KR100755882B1 - New Ti-based solid-solution cutting tool materials - Google Patents

Abstract

In the present invention, there is no core structure consisting of carbides, carbonitrides, or mixtures of two or more metals selected from the group IVa, Va, and VIa metals in the periodic table, including titanium, and having nanocrystal grains of 100 nm or less. A solid solution powder characterized in that it is completely solid solution, a powder for cermet comprising the same, a ceramic sintered body sintered the solid solution powder, a cermet sintered the powder for the cermet, and has a nano-size IVa of the periodic table, Mixing, mixing and pulverizing oxides and carbon powders or carbon sources of two or more metals selected from Va, and Group VIa metals, including titanium; And reducing and carbonizing or reducing, carbonizing, and nitriding the mixed powder or pulverized powder (S2); a method for producing a solid solution powder, comprising a powder for cermet comprising the solid solution powder The manufacturing method, etc. are disclosed. According to the present invention, by providing a completely solid solution phase in the fine structure of TiC-based or Ti (CN) -based composite powder, it improves the hardness and toughness of ceramics without a metal binder or the toughness of a cermet material in which the metal binder is present. Significantly improved, the ability to sinter directly without additional mixing, and the good overall mechanical properties make it possible to replace WC-Co cemented carbide materials, providing the effect of providing hard or tough cutting tools. .

Carbon powder, Nano size, Carbonitride, Carbide, Core structure, Complete solid solution, High toughness, Hardness, Cermet

Description

New Ti-based solid-solution cutting tool materials

1A is an XRD image analysis result of (Ti, W) C solid solution powder containing 15 wt% WC according to the present invention.

Figure 1b is an XRD image analysis of the powder for (Ti, W) C-Ni cermet containing 30wt% WC according to the present invention.

Figure 1c is a result of XRD analysis of the powder for (Ti, W) (CN) -Ni cermet containing 30wt% WC according to the present invention and the ratio of C and N is 3: 1.

Figure 2a is a SEM photograph showing the shape of the powder for (Ti, W) C-Ni cermet containing 15wt% WC according to the present invention.

Figure 2b is a TEM photograph showing the shape of the powder for (Ti, W) C-Ni cermet containing 15wt% WC according to the present invention.

Figure 3a is a powder for (Ti, W) C-Ni cermet containing 15wt% WC and powder for (Ti, W) C-Ni cermet containing 30wt% WC according to the present invention 1 at 1510 ℃ It is FE-SEM photograph of time sintered.

FIG. 3b is a powder for (Ti, W) (CN) -Ni cermet with 15 wt% WC and a ratio of C and N, and 30 wt% WC with a ratio of C and N FE-SEM photograph of three-to-one (Ti, W) (CN) -Ni cermet powders sintered at 1510 ° C for 1 hour.

FIG. 4A is a FE-SEM photograph of a sintered powder for (Ti, W) C-Ni cermet including 15 wt% of WC in a nitrogen atmosphere according to the present invention at 1510 ° C. for 1 hour.

Figure 4b is a FE-SEM photograph of the surface portion of the sintered powder for (Ti, W) C-Ni cermet containing 30wt% WC in a nitrogen atmosphere by 1 hour at 1200 ℃ according to the present invention.

5 is a FE-SEM photograph of the TiN coating using PVD after sintering the powder for (Ti, W) C-Ni cermet including 15 wt% of WC at 1510 ° C. for 1 hour.

6A is a FE-SEM photograph of a sintered mixture of TiC-Ni and WC-Ni at 1510 ° C. for 1 hour according to the present invention.

6B is a FE-SEM photograph of a sintered mixture of Ti (CN) -Ni and Mo ₂ C-Ni at 1510 ° C. for 1 hour according to the present invention.

FIG. 7 is a FE-SEM photograph of a sintered mixture of (Ti, W) (CN) -Ni and 30 wt% of Ti (CN) -Ni at 1510 ° C. for 1 hour.

The present invention relates to a solid solution powder, ceramics sintered solid solution powder, cermet powder containing solid solution powder, cermet sintered powder for cermet, and a method for producing the same. More specifically, it is applied to high-speed cutting tool materials and mold materials used in the mechanical industry, such as machine manufacturing and automobile industry, and ceramics sintered solid solution powder and solid solution powder which can improve overall mechanical properties and especially toughness and hardness. The present invention relates to a powder for cermet containing solid solution powder, a cermet sintered powder for cermet, and a method for producing the same.

 In the present invention, nano size means a size of 100 nm or less, as is generally known.

The main cutting tools or wear-resistant tools used in the metal cutting process required for the mechanical industry include WC cemented carbide, TiC or Ti (CN) based cermet alloys, other ceramics or high speed steels.

Among them, the cermet is generally composed of metals such as TiC, Ti (CN), which are hard phases, and Ni, Co, Fe, which are bonded phases, and carbides, nitrides, and nitrides of Group IVa, Va, and Group VIa metals in the periodic table. Ceramic-metal composite sintered compact containing carbonitride and the like as an additive.

That is, the cermet mixes hard ceramic powders such as WC, NbC, TaC, Mo ₂ C, and metal powders such as Co and Ni, which are combined for bonding them, in addition to TiC, Ti (CN), and the like, and vacuum them. It is manufactured by sintering in a hydrogen atmosphere.

TiC and Ti (CN) have been applied to many fields as excellent high strength materials. In particular, TiC has a very high hardness (Vicker's hardness) of 3,200kg / mm ² , a very high melting point of 3,150 to 3,250 ° C, and a relatively excellent oxidation resistance up to 700 ° C. Because of its excellent properties, it has been widely used as a substitute for WC-Co alloys as a material for high-speed cutting tools.

However, when the cermet is manufactured using the TiC, a binder phase metal such as Ni is used as the liquid metal during sintering. In this case, since the wetting angle is larger than that of the WC-Co combination, Rapid grain growth occurs, resulting in a drop in toughness.

Nevertheless, in 1956, Ford Motor of the United States first mass-produced TiC-Mo ₂ C-Ni cermets, although their toughness was not significantly improved, they were machined as hard tool materials for precision machining. Used in semi-finishing and finishing.

In the 1960s and 1970s, attempts were made to add various kinds of elements to improve toughness, which is the biggest weakness of the TiC-Ni cermet system.

However, by adding TiN to TiC in the 1970s, Ti (CN), which is a thermodynamically more stable phase, was formed, thereby improving the toughness to some extent.

That is, Ti (CN) has a finer structure than TiC, so the toughness could be improved, and in addition, chemical stability and mechanical impact resistance could be improved.

On the other hand, many added carbides, such as WC, Mo ₂ C, TaC, NbC, etc. have been used to improve toughness, and Ti (CN) -M1C-M2C-... -Ni / Co type products are commercially available.

When the addition carbide is applied to improve the toughness, the general microstructure of the TiC-based or Ti (CN) -based cermet sintered body is observed as a core / rim structure. The hard phase of such a core structure is Ni, A binding phase such as Co is surrounded.

The core of the core structure is a structure having high hardness as TiC or Ti (CN) which is not dissolved in a metal binder (binder: Ni, Co, etc.) liquefied during sintering.

On the other hand, the surrounding rim tissue surrounding these cores is represented by a solid-solution (Ti, M1, M2…) (CN) between the core components TiC or Ti (CN) and the added carbides. It is a tissue with high toughness rather than hardness.

Thus, through the formation of the rim structure, the cermet solved the problem of toughness, which is a fatal weakness of the simple cermet such as TiC-Ni or Ti (CN) -Ni, to some extent.

However, in the case of the cermet having the concentric structure, there is still a problem that the toughness is lower than that of the cemented carbide of WC-Co, and thus it has not yet completely replaced WC-Co.

Thus, attempts to develop improved toughness through the formation of unemployed, fully employed forms have been steadily made by Japanese tool companies such as Sumitomo, Kyocera, and researchers from the European Union of NATO. come.

However, solid solution phases are formed during sintering, and since the amount formed is related to the sintering temperature and time, it is not possible to obtain a cermet consisting entirely of solid solution, and the solid solution powder produced using the same or the poles which are still achieving substantial toughness No microstructures have been provided.

Accordingly, the present invention has been made to solve the above problems, the object of the present invention is to solve the problem of low toughness according to the high hardness of the conventional TiC-based, Ti (CN) -based cermet, TiC-based or Ti By providing a fully solid solution phase having no core structure in the fine structure of the (CN) -based composite powder, the toughness of the cermet material can be substantially improved, and the overall mechanical properties are also excellent, thus WC-Co cemented carbide material A solid solution powder, a manufacturing method thereof, a powder for cermet containing the solid solution powder, a manufacturing method thereof, and a ceramic sintered body sintered the solid solution powder, which enables the production of a high hardness, high toughness cutting tool in place of It is to provide a cermet using the powder for the met.

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The present invention relates to a solid solution powder, a manufacturing method thereof, a powder for cermet including the solid solution powder, a manufacturing method thereof, and a ceramic sintered body obtained by sintering the solid solution powder. Compared to the conventional toughness of Ti- or Ti (CN) -based cermets, the hardness and toughness are significantly improved by providing a completely solid phase that does not exhibit a core structure in the microstructure. It achieves the effect of replacing WC-Co cemented carbide materials and providing high hardness and toughness cutting tools.

In the present invention, in order to achieve the above object, carbides, carbonitrides, or mixtures of two or more metals selected from the group IVa, Va, and Group VIa metals, including titanium, in the periodic table, and have nanocrystals of 100 nm or less. It provides a solid solution powder characterized in that the complete solid solution.

(I) carbides, carbonitrides, or mixtures thereof of one or more metals from Groups IVa, Va, and VIa metals of the periodic table, and (ii) at least one of Ni, Co, and Fe Provided is a powder for agglomerated cermets having nanocrystal grains of 100 nm or less.

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The cermet powder in the cermet powder according to the present invention comprises (i) carbides, carbonitrides, or mixtures thereof of two or more metals selected from the group IVa, Va, and VIa metals in the periodic table, including titanium. And (ii) aggregates comprising at least one metal of Ni, Co and Fe, which are fully solid solutions and have aggregates of up to 100 nm.

The present invention provides a ceramic by sintering a solid solution powder that is an aggregate having nanocrystal grains of 100 nm or less, including carbides, carbonitrides, or mixtures of one or more metals from Group IVa, Va, and VIa metals in the periodic table.

(I) carbides, carbonitrides, or mixtures thereof of one or more metals from Groups IVa, Va, and VIa metals of the periodic table, and (ii) at least one of Ni, Co, and Fe The powder for cermet, which is an aggregate having nanocrystal grains of 100 nm or less, is sintered to provide a cermet.

The powder for cermet in the cermet by the present invention comprises (i) carbides, carbonitrides, or mixtures thereof of two or more metals selected from the group IVa, Va, and Group VIa metals, including titanium, in the periodic table; (ii) an aggregate comprising at least one metal of Ni, Co and Fe, which is a fully solid solution and has an aggregate of nanocrystals of 100 nm or less.

In the cermet according to the present invention, the cermet is a cermet of TiC-Me or Ti (CN) -Me (e is one or two or more bonding phases selected from the group consisting of Ni, Co and Fe) having nanocrystals of 100 nm or less. WC-Me, Mo ₂ C-Me, TaC-Me, NbC-Me, ZrC-Me, and HfC-Me, both of which have nanocrystal grains of 100 nm or less, and Me is one selected from the group consisting of Ni, Co, and Fe Or a sintered body of a mixture of powders for cermets selected from the group consisting of two or more combined phases) which have a core of Ti (CN).

In the cermet according to the present invention, the cermet is a cermet of TiC-Me or Ti (CN) -Me (e is one or two or more bonding phases selected from the group consisting of Ni, Co and Fe) having nanocrystals of 100 nm or less. Powders and (i) carbides, carbonitrides, or mixtures thereof of two or more metals selected from the group IVa, Va, and VIa metals in the periodic table, including titanium; and (ii) at least one of Ni, Co, and Fe. It is a sintered compact of the mixture of the powder for cermets which is an aggregate of the completely solid solution which has a nanocrystal grain below 100 nm containing a metal.

In the cermet according to the present invention, the cermet has only a hard phase of TiC, Ti (CN), (Ti, M1, M2 ..) C or (Ti, M1, M2 ..) (CN) on the surface of the cermet. This hard phase is formed together with the sintering of the powder for cermet by controlling the amount and time of nitrogen introduced into the furnace during the sintering process.

In the ceramic according to the present invention, the ceramic is formed by TiC-Me, Ti (CN) -Me, (Ti, M1, M2 ..) C-Me formed by CVD, PVD or the like after sintering the solid solution powder on the surface of the ceramic. (Ti, M1, M2 ..) (CN) -Me (Me is one or more of two or more binding phases selected from the group consisting of Ni, Co and Fe) further comprises a toughened coating layer.

In the cermet according to the present invention, the cermet further includes a reinforced coating layer of TiC, TiN, Ti (CN), TiAlN or TiAlCrN formed by CVD or PVD after sintering the powder for cermet on the surface of the cermet. The met is sintered in a vacuum, argon or nitrogen atmosphere to have a solid or bonded phase on the surface of the cermet.

According to the present invention, a step of mixing an oxide of two or more metals selected from the group IVa, Va, and Group VIa in the periodic table having a nano size, including titanium with a carbon powder or a carbon source according to a desired composition (S1-1). And; reducing and carbonizing the oxide and the carbon powder or the powder mixed with the carbon source (S2).

In the method according to the present invention, the step (S1-1) further includes pulverizing a mixed powder of an oxide and a carbon powder or a carbon source.

According to the present invention, nanoscales of 100 nm or less after mixing oxides of two or more metals selected from group IVa, Va, and Group VIa metals in the periodic table, including titanium, with a carbon powder or carbon source, depending on the desired composition Or pulverizing to an amorphous state (S1-2); It provides a method for preparing a solid solution powder comprising a; and reducing and carbonizing the oxide and carbon powder or powder mixed with a carbon source (S2).

According to the present invention, (i) an oxide having at least one metal component of nano size selected from Ni, Co and Fe, (ii) an oxide having at least one component of nano size selected from Group IVa, Va, and Group VIa metals in the periodic table; (iii) mixing (S1-3) the carbon powder or carbon source according to the desired composition and reducing and carbonizing the mixed powder of the oxide [(i) and (ii)] and the carbon powder or carbon source [(iii)]. It includes the powder manufacturing method for cermet using the method containing the step (S2).

According to the invention step (S1-3) comprises (i) an oxide having at least one metal component of nano size selected from Ni, Co and Fe, and (ii) titanium from Group IVa, Va, and Group VIa metals in the periodic table. Oxides having two or more components of selected nanosize and (iii) a mixture of carbon powders or carbon sources according to the desired composition.

According to the present invention, step (S1-3) further includes a step of crushing the mixed powder of the oxides [(i) and (ii)] and the carbon powder or the carbon source [(iii)].

According to the present invention, (i) an oxide having at least one metal component of micron size selected from Ni, Co and Fe, (ii) an oxide having at least one component of micron size selected from Group IVa, Va, and Group VIa metals in the periodic table; (iii) mixing the carbon powder or the carbon source according to the desired composition and pulverizing the mixed powder of the oxide [(i) and (ii)] and the carbon powder or the carbon source [(iii)] to a nano size or amorphous state. (S1-4); and a method for producing a powder for cermet comprising the step of reducing and carbonizing (S2) a mixed powder of an oxide [(i) and (ii)] and a carbon powder or a carbon source [(iii)]. to provide.

According to the invention step (S1-4) comprises (i) an oxide having at least one metal component of micron size selected from Ni, Co and Fe, and (ii) titanium from Group IVa, Va, and Group VIa metals in the periodic table. An oxide having two or more components of selected micron size, and (iii) a mixing process of a carbon powder or carbon source according to the desired composition and a mixture of oxides [(i) and (ii)] and carbon powder or carbon source [(iii)]. Pulverizing the powder to a nano size or amorphous state.

According to the invention step (S2) further comprises a nitriding process in addition to the reduction and carbonization process of the oxide powder and carbon powder or carbon source.

According to the present invention step (S2) is a reduction and carbonization process is carried out at the same time in a nitrogen atmosphere in a vacuum or hydrogen, CH ₄ , CO / CO ₂ atmosphere at 1000 to 1300 ℃ 3 hours or less.

According to the present invention, the method comprises sintering a solid solution powder which is a carbide, carbonitride, or mixture thereof, an aggregate having nanocrystal grains of 100 nm or less, selected from group IVa, Va, and Group VIa metals in the periodic table. That is, a method of manufacturing a ceramic is provided.

According to the present invention, (i) a carbide, carbonitride, or mixture thereof of one or more metal components selected from Group IVa, Va, and Group VIa metals of the periodic table, and (ii) one or more metals selected from Ni, Co and Fe Provided is a method for producing a cermet, that is, a method comprising the step of sintering a powder for cermet, which is an aggregate having nano grains of 100 nm or less.

According to the present invention, all of the powders for cermets of TiC-Me, or Ti (CN) -Me (Me is one or two or more bonding phases selected from the group consisting of Ni, Co, and Fe) having nanocrystals of 100 nm or less and both are 100 nm. WC-Me, Mo ₂ C-Me, TaC-Me, NbC-Me, ZrC-Me and HfC-Me having the following nano grains (Me is one or more binding phases selected from the group consisting of Ni, Co and Fe) A mixed powder of powder for one or more selected cermets from the group consisting of) is sintered.

According to the present invention, the powder for cermet of TiC-Me or Ti (CN) -Me (Me is at least one or two bonding phases selected from the group consisting of Ni, Co and Fe) having nanocrystals of 100 nm or less and (i 10 nm or less nanoparticles containing carbides, carbonitrides, or mixtures of at least two metals, including titanium, from Group IVa, Va, and VIa metals in the periodic table, and (ii) at least one metal of Ni, Co, and Fe. The mixed powder of the powder for cermet, which is an aggregate of a solid solid having crystal grains, is sintered.

In the process of the present invention, by controlling the amount and time of nitrogen introduced into the furnace during the sintering process, TiC, Ti (CN), (Ti, M1, M2 ..) C or (Ti, M1 And forming a hard phase of M2 ..) (CN) only on the cermet surface.

In the process of the present invention, sintering is carried out in a vacuum, argon or nitrogen atmosphere so that the surface of the cermet has a high solid phase or a large number of binder phases, and after sintering of the powder for cermet, CVD or PVD is applied on the surface of the cermet. It further comprises the step of forming a reinforcement coating layer of TiC, TiN, Ti (CN), TiAlN or TiAlCrN.

In the process of the present invention, after sintering the solid solution powder, TiC-Me, Ti (CN) -Me, (Ti, M1, M2 ..) C-Me or (Ti, M1, M2 ..) (CN) -Me further comprises forming a toughening coating layer of (Me is one or more binding phases selected from the group consisting of Ni, Co and Fe).

In the text, uppercase letters such as W, M1, M2 .. and lowercase letters such as w, m1, m2 .. are used simultaneously. This means that lowercase letters w, m1, m2 .. are less than uppercase letters W, M1, M2 ....

The solid solution powder according to the present invention, the cermet powder containing the solid solution powder, and the cermet using the cermet powder, the solid solution powder or the cermet powder containing the binding phase metal therein is 100 nm or less nanocrystal grain Thus, it becomes possible to provide a complete employment without having a concentric structure, thus substantially improving the toughness of the provided cermet.

According to the present invention, the process for preparing the solid solution powder and the cermet powder consists of two steps.

The first step for the preparation of a solid solution powder is to mix oxides and carbon powders or carbon sources of two or more metals selected from the group IVa, Va, and VIa metals of the periodic table with nano size, according to the desired composition, or Mixing and pulverizing (S1-1).

Alternatively, the first step to prepare a solid solution powder is to mix oxides of a metal selected from the group IVa, Va, and VIa metals of the periodic table with a micron size with a carbon powder or carbon source and nanosize the mixture. Or a crushing step (S1-2) to be amorphous.

In the first step, it is possible to use nano-sized mixed oxides and carbon powders or carbon sources to produce carbide or carbonitride solid solution powders with a completely solid solution phase. However, micron-sized mixed oxides and carbon powders or carbon sources can be mixed and pulverized into nanoscale nanoscales using high energy ball milling.

For example, in order to prepare a solid solution powder based on TiC having a nano size, Ti in a metal of Groups IVa, Va, and VIa in a periodic table such as nano sized TiO ₂ , nano sized WO _3, etc. Except for the oxide of any one or two metals selected, and carbon powder or carbon source (S1-1). Then, after that, if necessary, the powder of the nano-sized oxides and the carbon powder may be further ground.

When not using a metal oxide already nano-sized prior to mixing and / or milling, any one or more selected except for Ti in Groups IVa, Va, and VIa of the micron-sized TiO ₂ and micron-sized periodic tables The oxides of the metals are mixed with the carbon powder or carbon source, and the mixed powders are ground to an amorphous nano size.

The amount to be mixed may be appropriately selected depending on the composition of the predetermined solid solution powder. The high energy ball mill described above may also be used in the grinding process. According to the present invention, nano-sized grains or amorphous powders were easily produced by only high energy ball milling.

On the other hand, the first step for the preparation of powder for cermets is an oxide and carbon powder or carbon source of two or more metals selected from the group IVa, Va, and Group VIa metals of the periodic table having a nano size; And mixing and pulverizing the oxide mixture of nanophase sized powders of the bonded phases such as nickel, cobalt and iron and the mixture as needed.

Or a first step for preparing a powder for cermets is an oxide and carbon powder or carbon source of two or more metals selected from the group IVa, Va, and Group VIa metals of the periodic table, having a micron size; And oxide mixing of the powders of the bonded phases, such as nickel, cobalt and iron, having a micron size, and grinding to make them nanoscale or amorphous.

Including titanium from Group IVa, Va, and Group VIa metals in the periodic table having nano-sized oxides and nano-sized oxides of bonding phase metals such as nickel, cobalt and iron for preparing powders for cermets according to the invention. Oxide of the metal selected; And a step of mixing the carbon powder or the carbon source according to the desired composition and further proceeding the grinding step as necessary.

Nano or micron-sized oxide and carbon powders of metals selected from the group IVa, Va, and VIa metals in the periodic table when using oxides of the bonding phase, such as nickel, cobalt and iron, having a micron size here Or a carbon source; is mixed with a micron-sized metal-bonded phase oxide to form a nano-scale or amorphous state.

According to the first step, a uniform unstructured structure can be obtained with a complete solid solution without a concentric structure. Furthermore, the cermet can be obtained by directly sintering the powder for the cermet without further processing.

The second step to prepare the solid solution powder and the powder for the cermet then involves a reduction and carbonization process. If necessary, the second step includes reduction, carbonization and nitriding (S2).

For example, the mixed and milled powder is prepared as a solid solution composed of completely solid solution with nano grains after reduction in vacuum or hydrogen, CH ₄ , CO / CO ₂ atmosphere and after carbonization and nitriding processes. In addition, for powders for cermets, aggregates are prepared that have nanocrystals and are completely solid solution.

Furthermore, in the formation of carbonitride, nitriding while reducing and carbonizing in a vacuum or hydrogen atmosphere at 1000 to 1300 ° C. for 3 hours or less, minimizing the amount of oxygen and maintaining appropriate amounts of carbon and nitrogen prevents the formation of pores. It is certain to improve the mechanical properties of the cermet.

The amount of oxygen is an important parameter in the preparation of carbide or carbonitride nanopowders in the above process. In general, increasing the amount of oxygen leads to the formation of pores, so it is necessary to minimize the amount of oxygen and to titrate the amount of carbon.

When the mixed pulverized powder is reduced, carbonized and simultaneously nitridated in a vacuum or hydrogen atmosphere at 1000 to 1300 ° C. for 3 hours or less, the amount of oxygen even in the case of nano powder is normal micron size, as in the example of Ti (CN) of nano grains. Is similar to the amount of oxygen in the powders.

Under the above treatment conditions, the amount of nitrogen can be freely selected depending on the process temperature, the nitrogen partial pressure during powder synthesis, and the amount of carbon added in the powder, and as a particularly stable composition, C / N (molar ratio) is 3/7, 5/5, 7/3 are preferable, and 7/3 is more preferable.

Next, in order to ensure that the cermet based on TiC or Ti (CN) has a completely solid solution phase, the cermet powder prepared by the above method is sintered under a sintering temperature and time in a vacuum atmosphere.

Full solid solution powder having no core structure in the form of (Ti, M1, M2..C) and (Ti, M1, M2 ..) (CN) having a desired composition according to the method of the present invention, a powder for cermet comprising the same, and It is possible to provide ceramics and cermet using the solid solution powder and cermet powder.

In the TiC-based or Ti (CN) -based solid solution powder, the crystal grains exhibiting the characteristics of the substantial powder can be made nanocrystalline grains of 100 nm or less, and in the powder for TiC-based or Ti (CN) cermets, 100 nm or less Aggregates exhibiting nano grains of can be provided. The present invention provides a complete solid solution as grains of the above size.

The size of the aggregates is variously adjustable. By controlling milling conditions such as time, speed and temperature, and powder synthesis conditions such as time and temperature, the size of the powder can be controlled, and in the aggregate, nano size, submicron size (more than 100 nm, less than 1 μm) All can be manufactured for micron size (a few micrometers).

However, since the manufacturing equipment and process of conventional cermets are optimized for powders of submicron size or more, when preparing aggregates of 200 nm or less, they are suitable for ease of application and economical efficiency of the present invention.

On the other hand, in the case of the solid solution metal in the solid solution powder according to the present invention, it is possible to form a completely solid solution in the solid solution range of the metal.

That is, in the fully solid solution powder of the present invention, for example, when WC is solvated, the solid solution amount can be all about the range of 15 wt.%, 30 wt.%, 60 wt.%, And more. In the case of other Mo ₂ C, NbC-added carbides, etc., it is possible to form a complete solid solution in each possible range of employment.

In the present invention, the production of high hardness cermet having high toughness is possible in two methods for sintering powder for cermet.

One method is to form a high hardness layer on the surface of the cermet and the other method is to form a high hardness coating layer on the surface of the cermet.

In order to form a high hardness layer on the former cermet surface, according to the present invention, nitrogen in the furnace is injected during sintering of the cermet powder to control the injection time and the amount of nitrogen.

That is, according to the present invention, during the sintering of the cermet powder, nitrogen of 1 to 100 torr pressure is injected into the furnace before and after the sintering temperature and the pressure is maintained during the cooling process. Eventually, the solid solution phase formed from (Ti, W, M1, M2 ..) C / (Ti, W, M1, M2 ..) (CN) is decomposed to form TiC, Ti (CN), (Ti, w, m ₁ , m ₂ ..) C or (Ti, w, m ₁ , m ₂ ..) (CN) and WC, M1C, M2C are present or absent. As a result, a high hardness phase is formed only on the surface of the cermet, so that the entire sintered cermet has high toughness and high toughness on the surface.

In addition, during the sintering process of the cermet powder according to the present invention in order to form a high hardness coating layer on the surface of the cermet, by using an atmosphere such as vacuum, argon or nitrogen, the solid solution size is further increased on the surface of the cermet, or After further increasing the bonding phase near the surface, a hard coating layer such as TiC, TiN, Ti (CN), TiAlN, TiAlCrN, or the like is formed on the surface of the cermet using CVD or PVD.

In addition, regardless of the use of the above method according to the present invention, high toughness and high hardness cermet having ultrafine or nano-sized crystal grains as a whole can be produced by the following two methods.

One method is to prepare TiC-Me or Ti (CN) -Me powders having nanocrystals according to the present invention by WC-Me, Mo ₂ C-Me, TaC-Me, NbC-Me, ZrC-Me and HfC-Me ( Me is WC-Me, Mo ₂ C-Me, TaC-Me, NbC-Me, ZrC- with powders of one or two or more binding phases selected from the group consisting of Ni, Co and Fe) and all with nanocrystal grains of 100 nm or less Fine TiC or Ti (CN) cores by mixing and sintering one or more selected from the group consisting of Ni and HfC-Ni (Me is one or two or more bonding phases selected from the group consisting of Ni, Co and Fe) according to a desired composition It is to manufacture a sintered body having a.

Another method is for cermets of TiC-Me or Ti (CN) -Me (with one or more binding phases selected from the group consisting of Ni, Co and Fe) powders with nanocrystals and the complete solid solution according to the invention. The powders are mixed according to the desired composition and then sintered to enhance the hardness of the cermet.

Hereinafter, the present invention will be described in more detail with reference to Examples.

[Example 1]

For example, TiO ₂ (anatase) having a purity of 99%, NiO having a purity of 99% having an average particle size of 45 μm, and WO ₃ having an average particle size of 20 μm were used.

They were mixed with carbon powder to choose the following five target compositions.

Namely, the target composition is (i) (Ti, W) C-Ni (containing 15 wt.% WC), (ii) (Ti, W) C-Ni (containing 30 wt.% WC), (iii) ( Ti, W) (CN) -Ni (with 15 wt.% WC, C / N = 2: 1), (iv) (Ti, W) (CN) -Ni (with 30 wt.% WC, C / N = 3: 1), (v) (Ti, W) C (containing 15 wt.% WC).

They were all high-energy ball milling using a planetary mill (Fritsch Pulverisette 7), the diameter of the WC material used was 5mm. The mass ratio of the grinding balls to the grinding powder is 20: 1.

If the material of the vessel used for the grinding process is WC, the grinding was performed for 20 hours at a speed of 250 rpm.

1 is an XRD image analysis result of the nano-powder prepared according to an embodiment of the present invention.

In FIG. 1 (a), a complete solid solution powder of (Ti, W) C (containing 15 wt.% WC) was prepared from a mixture of TiO ₂ , WO ₃ , C. In FIG. 1 (b), TiO ₂ , WO _A powder for cermets having a completely solid phase of (Ti, W) C-Ni (containing 30 wt.% WC) was prepared from a mixture of ₃ , NiO, C, and (c) in FIG. 1 shows TiO ₂ , WO ₃ It is shown that a powder for cermet with (Ti, W) (C, N) -Ni (containing 30 wt.% WC) full solid phase was prepared from a mixture of NiO, C.

As can be seen from (a) of FIG. 1, the solid solution phase formed is a single phase, and such a single phase cannot be formed conventionally. (B) and (c) of FIG. 1 also show that the Ni powder is present in a mixed form with a single solid solution phase.

By using NiO and oxides for the production of carbides or carbonitrides, it can be seen that a uniform microstructure can be obtained, and accordingly, it can be directly sintered without additional mixing in the manufacturing process of the cermet. do.

Figure 2a is a photograph of a scanning electron microscope (SEM) of (Ti, W) C-Ni (containing 15 wt.% WC) powder prepared according to an embodiment of the present invention, Figure 2b is an embodiment of the present invention Transmission electron microscopy (TEM) photograph of (Ti, W) C-Ni (containing 15 wt.% WC) powder prepared according to FIG.

It can be seen from the scanning micrograph of FIG. 2A that the powder forms a uniform aggregate of about 200 nm at a given scale, and the transmission electron micrograph of FIG. 2B also shows that the powder forms a mixed aggregate smaller than about 100 nm at a given scale. It can be confirmed.

Such aggregates are generally found in nanopowders. Except for excessive aggregation, aggregate formation helps sintering.

Table 1 shows the results of CNO element analysis of the powder prepared by the above process based on the composition. As comparative data, the same analysis was carried out for commercial powders of the same composition.

Furtherance C N O 15 wt.% WC Nano (Ti, W) C-Ni * 12.14 0.52 1.14 Commercial TiC-WC-Ni 14.19 0.00 0.99 30 wt.% WC Nano (Ti, W) C-Ni ** 10.65 0.38 1.08 Commercial TiC-WC-Ni 12.15 0.00 0.83 15 wt.% WC Nano (Ti, W) C-Ni * 11.45 5.58 0.38 Commercial TiC-WC-Ni 10.10 4.44 0.81 30 wt.% WC Nano (Ti, W) C-Ni ** 10.39 3.66 0.08 Commercial TiC-WC-Ni 9.00 3.39 0.83

The composition of * was prepared using Ti (CN) -15 wt.% WC-Ni as a starting composition.

The composition of ** was prepared using Ti (CN) -30 wt.% WC-Ni as a starting composition.

As can be seen from Table 1, the prepared nanopowders are powders for (Ti, W) C-Ni and (Ti, W) (CN) -Ni cermet having 15, 30 wt.%, In particular (Ti, W In the case of (CN) -Ni, it can be seen that it has a low oxygen content when compared with a commercial powder.

Thus, the powder produced by the above-mentioned production method having the composition of (i) to (iv) was sintered for 1 hour at a vacuum of 10 ⁻² Torr and 1510 ° C. which is a general sintering temperature.

Figure 3a is a photograph showing the microstructure of the sintered specimens in the case of the composition of (i) and (ii), the left photo shows the case of composition (i), the right photo is composition (ii) The case is shown.

Figure 3b is a photograph showing the microstructure of the sintered specimens in the case of the composition of (iii) and (iv), the left photo shows the case of composition (iii), the right photo is the composition (iv) The case is shown.

As can be seen in Figure 3a, when sintered using (Ti, W) C-Ni cermet powder showed a grain size smaller than 100nm, as can be seen in Figure 3b, (Ti, W) (CN) -Ni In the case of the cermet powder, a microstructure having a size smaller than 1 μm was shown.

As a result, conventional Ti (CN) -M1C-M2C-... Contrary to that seen in commercial systems such as -Ni / Co, it was possible to confirm a completely solid solution structure in which no core structure was observed.

Table 2 shows the mechanical properties of the cermet prepared according to an embodiment of the present invention. For comparison, the same evaluation was performed on cermets made from commercially available powders of the same size in microns.

Sintering Condition Furtherance Molding density Sintered Density Mechanical properties Porosity (g / cm ³ ) (%) (g / cm ³ ) (%) H _V (GPa) K _1C (MPam ^1/2 ) 1510 ℃ 1 hour (Ti, W) C-Ni 15 wt.% WC 3.97 63.6 6.13 100 12.3 13.2 A2B1 30 wt.% WC 4.55 63.9 7.05 100 11.1 13.8 A2B2 (Ti, W) (CN) -Ni 15 wt.% WC 3.58 57.3 6.16 98.8 12.2 12.8 A3B1 30 wt.% WC 4.48 62.8 7.03 98.5 11.2 12.6 A2B3 1400 ℃ 1 hour (Ti, W) C-Ni 15 wt.% WC 3.97 63.6 6.23 100 12.3 10.9 A1B2 30 wt.% WC 4.55 63.8 7.08 100 11.2 11.7 A1B2 (Ti, W) (CN) -Ni 15 wt.% WC 3.60 57.7 6.22 99.7 12.6 8.4 A2B1 30 wt.% WC 4.49 62.9 7.01 98.1 11.5 11.5 A2B2

As can be seen in Table 2, the prepared cermet showed a high sintered density and low porosity despite the simple composition. Moreover, the K _1C value showed 6-8 MPam ^1/2 in the general cermet of the comparative example, while the toughness value of 11-14 MPam ^1/2 was shown in the cermet according to the present invention. Therefore, unlike the related art, it is expected that the utilization of the cermet can be greatly expanded.

[Example 2]

As an example, a simple object composition was selected and eventually TiO ₂ , WO ₃ , NiO oxides having grain sizes of 100 nm or less were prepared according to the respective amounts.

As the target composition, two were selected: (i) (Ti, W) C-Ni (containing 15wt% of WC) and (ii) (Ti, W) C-Ni (containing 30wt% of WC).

After mixing and grinding the carbon powder and the nano oxide, the powder was subjected to reduction carbonization through vacuum or hydrogen, CH ₄ , CO / CO ₂ atmosphere at 1300 ° C. heat treatment.

While sintering the prepared powder for cermet, nitrogen of 1-100 torr pressure was injected into the furnace at the sintering temperature and the pressure was maintained until the end of cooling.

FIG. 4A is a FE-SEM photograph of a sintered powder for (Ti, W) C-Ni cermet containing 15 wt% of WC in a nitrogen atmosphere at 1510 ° C. for 1 hour.

As shown in FIG. 4A, two types of (Ti, W) C-Ni completely solid solutions are formed on the surface and the inside. (Ti, W) C-Ni sintered body containing 15 wt% of WC is cooled by sintering process of TiO ₂ , WO ₃ , mixed powder of NiO and C in nitrogen atmosphere (~ 100 torr) (1 hour at 1510 ℃) Sintered body manufactured through the process.

The component analysis by SEM / EDS on the surface of the cermet sintered in the nitrogen atmosphere and in the solid solution phase is shown in Table 3.

inside surface Ti 89.49 92.44 W 10.51 7.56 total 100at% 100at%
As shown in Table 3, the solutes formed have different compositions. The solid solution near the surface has more Ti than the interior, which improves the hardness of the surface portion. As for the hardness of solid solution based on TiC / Ti (CN), it is known that an increase in the amount of Ti in the solid solution causes an increase in hardness. 4A shows that grain growth in solid solution occurs with an increase in the metal bonding phase of the surface portion.

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On the other hand, Figure 4b is a FE-SEM photograph of the surface of the sintered powder for (Ti, W) C-Ni cermet containing 30wt% WC in nitrogen atmosphere for 1 hour at 1200 ℃.

As shown in Fig. 4B, the surface microstructure of the sintered compact is observed to exhibit a black TiC (or Ti (CN)) hard phase.

Therefore, harder surface microstructure is demonstrated through nitrogen atmosphere during or prior to the sintering process. These nitrogen atmosphere conditions can be maintained even in the cooling process.

[Example 3]

As an example, to adopt a simple final composition, nanooxides TiO ₂ , WO ₃ , NiO having a grain size of 100 nm or less were prepared according to the respective amounts.

As the final composition, four compositions were selected as follows. (i) (Ti, W) C-Ni (containing 15wt% WC), (ii) (Ti, W) C-Ni (containing 30wt% WC), (iii) (Ti, W) (CN) -Ni ( 15 wt% WC) and (iv) (Ti, W) (CN) -Ni (containing 30 wt% WC).

The prepared carbon powder and the nano oxides are mixed and pulverized, and the pulverized nano powders are heat treated at 1300 ° C. for 2 hours, and reduced and carbonized in a vacuum, hydrogen, CH ₄ , and CO / CO ₂ atmosphere. In the case of carbonitrides, nitrogen is injected into the furnace.

In the sintering of the prepared cermet powder, it is carried out in a vacuum or argon, nitrogen atmosphere. The TiN coating layer formed on the surface of the sintered cermet uses the PVD method. Since the TiN coating layer exhibits high hardness and wear resistance, the formation of the TiN coating layer on the surface of the cermet can increase the hardness value.

FIG. 5 is an FE-SEM photograph of the surface of a TiN coating layer by PVD method after sintering (Ti, W) C-Ni cermet powder (containing 15wt% of WC) at 1510 ° C. for one hour.

As shown in FIG. 5, the coating layer was formed on the surface of the cermet and has a thickness of 1-1.5 microns.

According to the present invention, the mechanical properties of each of the sintered bodies are shown in Table 4.

Condition Furtherance inside TiN coating layer Longitude (GPa) Toughness (MPa · m ^1/2 ) Longitude (GPa) Toughness (MPa · m ^1/2 ) Nano 1510 ℃ 1h (Ti, W) C-Ni 15 WC 12.3 13.2 14.3 8.8 30 WC 11.1 13.8 14.1 8.8 (Ti, W) (CN) -Ni 15 WC 12.2 12.0 15.3 10.2 30 WC 11.2 12.6 14.8 9.3
In Table 4, the coating layer exhibits high hardness but less toughness compared to the inner phase. Therefore, it is suitable for coating tool (internal + coating layer) cutting tool of high toughness cermet surface. [Example 4]

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As an example, first, nano powders of Ti (CN) -Ni, WC-Ni and Mo ₂ C-Ni are selected as the target composition, and eventually nano-sized (TiO ₂ , NiO), (WO ₃ , NiO) and (Mo ₂₎ , NiO) oxides were prepared according to their respective compositions.

Ti (CN) -Ni (containing 20wt% of Ni, C / N = 7: 3), (ii) WC-Ni (containing 20wt% Ni) and (iii) Mo ₂ C-Ni by the method described above Three compositions were chosen (containing 20 wt% Ni).

The carbon powder was mixed and pulverized with the prepared oxide powders and subjected to reduction carbonization by heat treatment at 1300 ° C. for 2 hours in a vacuum or hydrogen, CH ₄ , CO / CO ₂ atmosphere. In the case of carbonitride, nitrogen was injected into the vacuum.

The three nanopowders prepared by the above method were prepared by (i) Ti (CN) -Ni + WC-Ni (containing 15 wt% of WC-Ni) and (ii) Ti (CN) -Ni + Mo ₂ C-Ni ( 15 wt% of Mo ₂ C-Ni) were mixed to prepare.

FIG. 6A is a FE-SEM photograph of a sintered mixture of TiC-Ni and WC-Ni at 1510 ° C. for 1 hour, and FIG. 6B is a mixed powder of Ti (CN) -Ni and Mo ₂ C-Ni according to the present invention. It is a FE-SEM photograph of what was sintered at 1510 degreeC for 1 hour.

Figures 6a and b is a sintered mixture of carbonitrides and carbides, including Ni in particular, according to this method can easily control the hardness and composition.

[Example 5]

For example, in order to prepare a composite cermet powder, Ti (CN) -Ni, (TiO ₂ , WO ₃ , NiO) and (TiO ₂ , NiO) oxides having nanocrystals of 100 nm were prepared according to respective compositions.

Target compositions include (i) (Ti, W) (CN) -Ni (containing 30 wt% WC and 20 wt% Ni) and (ii) Ti (CN) -Ni (containing 20 wt% Ni and C The ratio of / N was chosen to be 7: 3).

(Ti, W) (CN) -Ni solid solution powder and Ti (CN) -Ni powder were mixed and sintered so as to be 30wt% Ti (CN) -Ni.

7 is a FE-SEM photograph of a mixture of (Ti, W) (CN) -Ni and 30wt% Ti (CN) -Ni and sintered at 1510 ° C. for 1 hour.

As shown in FIG. 7, the strengthening of the hardness can be easily adjusted by the method of sintering the mixed powder of the solid solution powder and the Ti (CN) -Ni.

Thus, the solid solution powder which concerns on this invention, its manufacturing method, the powder for cermet containing the said solid solution powder, the manufacturing method, the ceramic sintered compact which sintered the said solid solution powder, and the cermet using the said powder for cermet are TiC or The problem of low toughness due to the high hardness of Ti (CN) cermet can be improved, and accordingly, it can be suitably used in place of conventional WC-Co for cutting tools, mold materials and the like.

According to the solid solution powder according to the present invention, a method for producing the cermet powder including the solid solution powder, the method for producing the ceramic powder and the ceramic sintered body sintered the solid solution powder, and a cermet using the cermet powder, the TiC system or By providing a completely solid phase in the fine structure of the Ti (CN) based solid solution powder, the toughness of the cermet material is substantially improved, and it has the advantage of being able to sinter directly without additional mixing process, and other overall mechanical properties As a result, the effect of providing a high hardness, high toughness cutting tool is achieved by replacing the WC-Co cemented carbide material.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications or variations without departing from the spirit and scope of the invention. Accordingly, the appended claims will cover such modifications and variations as fall within the spirit of the invention.

Claims (43)

Consisting of carbides, carbonitrides, or mixtures of two or more metals selected from the group IVa, Va, and VIa metals, including titanium, in the periodic table, having nanocrystal grains of 100 nm or less and a solid solution without a core structure; A solid solution powder, which is prepared by reducing and carbonizing or reducing, carbonizing and nitriding an oxide of a metal. (i) carbides, carbonitrides, or mixtures thereof of one or more metals selected from Group IVa, Va, and Group VIa metals of the periodic table, and (ii) one or more metals selected from Ni, Co, and Fe, An agglomerate comprising a fully solid solution having nanocrystal grains of 100 nm or less and having no core structure, wherein the powder for cermet is produced by reducing and carbonizing or reducing, carbonizing and nitriding an oxide of a metal as a raw material. (i) carbides, carbonitrides, or mixtures of two or more metals selected from titanium, from Group IVa, Va, and Group VIa metals in the periodic table, and (ii) one or more metals selected from Ni, Co, and Fe. Powder consisting of a solid solution having a nanocrystal grain of 100 nm or less and having no core structure, and produced by reducing and carbonizing or reducing, carbonizing, and nitriding an oxide of a metal as a raw material. . Ceramics which are sintered bodies of solid solution powder according to claim 1. The cermet which is a sintered body of the powder for cermet according to claim 2. A cermet which is a sintered body of the powder for cermet according to claim 3. The method of claim 5, wherein the powder for cermet is both 100 (nm) or less with Ti (CN) -Me (Me is at least one or two bonding phases selected from the group consisting of Ni, Co and Fe) having nano-crystal grains of 100 nm or less WC-Me, Mo ₂ C-Me, TaC-Me, NbC-Me, ZrC-Ni, and HfC-Ni with nano grains (Me is one or more binding phases selected from the group consisting of Ni, Co and Fe) The cermet having a Ti (CN) core as at least one mixture selected from the group consisting of. The method of claim 5, wherein the cermet powder is Ti (CN) -Me (Me is one or two or more bonded phases selected from the group consisting of Ni, Co and Fe) having nano-grains of less than 100nm and (i) Periodic Table Carbide, carbonitride, or mixtures of two or more metals, including titanium, from Group IVa, Va, and VIa metals, and (ii) up to 100 nm nanocrystals comprising one or more metals selected from Ni, Co, and Fe. A cermet characterized by being a mixture of aggregates of completely solid solution having. The TiC, Ti (CN), (Ti, M1, M2 ..) C or (Ti, M1, M2 ..) (CN) according to any one of claims 5-8. The cermet having a hard phase of. delete delete delete The method according to any one of claims 5 to 8, which is sintered under a vacuum, argon or nitrogen atmosphere, has a solid solution phase or a bonded phase with more surface portion than the inside, and is formed on the surface by CVD or PVD. A cermet further comprising a reinforcing coating layer of TiC, TiN, Ti (CN), TiAlN, TiAlCrN or (Ti, W, M1, M2) C. delete delete delete Mixing an oxide of two or more metals selected from the group IVa, Va, and VIa metals of the periodic table having a nano size, including titanium, with a carbon powder or a carbon source to form a mixed powder (S1-1); And Reducing and carbonizing the mixed powder (S2); Solid solution powder manufacturing method consisting of a completely solid solution does not have a concentric structure comprising a. 18. The method of claim 17, further comprising grinding the mixed powder in the step (S1-1). delete delete Oxides of two or more metals selected from the group IVa, Va, and VIa metals of the periodic table having a micron size, including titanium, are mixed with a carbon powder or a carbon source to form a mixed powder, and the mixed powder is ground to a nano size or Making into a mixed powder in an amorphous state (S1-2); And Reducing and carbonizing the mixed powder (S2); Solid solution powder manufacturing method consisting of a completely solid solution does not have a concentric structure comprising a. The method of claim 21, further comprising the step of nitriding the mixed powder in the step (S2). The solid solution powder according to claim 22, wherein the reduction and carbonization are performed in a vacuum or hydrogen, CH ₄ , CO / CO ₂ atmosphere, 1000 to 1300 ° C. for 3 hours or less, and then the nitriding is performed in a nitrogen atmosphere. Manufacturing method. (i) oxides of one or more metals of nano size selected from Ni, Co, and Fe, (ii) oxides of one or more metals of nano size selected from Groups IVa, Va, and VIa metals of the periodic table, and (iii) carbon powders or Mixing the carbon source to form a mixed powder (S1-3); And Reducing and carbonizing the mixed powder (S2); Powder manufacturing method for cermet consisting of a complete solid solution does not have a concentric structure comprising a. delete 25. The method for manufacturing a powder for cermet according to claim 24, further comprising the step of pulverizing the mixed powder in the step (S1-3). delete delete (i) oxides of one or more metals of micron size selected from Ni, Co and Fe, (ii) oxides of one or more metals of micron size selected from Groups IVa, Va, and VIa metals of the periodic table, and (iii) carbon powders or Mixing a carbon source to form a mixed powder, and pulverizing the mixed powder into a mixed powder of nano size or amorphous state (S1-4); And Reducing and carbonizing the mixed powder (S2); Powder manufacturing method for cermet consisting of a complete solid solution does not have a concentric structure comprising a. 30. The method for preparing cermet powder according to claim 24 or 29, wherein (ii) uses an oxide of two or more metals of nano size selected from titanium, among the metals of Groups IVa, Va, and VIa, of the periodic table. Way. 30. The method of claim 24 or 29, further comprising the step of nitriding the mixed powder in the step (S2). The cermet according to claim 31, wherein the reduction and carbonization are performed in a vacuum or hydrogen, CH ₄ , CO / CO ₂ atmosphere, 1000 to 1300 ° C. for 3 hours or less, and then the nitriding is performed in a nitrogen atmosphere. Dragon powder manufacturing method. Consisting of carbides, carbonitrides, or mixtures of two or more metals selected from the group IVa, Va, and VIa metals, including titanium, in the periodic table, having nanocrystal grains of 100 nm or less and a solid solution without a core structure; And sintering a solid solution powder prepared by reducing and carbonizing or reducing, carbonizing and nitriding an oxide of a metal.  (i) carbides, carbonitrides, or mixtures of one or more metals selected from Group IVa, Va, and Group VIa metals in the periodic table, and (ii) one or more metals selected from Ni, Co, and Fe, up to 100 nm It is agglomerates comprising a complete solid solution having a nano-crystal grains and no core structure, and manufacturing a cermet comprising sintering a powder for cermet prepared by reducing and carbonizing or reducing, carbonizing and nitriding an oxide of a metal as a raw material. Way. 35. The method of claim 34, wherein the powder for cermet is not more than 100 nm both with Ti (CN) -Me (Me is one or two or more bonding phases selected from the group consisting of Ni, Co and Fe) having nano grains of 100 nm or less WC-Me, Mo ₂ C-Me, TaC-Me, NbC-Me, ZrC-Ni, and HfC-Ni with nano grains (Me is one or more binding phases selected from the group consisting of Ni, Co and Fe) At least one mixture selected from the group consisting of. 35. The method of claim 34, wherein the powder for cermet is Ti (CN) -Me (Me is at least one or more bonded phases selected from the group consisting of Ni, Co and Fe) having nano-grains of less than 100nm and (i) Periodic Table Carbide, carbonitride, or mixtures of two or more metals, including titanium, from Group IVa, Va, and VIa metals, and (ii) up to 100 nm nanocrystals comprising one or more metals selected from Ni, Co, and Fe. It is a mixture of the aggregate of the solid solution which has, The manufacturing method of a cermet characterized by the above-mentioned. 37. A method according to any one of claims 34 to 36, wherein the amount and time of nitrogen introduced into the furnace during the sintering are controlled to provide TiC, Ti (CN), (Ti, M1, M2. .) A method for producing a cermet comprising forming a hard phase of C or (Ti, M1, M2 ..) (CN). delete delete 37. The method according to any one of claims 34 to 36, which is sintered in a vacuum, argon or nitrogen atmosphere, has a solid solution phase or a bonded phase with more surface portion than the inside thereof, and uses TiC, Forming a reinforcement coating layer of TiN, Ti (CN), TiAlN, TiAlCrN or (Ti, W, M1, M2) C further comprising the step of forming a cermet. delete delete 34. The reinforced coating layer of claim 33, which is sintered under vacuum, argon or nitrogen atmosphere, and is coated with TiC, TiN, Ti (CN), TiAlN, TiAlCrN or (Ti, W, M1, M2) C on the surface by CVD or PVD. Ceramics manufacturing method characterized in that it further comprises the step of forming.

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