A Ti(C,N)-based cermet cutting tool material, its preparation method and application

Abstract

This invention discloses a Ti(C,N)-based cermet cutting tool material, its preparation method, and its application, comprising: ① at least one of carbonitrides, nitrides, and carbides with a titanium mass fraction of more than 45%, and one of tungsten carbides with a tungsten mass fraction of more than 55%; ② weighing various raw materials according to the formula, mixing them, and then performing alcohol wet grinding, spray granulation, molding, and argon micro-pressure sintering; ③ preparing cermet cutting tools through post-processing. The cermet in this invention contains two types of hard phase particles: black-core-gray-ring structure and white-core-gray-ring structure, exhibiting typical mixed-crystal structure characteristics. Furthermore, a 2-20 μm thick Ti(C,N) fine-grained layer is formed on the matrix surface, greatly improving surface hardness. The wear resistance, high-temperature resistance, and impact resistance of the material are significantly improved, and the cutting life of the cutting tool is increased by 3-5 times.

Description

Technical Field

[0001] This invention belongs to the field of metal ceramics technology, specifically a Ti(C,N)-based metal ceramic cutting tool material, its preparation method, and its application. Background Technology

[0002] With the rapid development of modern materials technology, various new and difficult-to-machine materials are widely used in aerospace, rail transportation, energy and power fields, which also requires cutting tool materials to develop towards higher life, higher efficiency and higher precision.

[0003] Ti(C,N)-based cermets, as a novel material for hard cutting tools, possess not only the high hardness and wear resistance of the ceramic phase but also the strength and toughness of the metallic phase. Compared to traditional WC-Co cemented carbide, Ti(C,N)-based cermets exhibit superior red hardness and resistance to high-temperature oxidation, making them suitable for dry, high-speed cutting with high machining efficiency and excellent surface finish. Therefore, they are particularly well-suited for finishing / semi-finishing cast iron, steel, and high-temperature alloys.

[0004] However, Ti(C,N)-based cermets are brittle, exhibiting high hardness but insufficient toughness, often leading to chipping of cutting tools during machining, thus limiting their application range. Improving the impact toughness of cermet materials often requires increasing the content of the binder phase, but this reduces hardness, wear resistance, and tool life. For many years, researchers have been seeking methods to strengthen and toughen cermets, but breakthroughs have been rare, and most of the technical solutions proposed in patent papers are difficult to apply in actual production.

[0005] A low-pressure nitriding sintering method for preparing gradient structure TiCN-based metal ceramics is disclosed in the related technology. However, the introduction of nitrogen gas at 10 mbar to 300 mbar not only changes the equilibrium nitrogen partial pressure in the sintering furnace, but also makes the nitriding reaction process difficult to control. The matrix composition varies greatly from the outside to the inside, which can easily cause large fluctuations in the stability of the cutting tool.

[0006] The related technology also discloses a method for preparing cobalt-free titanium-based metal ceramics with fine-grained surface by combining negative pressure nitriding and negative pressure carburizing. However, the preparation process is complex and the introduction of CH4 gas at high temperature poses a significant safety hazard and does not meet the requirements for safe production.

[0007] Therefore, this invention provides a method for preparing Ti(C,N)-based cermet cutting tool material with a surface fine-grained reinforced mixed-grain structure. Through special composition design and argon micro-pressure sintering technology, the matrix can be made to have excellent wear resistance and impact resistance, and the versatility of the cutting tool is significantly improved. Summary of the Invention

[0008] The present invention provides a Ti(C,N)-based cermet cutting tool material, the purpose of which is to solve at least one of the problems in the prior art.

[0009] The present invention also provides a method for preparing the above-mentioned Ti(C,N)-based cermet cutting tool material.

[0010] This invention also provides applications of the above-mentioned Ti(C,N)-based cermet cutting tool materials.

[0011] Specifically, the first aspect of this invention provides a Ti(C,N)-based cermet cutting tool material, comprising the following raw materials by mass fraction:

[0012] The composition includes 42.2%–58.6% titanium source, 11.5%–25.5% tungsten source, and 13.3%–19.2% metal powder.

[0013] The titanium source is at least one of titanium carbonitride, titanium nitride, and titanium carbon compound;

[0014] The tungsten source is a tungsten carbide;

[0015] The metal powder is cobalt powder or nickel powder.

[0016] According to one technical solution of the tool material technical solution of the present invention, at least the following beneficial effects are achieved:

[0017] This invention combines titanium and tungsten sources. This composition design can generate two types of hard phase particles in the metal ceramic structure. One type is a black-core-gray ring structure particle with coarse Ti-rich carbonitride particles as the core, and the other type is a white-core-gray ring structure particle with fine W-rich carbide particles as the core. The former can improve the toughness of the matrix, while the latter can play a role in dispersion strengthening and toughening.

[0018] The formation mechanism of the two hard phase particles is as follows: On the one hand, as the sintering temperature increases, a large number of coarse Ti-rich carbonitride particles are not completely dissolved and are retained as nucleation particles, while the alloy components dissolved in the binder phase precipitate around them to form (Ti,W,…)(C,N) ring phases.

[0019] On the other hand, due to the high proportion of fine W-rich carbide particles, which exceeds the solubility limit in the binder phase, most of the particles do not completely dissolve and become nucleation sites, causing other alloy components to form (Ti,W,…)(C,N) ring phases around them through a dissolution-precipitation mechanism.

[0020] Furthermore, using a Co / Ni composite binder phase can further enhance the material's toughness and impact resistance.

[0021] The raw materials prepared in this invention can not only give the matrix high strength, toughness and impact resistance, but also give the matrix surface high hardness and wear resistance, and increase the cutting life of the tool by 3 to 5 times.

[0022] According to some embodiments of the present invention, the Ti(C,N)-based cermet cutting tool material includes black-core-gray-ring structured hard phase particles and white-core-gray-ring structured hard phase particles;

[0023] The black core of the black core-gray ring structured particles is a Ti-rich carbonitride.

[0024] The gray ring structure phase in the black core-gray ring structure particles is an A(C,N) solid solution.

[0025] A includes at least one of titanium and tungsten;

[0026] The equivalent particle size of the black core-gray ring structure particles is 0.6 μm to 3.0 μm;

[0027] The white core of the white-core-gray-ring structured particles is a W-rich carbide.

[0028] The gray ring structure phase in the white core-gray ring structure particles is a B(C,N) solid solution.

[0029] B includes at least one of titanium and tungsten;

[0030] The equivalent particle size of the white-core-gray-ring structured particles is 0.4 μm to 1.5 μm;

[0031] A fine-grained layer with a thickness of 2μm to 20μm is formed on the surface of the Ti(C,N) matrix;

[0032] The fine-grained hard phase particles are Ti(C,N) with an equivalent particle size of 0.3μm to 1.8μm.

[0033] According to some embodiments of the present invention, the gray ring structure phase in the black core-gray ring structure particles is a (Ti,W,Ta,Mo,W)(C,N) solid solution.

[0034] According to some embodiments of the present invention, the gray ring structure phase in the white core-gray ring structure particles is a (Ti,W,Ta,Mo,W)(C,N) solid solution.

[0035] According to some embodiments of the present invention, the raw materials for preparing the Ti(C,N)-based cermet cutting tool material further include transition metal carbides.

[0036] According to some embodiments of the present invention, the transition metal carbide includes at least one of tantalum carbide, niobium carbide, molybdenum carbide, zirconium carbide, vanadium carbide and chromium carbide.

[0037] This invention can significantly improve the high-temperature red hardness and high-temperature wear resistance of the matrix by adding appropriate amounts of carbides such as Ta, Nb, and Zr.

[0038] According to some embodiments of the present invention, the particle size of the transition metal carbide is 1.0 μm to 4.0 μm.

[0039] According to some embodiments of the present invention, the mass fraction of titanium in the titanium source is 45% or more.

[0040] According to some embodiments of the present invention, the tungsten source contains 55% or more tungsten by mass.

[0041] According to some embodiments of the present invention, the particle size of the titanium source is 1.5 μm to 3.5 μm.

[0042] According to some embodiments of the present invention, the particle size of the tungsten source is 0.5 μm to 1.5 μm.

[0043] The second aspect of this invention discloses a method for preparing the above-mentioned Ti(C,N)-based cermet cutting tool material, comprising the following steps:

[0044] S1. The raw materials are mixed to obtain a mixture;

[0045] S2. Press the mixture into a compact to obtain a pressed blank;

[0046] S3. De-esterify the pressed compact and then sinter it;

[0047] The sintering process consists of vacuum sintering, a first argon gas micro-pressure sintering, and a second argon gas micro-pressure sintering.

[0048] The temperature of the first argon micro-pressure sintering is 1460℃~1520℃;

[0049] The temperature for the second argon micro-pressure sintering is 1250℃~1350℃.

[0050] According to some embodiments of the present invention, the mixing includes ball milling, sieving, and spray granulation.

[0051] According to some embodiments of the present invention, the ball milling and mixing is carried out in a drum ball mill.

[0052] According to some embodiments of the present invention, the ball-to-material ratio of the ball milling mixture is 6:1 to 10:1.

[0053] According to some embodiments of the present invention, the rotation speed of the ball mill mixing is 30 rpm to 50 rpm.

[0054] According to some embodiments of the present invention, the ball milling mixing time is 24 to 48 hours.

[0055] According to some embodiments of the present invention, the pressure for compression molding is 200MPa to 300MPa.

[0056] According to some embodiments of the present invention, the deesterification temperature is 400°C to 600°C.

[0057] According to some embodiments of the present invention, the deesterification time is 1h to 2h.

[0058] According to some embodiments of the present invention, the temperature of the vacuum sintering is 1100℃~1200℃.

[0059] According to some embodiments of the present invention, the vacuum degree of the vacuum sintering is less than 5 Pa.

[0060] According to some embodiments of the present invention, the vacuum sintering time is 3h to 6h.

[0061] According to some embodiments of the present invention, the argon pressure of the first argon micro-pressure sintering and the second micro-pressure sintering are both independently selected from 10 mbar to 500 mbar.

[0062] According to some embodiments of the present invention, the time for the first argon micro-pressure sintering is 0.5h to 1.5h.

[0063] According to some embodiments of the present invention, the second argon micro-pressure sintering time is 1h to 8h.

[0064] According to some embodiments of the present invention, the second argon micro-pressure sintering is followed by cooling to below 800°C; the cooling rate is 25°C / min to 35°C / min.

[0065] According to some embodiments of the present invention, the argon pressure of the first argon micro-pressure sintering is 10 mbar to 500 mbar.

[0066] According to some embodiments of the present invention, the argon flow rate of the first argon micro-pressure sintering is 3L / min to 18L / min.

[0067] According to some embodiments of the present invention, the argon pressure of the second micro-pressure sintering is 10 mbar to 500 mbar.

[0068] According to some embodiments of the present invention, the argon flow rate of the first argon micro-pressure sintering is 3L / min to 18L / min.

[0069] According to some embodiments of the present invention, the preparation method of the Ti(C,N)-based cermet cutting tool material includes the following steps:

[0070] S01. Weigh the raw materials and paraffin wax according to the proportion, and then mix them by ball milling, sieving and spray granulation to obtain the mixture.

[0071] S02. Press the mixture obtained in step S01 under a pressure of 200MPa to 300MPa to obtain a pressed blank;

[0072] S03. The pressed compact obtained in step S02 is sintered in a degreasing / sintering integrated furnace. The sintering process is as follows:

[0073] First, the temperature is raised to 400℃~600℃, and the compact is subjected to hydrogen positive pressure deesterification for 1h~2h.

[0074] The degreased compact is then heated to 1100℃~1200℃. This stage is vacuum sintering with a vacuum degree of less than 5Pa and a holding time of 3h~6h.

[0075] Then the temperature is raised to 1460℃~1520℃, and this stage is argon gas micro-pressure sintering, with a holding time of 0.5h~1.5h;

[0076] Then cool down to 1250℃~1350℃. This stage is argon gas micro-pressure sintering, and the holding time is 1h~8h.

[0077] Finally, the temperature is reduced to below 800°C at a cooling rate of 25°C / min to 35°C / min, and then cooled in the furnace to obtain the Ti(C,N)-based cermet cutting tool material with a fine-grained reinforced mixed-grain structure.

[0078] Hydrogen positive pressure deesterification is carried out at 400℃~600℃ and held for 1h~2h in order to completely remove the paraffin forming agent in the compact and avoid residual carbon in the sintering body.

[0079] Vacuum sintering at 1100℃~1200℃ and holding for 3h~6h is to allow the hard phase particles to be pre-coarsened by solid-state diffusion and to make the pores inside the sintered body open, thereby inhibiting the growth and development of particles during the subsequent liquid phase sintering process.

[0080] Argon micro-pressure sintering at 1460℃~1520℃ with a holding time of 0.5h~1.5h is performed to obtain a high density of the sintered body. The partial pressure of argon can hinder the escape of nitrogen molecules, promote the diffusion of nitrogen atoms or nitrogen molecules through the opening to the surface area for enrichment, and react with Ti and C atoms to form a Ti(C,N) fine-grained layer in situ.

[0081] Argon micro-pressure sintering is carried out at 1250℃~1350℃, and the holding time is 2h~4h. This is to make the sintered body completely dense and avoid the coarsening of hard phase particles. Secondly, it is to further promote the growth and thickening of the fine Ti(C,N) grain layer on the surface.

[0082] The cooling stage involves reducing the temperature to below 800℃ at a cooling rate of 25℃ / min to 35℃ / min in order to suppress the precipitation of alloying elements and the growth of cyclic phases, so that the matrix retains its high-temperature properties.

[0083] The third aspect of this invention discloses the application of the above-mentioned Ti(C,N)-based cermet cutting tool material in the preparation of cutting tools.

[0084] This invention, through specific composition design, enables cermets to obtain two hard phase particles with different morphologies and sizes, thereby strengthening the matrix. In addition, through argon micro-pressure sintering technology, a Ti(C,N) fine-grained layer can be generated on the matrix surface, which significantly improves the surface hardness and wear resistance.

[0085] The Ti(C,N)-based cermet cutting tool material with a fine-grained and mixed-grained structure prepared by this invention can meet both continuous high-wear-resistant machining conditions and intermittent impact-resistant machining conditions, and improve the cutting life of the tool by 3 to 5 times.

[0086] This invention has no special requirements for production equipment and the process control is simple, which is conducive to industrial promotion and application. Attached Figure Description

[0087] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to the accompanying drawings.

[0088] Figure 1 This is a SEM image of the Ti(C,N)-based cermet cutting tool material with a fine-grained, mixed-crystal structure prepared in Example 1 of the present invention. Detailed Implementation

[0089] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0090] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0091] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0092] Example 1

[0093] This embodiment describes a metal-ceramic cutting tool material, composed of the following raw materials by mass fraction:

[0094] The powder consists of 57.2% titanium carbonitride powder (75.5% by mass) with a particle size of 2.5 μm; 18.5% tungsten carbide powder (98.2% by mass) with a particle size of 0.8 μm; 14.0% Co+Ni powder with a particle size of 2.0 μm; 5.6% TaC powder with a particle size of 2.5 μm; 3.6% Mo2C powder with a particle size of 3.5 μm; and 1.1% VC powder with a particle size of 1.5 μm.

[0095] The method for preparing the cermet cutting tool material in this embodiment consists of the following steps:

[0096] S1. Titanium carbide powder, tungsten carbide powder, Co+Ni powder, TaC powder, Mo2C powder, and VC powder are mixed with paraffin wax accounting for 2.5% of the total mass of the raw materials in a drum ball mill. The ball milling medium is ethanol, the ball-to-material ratio is 8:1, the ball mill speed is 35 r / min, and the ball milling time is 36 h.

[0097] After the mixture is evenly mixed, the slurry is taken out and passed through a 200-mesh sieve, and then spray-dried to obtain the mixture.

[0098] S2. Press the mixture obtained in step S1 under a pressure of 260MPa to obtain a compact of a certain size and shape.

[0099] S3. The pressed compact obtained in step S2 is sintered in a degreasing / sintering integrated furnace. The specific sintering process is as follows:

[0100] First, the compact is heated to 500℃ and subjected to hydrogen positive pressure deesterification at a heating rate of 1℃ / min, and held at that temperature for 0.5h.

[0101] Then, the temperature was raised to 1200℃ for vacuum sintering, with a vacuum degree of less than 5Pa, a heating rate of 5℃ / min, and a holding time of 4h.

[0102] Then, the temperature was raised to 1500℃ for argon micro-pressure sintering, with an argon flow rate of 8L / min, an argon pressure of 150mbar, a heating rate of 7℃ / min, and a holding time of 1h.

[0103] The temperature was then lowered to 1300℃ for argon micro-pressure sintering, with an argon flow rate of 10L / min, an argon pressure of 300mbar, a cooling rate of 10℃ / min, and a holding time of 3h.

[0104] Finally, the temperature was reduced to below 800℃ at a cooling rate of 35℃ / min, and then cooled in the furnace to obtain a Ti(C,N)-based cermet cutting tool material with a fine-grained reinforced mixed-grain structure.

[0105] The SEM image of the Ti(C,N)-based cermet tool material prepared in this embodiment is shown below. Figure 1 As shown. By Figure 1 As can be seen, the microstructure contains hard phase particles with a black core / gray ring structure and an equivalent particle size of 0.8 μm to 2.5 μm. The black core is a Ti-rich carbonitride, and the gray ring structure is a (Ti,W,Ta,Mo,W)(C,N) solid solution. It also contains hard phase particles with a white core / gray ring structure and an equivalent particle size of 0.6 μm to 1.5 μm. The white core is a W-rich carbide, and the gray ring structure is a (Ti,W,Ta,Mo,W)(C,N) solid solution. A 6 μm thick Ti(C,N) fine-grained layer with an equivalent particle size of 0.3 μm to 1.8 μm is formed on the surface of the matrix.

[0106] The mechanical properties of the material obtained in this embodiment were tested. The prepared cermet material had a hardness of HRA93.5 and a fracture toughness of 9.9 MPa·m. 1 / 2 Its flexural strength is 2480 MPa.

[0107] Comparative Example 1

[0108] The raw material ratio of the comparative product is consistent with that of Example 1. The difference in the preparation method is that a vacuum atmosphere is used in the sintering process. Argon gas is introduced at a final firing temperature of 1500℃ with 40mbar for argon micro-pressure sintering. The holding time is 1h. After cooling, the metal ceramic tool material is obtained.

[0109] The cutting performance of the materials obtained in Example 1 and Comparative Example 1 was tested. An ISO standard TNMG160408-FG cutting tool was prepared. The material being cut was 45 steel, the cutting speed was 240 m / min, the depth of cut was 0.5 mm, and the feed rate was 0.2 mm / rev. Under the same machining parameters, a comparative test was conducted with a conventional cutting tool, requiring the flank wear Vb to be less than 0.2 mm and the surface roughness Ra to be less than 3.2 μm. The test results are shown in Table 1. According to the test results, the cutting life of the tool prepared by the method of this embodiment can be increased by 3.5 times.

[0110] Table 1. Tool cutting test results in this embodiment.

[0111]

[0112] Example 2

[0113] This embodiment describes a metal-ceramic cutting tool material, composed of the following raw materials by mass fraction:

[0114] The powder consists of 48.5% titanium carbonitride powder (66.2% by mass) with a particle size of 3.2 μm; 24.2% tungsten carbide powder (85.5% by mass) with a particle size of 1.4 μm; 15.5% Co+Ni powder with a particle size of 1.3 μm; 6.1% NbC powder with a particle size of 2.0 μm; 5.0% Mo2C powder with a particle size of 1.4 μm; and 0.7% ZrC powder with a particle size of 2.2 μm.

[0115] The method for preparing the cermet cutting tool material in this embodiment consists of the following steps:

[0116] S1. Titanium carbide powder, tungsten carbide powder, Co+Ni powder, NbC powder, Mo2C powder, and ZrC powder are mixed with paraffin wax accounting for 2.5% of the total mass of the raw materials in a drum ball mill. The ball milling medium is ethanol, the ball-to-material ratio is 6:1, the ball mill speed is 50 r / min, and the ball milling time is 48 h.

[0117] After the mixture is evenly mixed, the slurry is taken out and passed through a 200-mesh sieve, and then spray-dried to obtain the mixture.

[0118] S2. Press the mixture obtained in step S1 under a pressure of 300MPa to obtain a compact of a certain size and shape.

[0119] S3. The pressed compact obtained in step S2 is sintered in a degreasing / sintering integrated furnace. The specific sintering process is as follows:

[0120] First, the compact is heated to 400℃ and subjected to hydrogen positive pressure deesterification at a heating rate of 1℃ / min, and held at that temperature for 2 hours.

[0121] Then, the temperature was raised to 1100℃ for vacuum sintering, with a vacuum degree of less than 5Pa, a heating rate of 5℃ / min, and a holding time of 6h.

[0122] Then, the temperature was raised to 1520℃ for argon micro-pressure sintering, with an argon flow rate of 3L / min, an argon pressure of 100mbar, a heating rate of 7℃ / min, and a holding time of 0.5h.

[0123] The temperature was then lowered to 1250℃ for argon micro-pressure sintering, with an argon flow rate of 12L / min, an argon pressure of 240mbar, a cooling rate of 10℃ / min, and a holding time of 6h.

[0124] Finally, the temperature was reduced to below 800℃ at a cooling rate of 30℃ / min, and then cooled in the furnace to obtain a Ti(C,N)-based cermet cutting tool material with a fine-grained reinforced mixed-grain structure.

[0125] The microstructure and mechanical properties of the cermet obtained in this embodiment were tested. The results showed that a 10 μm thick Ti(C,N) fine-grained layer was formed on the surface of the matrix, and the material hardness was HRA93.0 and the fracture toughness was 10.3 MPa·m. 1 / 2 Its flexural strength is 2643 MPa.

[0126] Example 3

[0127] This embodiment describes a metal-ceramic cutting tool material, composed of the following raw materials by mass fraction:

[0128] The powder composition is as follows: 70.5% Ti (52.6% by mass), 2.0 μm particle size; 95.6% W (14.5% by mass), 1.0 μm particle size; 18.9% Co+Ni powder (1.6 μm particle size); 3.3% TaC powder (1.9 μm particle size); 4.9% NbC powder (2.0 μm particle size); 5.2% Mo2C powder (3.0 μm particle size); and 0.6% Cr3C2 powder (1.7 μm particle size).

[0129] The method for preparing the cermet cutting tool material in this embodiment consists of the following steps:

[0130] S1. Titanium carbide powder, tungsten carbide powder, Co+Ni powder, TaC powder, NbC powder, Mo2C powder, Cr3C2 powder, and paraffin wax accounting for 2.5% of the total mass of raw materials are added to a drum ball mill for mixing. The ball milling medium is ethanol, the ball-to-material ratio is 6:1, the ball mill speed is 50 r / min, and the ball milling time is 48 h.

[0131] After the mixture is evenly mixed, the slurry is taken out and passed through a 200-mesh sieve, and then spray-dried to obtain the mixture.

[0132] S2. Press the mixture obtained in step S1 under a pressure of 220MPa to obtain a compact of a certain size and shape.

[0133] S3. The pressed compact obtained in step S2 is sintered in a degreasing / sintering integrated furnace. The specific sintering process is as follows:

[0134] First, the compact is heated to 600℃ and subjected to hydrogen positive pressure deesterification at a heating rate of 1℃ / min, and held at that temperature for 1h.

[0135] Then, the temperature was raised to 1160℃ for vacuum sintering, with a vacuum degree of less than 5Pa, a heating rate of 5℃ / min, and a holding time of 5h.

[0136] Then, the temperature was raised to 1460℃ for argon micro-pressure sintering, with an argon flow rate of 14L / min, an argon pressure of 350mbar, a heating rate of 7℃ / min, and a holding time of 1.5h.

[0137] The temperature was then lowered to 1350℃ for argon micro-pressure sintering, with an argon flow rate of 4L / min, an argon pressure of 100mbar, a cooling rate of 10℃ / min, and a holding time of 8h.

[0138] Finally, the temperature was reduced to below 800℃ at a cooling rate of 25℃ / min, and then cooled in the furnace to obtain a Ti(C,N)-based cermet cutting tool material with a fine-grained reinforced mixed-grain structure.

[0139] The microstructure and mechanical properties of the cermet obtained in this embodiment were tested. The results showed that a 16 μm thick Ti(C,N) fine-grained layer was formed on the surface of the matrix, and the material hardness was HRA93.8 and the fracture toughness was 9.2 MPa·m. 1 / 2 Its flexural strength is 2288 MPa.

[0140] In summary, this invention uses a combination of coarse Ti-containing carbonitride or nitride powder and fine W-containing carbide powder. The advantage of this composition design is that it can generate two types of hard phase particles in the metal ceramic structure: one is a black-core-gray ring structure particle with coarse Ti-rich carbonitride particles as the core, and the other is a white-core-gray ring structure particle with fine W-rich carbide particles as the core. The former can give the matrix high toughness, while the latter can play a role in dispersion strengthening and toughening. The formation mechanisms of the two hard phase particles are as follows: On the one hand, with the increase of sintering temperature, a large number of coarse Ti-rich carbonitride particles are not completely dissolved and are retained as nucleation sites, while alloy components dissolved in the binder phase precipitate around them to form (Ti,W,…)(C,N) ring phases; on the other hand, due to the high proportion of fine W-rich carbide particles, which exceeds the solubility limit in the binder phase, most particles are not completely dissolved and become nucleation sites, causing other alloy components to also form (Ti,W,…)(C,N) ring phases around them through a dissolution-precipitation mechanism. Furthermore, adding appropriate amounts of Ta, Nb, Zr, etc., can significantly improve the high-temperature red hardness and high-temperature wear resistance of the matrix, while using a Co / Ni composite binder phase can further enhance the toughness and impact resistance of the material.

[0141] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A Ti(C,N)-based cermet cutting tool material, characterized in that, The raw materials include the following mass fractions: Titanium source 42.2%~58.6%, tungsten source 11.5%~25.5%, and metal powder 13.3%~19.2%; The titanium source is at least one of titanium carbonitride, titanium nitride, and titanium carbon compound; The tungsten source is a tungsten carbide; The metal powder is cobalt powder or nickel powder; The metal-ceramic cutting tool material includes black-core-gray-ring structured hard phase particles and white-core-gray-ring structured hard phase particles. The black core of the black core-gray ring structured particles is a Ti-rich carbonitride. The gray ring structure phase in the black core-gray ring structure particles is an A(C,N) solid solution. A includes at least one of titanium and tungsten; The equivalent particle size of the black core-gray ring structure particles is 0.6 μm to 3.0 μm; The white core of the white-core-gray-ring structured particles is a W-rich carbide. The gray ring structure phase in the white core-gray ring structure particles is a B(C,N) solid solution. B includes at least one of titanium and tungsten; The equivalent particle size of the white-core-gray-ring structured particles is 0.4μm~1.5μm; A fine-grained layer with a thickness of 2μm to 20μm is formed on the surface of the Ti(C,N) matrix; The fine-grained layer is Ti(C,N) with an equivalent particle size of 0.3μm~1.8μm.

2. The Ti(C,N)-based cermet cutting tool material according to claim 1, characterized in that, The titanium source contains more than 45% titanium by mass.

3. The Ti(C,N)-based cermet cutting tool material according to claim 1, characterized in that, The tungsten source contains more than 55% tungsten by mass.

4. The Ti(C,N)-based cermet cutting tool material according to claim 1, characterized in that, The titanium source has a particle size of 1.5 μm to 3.5 μm.

5. The Ti(C,N)-based cermet cutting tool material according to claim 1, characterized in that, The particle size of the tungsten source is 0.5μm~1.5μm.

6. A method for preparing a Ti(C,N)-based cermet cutting tool material as described in any one of claims 1 to 5, characterized in that, Includes the following steps: S1. The raw materials are mixed to obtain a mixture; S2. Press the mixture into a compact to obtain a pressed blank; S3. De-esterify the pressed compact and then sinter it; The sintering process consists of vacuum sintering, a first argon gas micro-pressure sintering, and a second argon gas micro-pressure sintering. The temperature of the first argon micro-pressure sintering is 1460℃~1520℃; The temperature for the second argon micro-pressure sintering is 1250℃~1350℃.

7. The method according to claim 6, characterized in that, The vacuum sintering temperature is 1100℃~1200℃.

8. The method according to claim 6, characterized in that, The argon pressure for both the first and second argon micro-pressure sintering is independently selected from 10 mbar to 500 mbar.

9. The application of a Ti(C,N)-based cermet material as described in any one of claims 1 to 5 in the preparation of cutting tools.

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