing the degree of ease of bonding (or alloying) between elements is ΔH _Fe—C = + 6 (kJ / mol), ΔH _Co-C = + 16 (kJ / mol), and the binding force is larger between Fe-C. Therefore, it is considered that the adhesion strength with the film was large.

  FeAl (24.4 wt% Al) -75 vol% WC was prepared at a sintering temperature of 1100 ° C. in the same manner as in the above example. As a result, the porosity of the obtained sintered body was 8% (FIG. 4). Next, DLC coating was performed on the surface of the sintered body to prepare a hard composite material in which a hard film having a thickness of 0.5 microns was formed on the surface of the hard alloy. When the adhesion between the film and the base material was evaluated by a scratch test, a critical load of 34.1 mN was obtained. In this way, the adhesion strength to the film was smaller than that of the densified material because the adhesion area between the base material and the film was small, and the gas adsorbed in the voids diffused to the interface, resulting in adhesion. This is thought to be due to a decrease in. In the present invention, it has been found that a material densified to a porosity of 5% or less is preferably used as a material that can be expected to have a particularly high adhesion strength.

  As described above in detail, the present invention relates to a tool or mold material in which a hard film is formed on a hard alloy for forming a high-hardness film, and a method for producing the tool or mold material. , Which contributes to the extension of the service life of the material by suppressing the peeling of the hard coating formed to improve wear resistance. For example, when applied to tools, high-speed machining conditions And efficient machining corresponding to heavy cutting conditions. Further, the present invention can realize oil-free lubrication utilizing the solid lubricity of the hard coating, and can provide a member that takes the environment into consideration.

The Raman spectroscopic analysis result of the DLC film produced on the FeAl-75 volume% WC base material and the Co-75 volume% WC base material is shown. It is the result of the cross-sectional observation of a DLC film and a base material with the scanning electron microscope, (a) shows a FeAl-75 volume% WC base material, (b) shows a Co-75 volume% WC base material. The result of the scratch test with respect to the DLC film produced on the FeAl-75 volume% WC base material and the Co-75 volume% WC base material is shown. The result of the scratch test with respect to the DLC film produced on the FeAl-75 volume% WC base material which is not fully densified is shown.

Claims (6)

A hard alloy that is a base material, and a hard adhesive material having a structure in which a hard film is formed on the surface of the hard alloy and having no problem of film peeling,
The hard alloy, the hard particles consisting of carbide, iron and aluminum iron as a main component - made of a high hardness coating forming hard alloy bonded by an aluminum alloy binder phase, said hard coating, containing-carbon Ri Do a hard coating that, in the high-hardness film forming hard alloy, iron binding phase - aluminum alloy state, and are not burned synthesized during pressurization sintering, iron - the amount of aluminum to aluminum alloy , Ri 37 wt% der from 12 wt%, hard high hardness film forming hard alloy, characterized in that you have been densified to the 5% porosity by pressure sintering or smaller porosity Composite material. Hard film, diamond, diamond-like carbon, boride carbon, silicon carbide, titanium carbide, titanium carbonitride, hard composite material according to claim 1 comprising at least one member inner shell selected carbonitride zirconium beam.   A hard member made of the hard composite material according to claim 1.   The hard member according to claim 3, wherein the hard member is a tool or a mold. Forming a hard particles consisting of carbide, iron powder, aluminum powder were mixed, which was prepared high hardness film forming hard alloy by pressure sintering, the hard film containing carbon on the surface of the hard alloy A method of manufacturing a hard composite material for producing a highly adhesive hard composite material that does not have a problem of film peeling ,
In the high-hardness film forming hard alloy, iron - a binding phase of aluminum alloy, these during pressure sintering to form by combustion synthesis, iron - the amount of aluminum to aluminum alloy, 12 wt% to 37 wt% der is, the production method of the hard composite material characterized the densification child in the 5% porosity by pressure sintering or smaller porosity. The surface of the hard alloy, diamond, diamond-like carbon, boride carbon, silicon carbide, claim forms titanium carbide, titanium carbonitride, a hard film comprising at least one is inner shell selected carbonitride zirconium arm 5 The method described in 1.