阅读说明：本技术 一种TiCN基微粒金属陶瓷刀具及其制备方法 (TiCN-based particle metal ceramic cutter and preparation method thereof ) 是由 西昌川範 钟海彬 于 2020-06-16 设计创作，主要内容包括：本发明公开了一种TiCN基微粒金属陶瓷刀具及其制备方法,该金属陶瓷刀具由TiCN基微粒金属陶瓷烧结体经机械加工后制备而得,所述TiCN基微粒金属陶瓷烧结体的组分组成按质量百分比计包括：TiCN40～60％、ZrC0.1～2.0％、WC15～25％、TaC和/或NbC5～15％、Co和/或Ni10～25％。该制备方法以TiO<Sub>2</Sub>为原料制备TiMCN粉末,再以TiMCN粉末、ZrC粉末、WC粉末、Ta粉末、Nb粉末、Co粉末、Ni粉末为原料,经球磨混合、压制成型/烧结处理、机械加工制备获得TiCN基微粒金属陶瓷刀具。本发明制备的刀具具有优异的耐热裂纹性,可抑制碎裂、缺损等异常损伤的发生,并在长期使用中具有耐热变形性,在碳钢、合金钢等切削和切断加工中,具有出色的切削切断性能。(The invention discloses a TiCN-based particle metal ceramic cutting tool and a preparation method thereof, wherein the metal ceramic cutting tool is prepared by machining a TiCN-based particle metal ceramic sintered body, and the TiCN-based particle metal ceramic sintered body comprises the following components in percentage by mass: 78-60% of TiCN40, 0.1-2.0% of ZrC0, 15-25% of WC, 26-15% of TaC and/or NbC5 and 25-25% of Co and/or Ni 10. The preparation method uses TiO 2 Preparing TiMCN powder as raw material, ball-milling and mixing TiMCN powder, ZrC powder, WC powder, Ta powder, Nb powder, Co powder and Ni powder as raw material, and press-forming/sinteringAnd (4) processing and machining to obtain the TiCN-based particle metal ceramic cutter. The cutting tool prepared by the invention has excellent thermal crack resistance, can inhibit the occurrence of abnormal damage such as fracture, defect and the like, has thermal deformation resistance in long-term use, and has excellent cutting performance in cutting and cutting processing of carbon steel, alloy steel and the like.)

1. A TiCN-based particle cermet tool characterized by: the metal ceramic cutting tool is prepared by machining a TiCN-based micro-particle metal ceramic sintered body, and the TiCN-based micro-particle metal ceramic sintered body comprises the following components in percentage by mass: 78-60% of TiCN40, 0.1-2.0% of ZrC0, 15-25% of WC, 26-15% of TaC and/or NbC5 and 25-25% of Co and/or Ni 10.

2. The TiCN-based particulate cermet tool of claim 1, wherein: the composition phase of the TiCN-based fine-particle cermet sintered body comprises a1 st hard phase, a 2 nd hard phase and a binding phase, wherein the 1 st hard phase has a nuclear structure.

3. The TiCN-based particulate cermet tool of claim 1, wherein: the 1 st hard phase core is mainly composed of one or two kinds of composite carbonitride of Ti, Zr, Ta and/or Nb, and the peripheral part covering the core is composed of one or two kinds of composite carbonitride of Ti, Zr, W, Ta and/or Nb.

4. The TiCN-based particulate cermet tool of claim 3, further comprising: the number ratio of the 1 st hard phase in which the tungsten-rich phase is present in the core portion of the 1 st hard phase is 5 to 10% or less.

5. The TiCN-based particulate cermet tool of claim 1, wherein: the 2 nd hard phase is composed of one or two composite carbonitrides of Ti, Zr, W, Ta and/or Nb.

6. The TiCN-based particulate cermet tool of any of claims 1-5 further including: the binder phase is mainly composed of one or two of Co and Ni.

7. A method of making a TiCN-based particulate cermet tool as claimed in any one of claims 1 to 6, characterized in that: the method comprises the following steps:

(1) preparing TiMCN powder: the component of TiO according to the weight percentage₂60-75% of powder, 0.1-2.0% of ZrC powder and 5.0-10.0% of Ta powder and/or Nb powder are used as raw materials, and TiMCN powder with the average grain diameter of 0.5-2.0 mu M is prepared without a grinding process, wherein M is at least one of Zr, Ta and/or Nb;

(2) preparing raw material powder: performing ball milling mixing on the TiMCN powder prepared in the step (1), ZrC powder, WC powder, TaC powder, Co powder and Ni powder, and performing mixture proportioning according to the following components in percentage by weight: TiCN 40-60%, ZrC0.1-2.0%, WC 15-25%, TaC and/or NbC 5-15%, Co and/or Ni 10-25%, and mixing the raw materials uniformly to obtain raw material powder;

(3) and (3) pressing and forming: compression molding the raw material powder prepared in the step (2) to obtain a pressed blank;

(4) pretreatment: heating the pressed blank prepared in the step (3) to 1300 ℃ at the speed of 0.5-13 ℃/min in the vacuum atmosphere of below 10 Pa;

(5) and (3) high-temperature sintering: heating from 1300 ℃ to 1500-1600 ℃ at the speed of 2-15 ℃/min in the nitrogen atmosphere of 500-1500Pa, and preserving the heat for 30-60 min; and cooling to 600-900 ℃ along with the furnace in a vacuum atmosphere, and then cooling to room temperature in a nitrogen atmosphere at 1000-100000Pa to obtain the TiCN-based micro-particle metal ceramic sintered body, wherein the TiCN-based micro-particle metal ceramic sintered body is machined to prepare a specified shape, so that the TiCN-based micro-particle metal ceramic cutting tool is obtained.

8. The method of making a TiCN-based particulate cermet tool of claim 7 wherein: in the step (2), the TiMCN powder, the ZrC powder, the WC powder, the TaC powder and/or the NbC powder, the Co powder and the Ni powder prepared in the step (1) are put into a rolling ball mill or a stirring ball mill, hard alloy balls are used as a grinding and mixing medium, the rotation speed of the ball mill or the stirrer is adjusted to a low speed, and the raw materials are ground and mixed in a state of a small grinding force until the raw materials are uniformly mixed to obtain raw material powder.

9. The method of making a TiCN-based particulate cermet tool according to any one of claims 7 or 8, characterized in that: in the step (3), the raw material powder is pressed and molded under a pressure of 50 to 80MPa to prepare a green compact having a predetermined shape.

Technical Field

The invention belongs to the technical field of hard alloy cutters, and particularly relates to a TiCN-based particle metal ceramic cutter and a preparation method thereof.

Background

The cutting tool is mainly made of high-speed steel, WC-based hard alloy, TiCN-based cermet, cBN and the like. Wherein, TiCN base cermet is a ceramic cutting tool material developed on the basis of TiC base cermet, compared with the traditional WC-Co hard alloy, the TiCN base cermet has higher wear resistance, heat resistance, crater wear resistance and high-temperature strength, and simultaneously, the toughness of the TiCN base cermet is higher than that of the traditional A1₂O₃The base ceramic cutter has good material. The appearance of the metal ceramic overcomes the defect of insufficient hardness of the hard alloy cutter, obtains high toughness which is difficult to achieve by the traditional ceramic cutter, and further fills the gap between the metal ceramic and the hard alloy cutter. In the aspect of cutting processing, the TiCN-based cermet has a lower friction coefficient with metal, and the surface quality of a workpiece processed under high-speed cutting is better than that of a common cutter, so that the TiCN-based cermet is more suitable for the fields of finish machining such as precision boring, precision hole processing, turning and grinding.

In recent years, in the field of cutting and cutting, there have been increasing demands for labor saving, energy saving, high speed, high efficiency, and low cost, and the performance of a cutting and cutting device has been remarkably improved. On the other hand, the use conditions of the cutting tool are more and more demanding, and the service life of the TiCN-based cermet cutting tool needs to be prolonged while the performance of the TiCN-based cermet itself needs to be improved.

Compared with WC-based hard alloy, TiCN-based metal ceramic has insufficient hardness and toughness. In order to achieve a long life of TiCN-based cermet tools, it is necessary to further improve chipping resistance, and wear resistance. However, when a cutting tool having a complicated shape is produced from a TiCN-based cermet, the TiCN-based cermet has insufficient formability and sinterability as compared with a WC-based cemented carbide, and a complicated-shaped portion of a sintered body is likely to crack; therefore, the TiCN-based cermet cutting tool produced has a problem that chipping resistance and chipping resistance are insufficient and tool life is short.

Therefore, there is a demand for a TiCN-based cermet tool which is excellent in formability and sinterability and which exhibits excellent cutting performance over a long period of use without causing abnormal damage such as chipping and chipping when subjected to cutting and cutting.

Disclosure of Invention

The invention aims to provide a TiCN-based particle cermet tool and a preparation method thereof, aiming at solving the technical problems of insufficient formability and sintering property, insufficient chipping resistance and defect resistance, short tool life and the like of TiCN-based cermet in the prior art.

In order to solve the technical problems, the invention idea is as follows: the inventors found through experimental studies on the cause of chipping, and the like of TiCN-based cermet tools: the tungsten-rich phase present in the tungsten-rich phase at the core portion where the tungsten concentration is high and the peripheral portion where the tungsten concentration is low, or in the titanium carbonitride phase, is one of the main causes of the deterioration of the chipping resistance and the defect resistance. When the W component dispersed in the TiCN-based cermet in the hard phase segregates in the sintered structure, the thermal conductivity of the hard phase is lowered, and the thermal expansion coefficient of the hard phase is not uniform, so that thermal cracking is likely to occur in the hard phase. The load generated during the cutting and cutting process further causes extension of the thermal crack to expand, and chipping or chipping occurs. Specifically, the conventional preparation method of TiCN-based cermet comprises the following steps: a TiCN-based cermet is obtained by mixing a TiCCN powder for forming a carbonitride phase (the "TiCCN powder" herein means a carbonitride powder of a Ti component and an M component, the M component may be Zr, Ta and/or Nb), at least one of a Co powder or a Ni powder for forming a binder phase, and another carbonitride phase-forming powder such as a WC powder to prepare a raw material powder, pulverizing and mixing the raw material powder, press-molding the mixture to prepare a compact, and sintering the compact. As a starting material of the TiMCN powder, sponge Ti is generally used, but the TiMCN powder production process includes a pulverization step, and the inside of the TiMCN powder for forming a hard phase is rearranged by pulverization. In addition, when the raw material powder is pulverized and mixed, a roll mill and a stirred ball mill using a cemented carbide ball medium are generally used, and in this step, the use of cemented carbide balls having large pulverization energy causes rearrangement of the TiMCN powder for forming a hard phase. As described above, when a TiCN-based cermet is produced using a large amount of the rearrangement TiMCN powder for forming a hard phase, rearrangement in the TiMCN powder occurs in the sintering step W, and a tungsten-rich phase segregates in the TiMCN hard phase, so that thermal cracking is likely to occur due to non-uniformity in the thermal expansion coefficient of the TiMCN hard phase while the thermal conductivity of the TiMCN hard phase becomes non-uniform.

In order to suppress the occurrence of thermal cracks and improve the abnormal damage resistance, the inventors considered that it is effective to form the structure of a TiCN-based cermet into a crystal structure having a uniform TiCN hard phase free from segregation of W component in the hard phase. The inventors investigated a method of preventing the tungsten-rich phase from generating a segregated TiMCN hard phase inside it or reducing the amount of generation even if it is generated. In the manufacture of TiCN-based particulate cermets, TiO is used₂(titanium dioxide) as a starting material for the TiMCN powder, the amount of the TiMCN hard phase in which the tungsten-rich phase segregates inside the TiCN-based fine-particle cermet obtained by continuously pulverizing and mixing cemented carbide pellets in the step of pulverizing and mixing the starting material powder can be significantly reduced. Further, it was found that TiCN-based cermet produced by this method is excellent in both formability and sinterability and also excellent in thermal crack resistance. That is, the TiCN-based fine particle cermet tool manufactured according to the above-described concept does not cause cracks even when a TiCN-based fine particle cermet having a complicated shape is manufactured, and does not cause abnormal damage such as chipping and chipping due to thermal cracking in cutting carbon steel or alloy steel, and exhibits excellent wear resistance over a long period of use.

Based on the above invention thought, the invention provides a TiCN-based particle cermet tool, which is prepared by machining a TiCN-based particle cermet sintered body, wherein the TiCN-based particle cermet sintered body comprises the following components in percentage by mass: 78-60% of TiCN40, 0.1-2.0% of ZrC0, 15-25% of WC, 26-15% of TaC and/or NbC5 and 25-25% of Co and/or Ni 10.

In the above-mentioned TiCN-based fine-grained cermet cutting tool, both Zr and Ti are carbides and form carbonitride, or are hard phase-forming components forming composite carbonitride of Ti, Zr, Ta, Nb and W. ZrC is used for improving the wear resistance of the cermet tool, but the content of ZrC (the content of Zr converted into carbide) is less than 0.1% (mass percentage, the same applies hereinafter), and the effect is small; on the other hand, a content of more than 2.0% may inhibit sinterability, resulting in porosity and a decrease in strength. Therefore, the average composition of ZrC is 0.1 to 2.0%.

In the above-mentioned TiCN-based fine-particle cermet cutting tool, if the WC content in the TiCN-based fine-particle cermet sintered body is less than 15%, the W content dissolved in the binder phase is insufficient, and the desired high-temperature hardness cannot be maintained, whereas if the WC content exceeds 25%, the W content in the binder phase is too high, and the high-temperature strength of the binder phase itself is rapidly reduced, so that chipping and chipping are likely to occur, and therefore the average WC composition of the cermet cutting tool is 15 to 25% by mass.

In the above-described TiCN-based fine-particle cermet cutting tool, TaC and NbC are also dissolved in the binder phase during sintering, and precipitate to form a hard phase during cooling, similarly to WC, and have an effect of improving the high-temperature strength of the hard phase. However, when the total content of one or both of TaC and NbC is less than 5%, the above-mentioned improvement effect cannot be achieved, whereas when the content exceeds 15%, the content in the hard phase becomes too high, resulting in a decrease in hardness; therefore, the total content of either or both of TaC and NbC is 5 to 15%.

In the above-described TiCN-based fine-particle cermet cutting tool, one or both of Co and Ni constitute the main body of the binder phase, and the cermet cutting tool has desired strength and toughness. However, the total content thereof is less than 10%, and sintering property cannot be secured; on the other hand, if the total content exceeds 25 mass%, the wear is rapidly deteriorated. Therefore, the total content of one or both of Co and Ni is 10 to 25%. In addition, although the binder phase actually contains W, Ta, Nb, Zr, and Ti as solid solutions, 80% or more of the binder phase is composed of one or both of Co and Ni with respect to the total mass of the binder phase, and therefore the main component of the binder phase is composed of one or both of Co and Ni.

In the above-described TiCN-based fine-particle cermet cutting tool, the cermet sintered body in the present invention is substantially composed of TiCN in the remaining part of the composition (one or two of ZrC, WC, TaC, and/or NbC, and one or two of Co and Ni), except for impurities inevitably mixed in from the production raw material to the production process. TiCN is a main constituent of the 1 st and 2 nd hard phases generated during sintering, and has an effect of improving the hardness of the cermet tool, thereby improving wear resistance. However, if the content ratio is less than 40%, the desired hardness cannot be ensured; on the other hand, if the content exceeds 60%, the strength of the cermet cutting tool is rapidly lowered, and chipping are likely to occur during cutting. Therefore, the preferable content ratio is 40 to 60%.

In the above-mentioned technical solution of the TiCN-based fine-particle cermet cutting tool, the composition phases of the TiCN-based fine-particle cermet sintered body include a1 st hard phase, a 2 nd hard phase, and a binder phase, and the 1 st hard phase has a core structure. The core of the 1 st hard phase is mainly composed of one or two kinds of composite carbonitride of Ti, Zr, Ta and/or Nb (in the case where a tungsten-rich phase exists in the core), and the peripheral portion covering the core is composed of one or two kinds of composite carbonitride of Ti, Zr, W, Ta and/or Nb. The number ratio of the 1 st hard phase in which the tungsten-rich phase is present in the core portion of the 1 st hard phase is 5 to 10% or less. The 2 nd hard phase is composed of one or two composite carbonitrides of Ti, Zr, W, Ta and/or Nb, and may form a nucleated structure phase composed of a core portion and a peripheral portion like the 1 st hard phase, or may be a substantially homogeneous non-nucleated structure phase. The binder phase mainly contains one or two of Co and Ni, and a trace amount of Zr, W, Ta and/or Nb is partially dissolved in solid solution.

The invention also provides a preparation method of the TiCN-based particle metal ceramic cutter, which comprises the following steps:

(1) preparing TiMCN powder: the component of TiO according to the weight percentage₂60-75% of powder, 0.1-2.0% of ZrC powder, Ta powder and/or Nb powder5.0-10.0% of powder is used as a raw material, and TiMCN powder with the average grain diameter of 0.5-2.0 mu M is prepared without a grinding process, wherein M is at least one of Zr, Ta and/or Nb;

(2) preparing raw material powder: ZrC according to the following components in percentage by weight: 0.1-2.0%, WC: 15-25%, and one or two of TaC and/or NbC in total: 5-15%, and one or two of Co and Ni in total: 10 to 25% and the balance of unavoidable impurities and an average composition of TiCN; ball-milling and mixing the TiMCN powder prepared in the step (1), ZrC powder, WC powder, TaC powder and/or NbC powder, Co powder and Ni powder until all raw materials are uniformly mixed to prepare raw material powder;

(3) and (3) pressing and forming: compression molding the raw material powder prepared in the step (2) to obtain a pressed blank;

(4) pretreatment: heating the pressed blank prepared in the step (3) to 1300 ℃ at the speed of 0.5-13 ℃/min in the vacuum atmosphere of below 10 Pa;

(5) and (3) high-temperature sintering: heating from 1300 ℃ to 1500-1600 ℃ at the speed of 2-15 ℃/min in the nitrogen atmosphere of 500-1500Pa, and preserving the heat for 30-60 min; and cooling to 600-900 ℃ along with the furnace in a vacuum atmosphere, and then cooling to room temperature in a nitrogen atmosphere at 1000-100000Pa to obtain the TiCN-based micro-particle metal ceramic sintered body, wherein the TiCN-based micro-particle metal ceramic sintered body is machined to prepare a specified shape, so that the TiCN-based micro-particle metal ceramic cutting tool is obtained.

In the technical scheme of the preparation method of the TiCN-based particle metal ceramic cutter, TiO is used as the step (1)₂The TiMCN powder as a starting material can be prepared by a method conventionally known in the art, and the production method itself is not particularly limited. In the manufacture of TiCN-based particulate cermets, TiO is used₂(titanium dioxide) as a starting material for the TiMCN powder, the amount of the TiMCN hard phase in which the tungsten-rich phase segregates inside the TiCN-based fine-particle cermet obtained by continuously pulverizing and mixing cemented carbide pellets in the step of pulverizing and mixing the starting material powder can be significantly reduced. Further, the inventors have studied and found that TiCN-based cermet produced by this method is excellent in both formability and sinterabilityAnd also has excellent thermal crack resistance.

In the above-mentioned method for producing a TiCN-based fine-particle cermet cutting tool, in the step (2), it is preferable that the TiMCN powder produced in the step (1) and the ZrC powder, the WC powder, the TaC powder and/or the NbC powder, the Co powder and the Ni powder are charged into a rolling ball mill or a stirring ball mill, and the raw material powder is obtained by using a cemented carbide ball as a grinding/mixing medium, adjusting the rotation speed of the ball mill or the stirrer to a low speed, grinding and mixing the materials in a state of a small grinding force, and uniformly mixing the materials.

In the above-mentioned method for producing a TiCN-based fine-particle cermet cutting tool, in the step (3), the raw material powder is preferably press-molded under a pressure of 50 to 80MPa to prepare a green compact having a predetermined shape.

In the technical scheme of the preparation method of the TiCN-based particle metal ceramic cutting tool, the average particle size of the TiCCN powder is 0.5-2.0 mu m, so that the excessive grinding state of the TiCCN powder caused by using a hard alloy grinding medium is prevented. Further preferably, the fischer-tropsch particle size of Co is 1-4 um; the Fisher size of Ni is 1-3 um; the Fisher size of TaC is 1-3 um; the Fisher size of the ZrC is 1-4 um; the Fisher size of the WC powder is 1-10 um.

The porosity of the TiCN-based fine-particle cermet sintered body prepared by the preparation method of the TiCN-based fine-particle cermet tool meets the requirements of A04 below and B00(A type refers to the porosity size of less than 10 microns, and B type refers to the porosity of more than 10 microns and less than 25 microns) specified in the national standard GB/T3489-2015 of the people's republic of China, and coarse porosity is not formed on the cermet sintered body, so that the strength, the toughness and the thermal crack resistance of the cermet tool are improved.

The TiCN-based particle metal ceramic cutter and the preparation method thereof provided by the invention have the following beneficial effects:

(1) the cermet cutting tool of the present invention has a composition, sintered body structure and porosity within predetermined appropriate ranges, in particular, the structure of the cermet sintered body is composed of a binder phase, a1 st hard phase and a 2 nd hard phase having a core structure, and the 1 st hard phase of the nuclear structure has a core portion mainly composed of one or two composite carbonitrides of Ti, Zr, Ta and/or Nb, and a peripheral portion covering the core portion composed of one or two composite carbonitrides of Ti, Zr, W, Ta and/or Nb, and the number proportion of the 1 st hard phase with tungsten-rich phase in the core part is below 5-10%, so that the TiCN-based particle metal ceramic cutting tool of the invention is used in the processing of cutting carbon steel, alloy steel and the like, the cutting fluid does not cause abnormal damage such as cracking and defect caused by thermal cracking, and can exert good cutting performance after long-term use.

(2) The cermet sintered body of the present invention has good formability, sinterability and can improve the density of the sintered body by adjusting the content of the constituent components, so that the strength, toughness and thermal crack resistance of the cermet tool are further improved, and the TiCN-based fine-particle cermet tool of the present invention has excellent chipping resistance and long service life.

Drawings

FIG. 1 is a 7500-fold reflection electron image of a cross section of a TiCN-based fine-particle cermet sintered body prepared in example.

Detailed Description

So that the technical solutions of the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings, it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, belong to the present invention.

The TiCN-based fine-particle cermet cutting tool in the present embodiment is prepared by machining a TiCN-based fine-particle cermet sintered body, and the components of the TiCN-based fine-particle cermet sintered body include, by mass: 55.0 percent of TiCnC, 1.0 percent of ZrC, 16.0 percent of WC, 10.0 percent of TaC, 15.0 percent of Co and 3.0 percent of NiC.

The preparation method of the TiCN-based particle metal ceramic cutter specifically comprises the following steps:

(1) preparing TiMCN powder: the component of TiO according to the weight percentage₂Taking 65% of powder, 0.6% of ZrC powder and 7.0% of Ta powder and/or Nb powder as raw materials, and preparing TiMCN powder with the average particle size of 0.5-2.0 mu M without a grinding process, wherein M is at least one of Zr, Ta and/or Nb;

(2) preparing raw material powder: mixing the TiMCN powder prepared in the step (1), ZrC powder with the average particle size of 1-4um, WC powder with the average particle size of 1-10um, TaC powder with the average particle size of 1-3um, Co powder with the average particle size of 1-4um and Ni powder with the average particle size of 1-3um according to the following components in percentage by weight: TiCN 55%, ZrC 1%, WC 16%, TaC and/or NbC 10%, Co 15% and Ni 3%, loading into a rolling ball mill or an agitating ball mill, using hard alloy balls as a grinding and mixing medium, adjusting the rotating speed of the ball mill or the agitator to be low, grinding and mixing under the state of small grinding force until all raw materials are uniformly mixed to obtain raw material powder;

(3) and (3) pressing and forming: pressing and molding the raw material powder by using the pressure of 80MPa to prepare a pressed blank with a specified shape;

(4) pretreatment: heating the pressed blank prepared in the step (3) to 1300 ℃ at the speed of 13 ℃/min in the vacuum atmosphere of below 10 Pa;

(5) and (3) high-temperature sintering: heating from 1300 ℃ to 1600 ℃ at the speed of 10 ℃/min in the nitrogen atmosphere of 500Pa, and preserving the heat for 60 min; and cooling to 900 ℃ along with the furnace in a vacuum atmosphere, and then cooling to room temperature in a nitrogen atmosphere at 2000Pa to obtain a TiCN-based fine particle metal ceramic sintered body, and machining the TiCN-based fine particle metal ceramic sintered body to prepare a specified shape to obtain the TiCN-based fine particle metal ceramic cutter.

Physical property measurements were made on the TiCN-based cermet sintered body prepared in this example, as shown in Table 1:

TABLE 1 TiCN-based cermet sintered body physical Properties

Static physical Properties	Density of	Hv-30	K1c	TRS	Porosity of
						Measured value	6.95g/cc	16.0GPa	9.0MPa·m0.5	2.5GPa	A02B00

The cross section of the TiCN-based cermet sintered body prepared in this example was observed using a scanning electron microscope, and as shown in FIG. 1, it was a sintered body structure having a binder phase, a1 st hard phase and a 2 nd hard phase. The 1 st hard phase has a core structure, and the core portion thereof is mainly composed of one or two composite carbonitrides of Ti, Zr, Ta and/or Nb, and the peripheral portion covering the core portion is composed of one or two composite carbonitrides of Ti, Zr, W, Ta and/or Nb, corresponding to a dark substance in the figure. The 2 nd hard phase corresponds to a light dark substance in the figure, is composed of one or two kinds of composite carbonitrides of Ti, Zr, W, Ta and/or Nb, and is a nearly homogeneous non-nucleated structural phase. The bonding corresponds to the light-colored substance in the figure, which mainly comprises Co and Ni, and trace Zr, W, Ta and/or Nb are partially dissolved in solid solution.

It will be appreciated by those of ordinary skill in the art that the embodiments described herein are intended to assist the reader in understanding the principles of the invention and are to be construed as being without limitation to such specifically recited embodiments and examples. Those skilled in the art can make various other specific changes and combinations based on the teachings of the present invention without departing from the spirit of the invention, and these changes and combinations are within the scope of the invention.