High-toughness cermets and cutting tools

Abstract

This invention provides a highly tough cermet and a method for producing the same. [Solution] The high-toughness cermet consists of (1) mainly titanium carbides, nitrides, nitrogen carbides, or any composition thereof, and (2) carbides, nitrides, nitrogen carbides, or any composition thereof of at least one metallic element from groups IVB, VB, and VIB of the periodic table excluding titanium, and if (1) and (2) are different, a hard phase which is nitride, a bonding phase which is at least two transition metals which are cobalt, nickel, and iron, and at least two of tantalum, niobium, manganese, ruthenium, rhenium, yttrium, and cerium, and also contains at least one of tantalum, niobium, and manganese, and is distributed in a fine and uniform dispersion state in the microstructure of the cermet, wherein the hard phase contains dispersion-strengthened hard phase precipitates which precipitate when some of the metallic elements of the metal strengthener react with carbon.

Description

Technical Field

[0001] The present disclosure belongs to the field of cermet technology, and specifically relates to a high-strength and toughness cermet and a manufacturing method thereof.

Background Art

[0002] As a substitute material for upgrading the grade of cemented carbide materials, Ti(C, N)-based cermets are well-suited for continuous, dry cutting of cermet tools at high speed, high precision, and larger feed rates due to their higher wear resistance, lower friction coefficient with metals, better high-temperature performance, and oxidation resistance, significantly improving the cutting efficiency and service life. Ti(C, N)-based cermets are manufactured by combining soft transition metals (Ni, Co) with ceramic matrix phases such as TiC, TiN, Ti(C, N), and secondary carbides (e.g., Mo2C, WC, TaC, etc.) through powder metallurgy methods, and are composite materials with high hardness and high wear resistance. Since their material properties can effectively fill the gaps in the cutting of cemented carbide and oxide ceramic materials, they are widely applied in the field of high-speed precision machining to obtain excellent surface finishes. With the increasing demand for continuously improving current processing efficiency, cermets operate under high-temperature and high-speed cutting conditions, and their poor chipping resistance as ceramic characteristics becomes prominent, making sudden chipping likely to occur, reducing tool life, and affecting the surface finish of the workpiece. To obtain desirable properties such as yield strength, red hardness, resistance to plastic deformation, and wear resistance, based on scientific theories such as solid solution strengthening, dispersion strengthening, and grain boundary strengthening of materials, the cermet tools and their manufacturing methods currently used in steel material processing still have room for improvement.

Summary of the Invention

Problems to be Solved by the Invention

[0003] In order to solve the problems existing in the prior art, the main objective of the present invention is to propose a high-strength and toughness cermet and a manufacturing method thereof.

Means for Solving the Problems

[0004] (1) mainly consisting of titanium carbides, nitrides, nitrogen carbides, or any composition thereof, and (2) consisting of carbides, nitrides, nitrogen carbides, or any composition thereof of at least one metallic element from groups IVB, VB, and VIB of the periodic table other than titanium, and if (1) and (2) are different, a hard phase which is a nitride, A bonded phase consisting of at least two transition metals, cobalt, nickel, and iron, A high-toughness cermet comprising a metal reinforcing agent that is at least two of tantalum, niobium, manganese, ruthenium, rhenium, yttrium, and cerium, and also contains at least one of tantalum, niobium, and manganese, and is distributed in a fine and uniform dispersion in the microstructure of the cermet, wherein the hard phase contains dispersion-reinforced hard phase precipitates containing at least one of tantalum carbide and niobium carbide, which precipitate when some of the metal elements of the metal reinforcing agent react with carbon, and some other metal elements of the metal reinforcing agent solid-solve in the binder phase to form a solid-solution-reinforced binder phase.

[0005] Preferably, the binding phase accounts for 10-24 wt% of the total cermet weight, and the hard phase accounts for 76-90 wt% of the total cermet weight.

[0006] Preferably, the particle size of the hard phase is 0.5 to 5.0 μm, and more preferably 0.8 to 2.0 μm.

[0007] Preferably, the metal reinforcing agent comprises at least one of tantalum, niobium, and manganese, with tantalum accounting for 0.35 to 6.0 wt% of the total cermet weight, niobium for 0.2 to 2.0 wt%, and manganese for 0.3 to 4.0 wt%.

[0008] Preferably, the metal reinforcing agent comprises at least one of tantalum, niobium, and manganese, where tantalum accounts for 0.4 to 2.4 wt% of the total cermet weight, niobium accounts for 0.3 to 0.8 wt% of the total cermet weight, and manganese accounts for 0.5 to 2.0 wt% of the total cermet weight.

[0009] Preferably, the mass ratio of tantalum to niobium added to the bonding phase is (1-4):1, and more preferably 2:1.

[0010] Preferably, the proportion of manganese added to the binding phase in the metal strengthening agent is ≤50 wt%, and more preferably ≤33.3 wt%.

[0011] Preferably, in the same scanning electron microscope image, the hard phase includes a first hard phase and a second hard phase, where the first hard phase mainly appears as a phase having a black core-gray outer periphery structure and a phase having a black-gray structure, and the first hard phase mainly consists of titanium carbide, titanium nitride, and titanium nitride carbide; the second hard phase mainly appears as a phase having a light-colored core-gray outer periphery structure; the binding phase mainly exhibits a phase having a medium-luminosity structure, and numerous micro-nanometer precipitates are deposited in a point-like manner at the interface between the binding phase and the hard phase.

[0012] S1 prepares the raw materials for the metal reinforcing agent, (1) mainly consisting of titanium carbides, nitrides, nitrogen carbides, or any composition thereof, and (2) consisting of carbides, nitrides, nitrogen carbides, or any composition thereof of at least one metallic element from groups IVB, VB, and VIB of the periodic table other than titanium, and if (1) and (2) are different, a hard phase powder which is nitride and a bonding phase powder which is at least two of the transition metals cobalt, nickel, and iron are prepared, and then the hard phase powder, bonding phase powder, metal reinforcing agent raw material in step S1, solvent and molding agent are mixed, and after ball milling treatment is performed again, a mix is ​​obtained by spray preparation in S2. S3 involves press molding the mix to obtain a compacted powder body, A method for producing the cermet, comprising S4, in which a compacted molded body is placed in a sintering furnace, the temperature is raised to a molding agent removal temperature in a predetermined sintering process, the molding agent is removed, and then low-pressure atmospheric sintering is performed, during the sintering process, some of the metal fine particles of the metal reinforcing agent react with carbon, precipitating fine dispersion-reinforced hard phase precipitates dispersed in the hard phase, and some other metal fine particles of the metal reinforcing agent solid-solve in the binder phase, forming a solid-solution-reinforced binder phase, and finally a high-toughness cermet is obtained.

[0013] Preferably, in step S1, the metal reinforcing agent raw material includes metal powders, oxides, complexes, salts, or any composition thereof of at least two metal elements from among tantalum, niobium, manganese, ruthenium, rhenium, yttrium, and cerium.

[0014] Preferably, in step S1, the metal reinforcing agent raw material is mixed with a molding agent and a solvent, pulverized using a ball mill, dried, and then subjected to a hydrogen reduction treatment to obtain metal ultrafine particles as a metal reinforcing agent, with a particle size of 100 to 500 nm.

[0015] Preferably, in step S1, the hydrogen reduction temperature is 400 to 800°C.

[0016] Preferably, in steps S1 and S2, the molding agent is at least one selected from paraffin with a melting point of 48 to 56°C, and from PEG1000 to PEG20000, and the solvent is at least one selected from anhydrous ethanol and deionized water.

[0017] Preferably, in step S2, the amount of metal reinforcing agent added is 0.5 to 5 wt% of the total amount of cermet, and more preferably 1.2 to 3.6%.

[0018] Preferably, in step S4, the atmosphere inside the sintering furnace during the molding agent removal process is a hydrogen atmosphere or a vacuum atmosphere. In step S1, when the metal reinforcing agent raw material is subjected to hydrogen reduction treatment, the atmosphere inside the sintering furnace during the molding agent removal process is a vacuum atmosphere. In step S1, if the metal reinforcing agent raw material is used directly, the atmosphere inside the sintering furnace during the molding agent removal process is a hydrogen atmosphere.

[0019] Preferably, in step S4, the low-pressure atmosphere sintering is performed by first raising the temperature to A, then introducing a process gas at x mbar, and then raising the temperature to B in a nitrogen atmosphere at a heating rate of 2 to 10°C / min, after which the process is moved to vacuum sintering, held at B temperature for 0.5 to 3 hours, then cooled to 1200°C in a process gas partial pressure atmosphere of y mbar, and finally cooled under high pressure in an argon atmosphere, where A temperature is 1000 to 1400°C, B temperature is 1400 to 1600°C, x is 0.5 to 60, y is 10 to 100, and the process gas is at least one selected from nitrogen, argon, and helium.

[0020] A cutting tool comprising a substrate made of the cermet or a cermet manufactured according to the manufacturing method described above. [Effects of the Invention]

[0021] The beneficial effects of this invention are as follows:

[0022] The present invention comprises (1) mainly titanium carbides, nitrides, nitrogen carbides, or any composition thereof, and (2) carbides, nitrides, nitrogen carbides, or compositions thereof of at least one metallic element from groups IVB, VB, and VIB of the periodic table other than titanium, and if (1) and (2) are different, a hard phase which is nitride, a bonding phase which includes at least two transition metals which are cobalt, nickel, and iron, and at least two of tantalum, niobium, manganese, ruthenium, rhenium, yttrium, and cerium. This invention proposes a highly tough cermet and a method for producing the same, comprising a metal strengthening agent that further contains at least one of tantalum, niobium, and manganese, and is distributed in a fine and uniformly dispersed state in the microstructure of the cermet, wherein the hard phase contains dispersion-strengthened hard phase precipitates containing at least one of tantalum carbide and niobium carbide, which precipitate when some of the metal elements of the metal strengthening agent react with carbon, and other metal elements of the metal strengthening agent solid-solve in the binder phase to form a solid-solution-strengthened binder phase. The present invention enhances the overall performance of the cermet, such as hardness, toughness, high-temperature stability, and wear resistance, by dispersion strengthening of the hard phase and solid-solution strengthening of the binder phase.

[0023] (1) Regarding the improvement of hardness and wear resistance, at least one metal carbide, nitride, carbonitride or their combination of Group IVB, VB, and VIB of the periodic table mainly composed of titanium is introduced into the hard phase, and the dispersion-strengthened hard phase precipitates formed by the reaction of the metal strengthener and carbon are combined, so that the hardness and wear resistance of the material are significantly improved.

[0024] (2) Regarding the enhancement of toughness, at least two of the transition metals cobalt, nickel, and iron are used as the matrix in the bonding phase, and these metals have good plasticity and toughness. In addition, some metal elements of the metal strengthener are dissolved in the bonding phase to form a solid solution-strengthened bonding phase, further improving the strength and toughness of the bonding phase.

[0025] (3) Regarding the improvement of high-temperature stability, the fine and uniform dispersion distribution of the metal strengthener in the cemented carbide effectively suppresses the growth of crystal grains and phase transformation at high temperatures, enhancing the thermal stability and creep resistance of the material.

[0026] (4) Regarding the improvement of comprehensive performance, through the design of two-phase strengthening, that is, dispersion strengthening of the hard phase and solid solution strengthening of the bonding phase, the comprehensive performance of the cemented carbide such as hardness, toughness, high-temperature stability and wear resistance is improved.

Brief Description of the Drawings

[0027] [Figure 1] Figure 1 is an electron micrograph of the internal structure of the cemented carbide according to the present invention.

Embodiments for Carrying Out the Invention

[0028] The present invention proposes a high-toughness cemented carbide and its manufacturing method. With the design concept of solid solution strengthening of the bonding phase, the hardness and high-temperature performance of the material are enhanced by the dispersion precipitation and carbonization of a slightly supersaturated strengthening metal.

[0029] Ta possesses excellent high-temperature corrosion resistance, and its atomic radius is large, 15% to 18% larger than that of Ni, Co, and Fe atoms. Further addition of solid solutions of Co and Ni bonding phases increases the lattice constant, and the resistance of the formed elastic stress field to dislocation motion also increases. In addition, Ta can reduce the stacking fault energy of the γ solid solution. Studies have shown that the strong oxidizing properties of tantalum suppress shish kebab creep in the γ' phase, and alloys with added tantalum exhibit better high-temperature strength than the control group, with their creep rate reduced by nearly half. Thus, the instantaneous tensile strength and creep performance of the γ solid solution are clearly improved.

[0030] Nb is also a commonly used solid solution strengthening element. Its atomic radius is larger than that of W and Mo, and 15-18% larger than that of Ni, Co, and Fe atoms. The increase in the lattice constant of Nb is more pronounced than that of W and Mo, so the solid solution strengthening effect of Nb is greater. Nb significantly reduces the stacking fault energy of the γ matrix, thus significantly reducing the creep rate and improving creep performance. Nb is also a carbide-forming element and can act as a grain growth inhibitor, refining the microstructure, while simultaneously dispersing phases and significantly increasing the thermal hardness, thermal shock resistance, thermal pressure resistance, and oxidation resistance of alloys.

[0031] High-melting-point metal Re, with an atomic radius 10% larger than Ni and chemical properties similar to manganese and technetium, enters the bonding phase, forms solid solutions, causes lattice strain, generates an elastic stress field, inhibits dislocation motion, and increases the strength of rhenium-containing alloys.

[0032] Ru strengthens the alloy through solid solution, expanding the alloy lattice and generating a long-range stress field. Ru primarily dissolves into the γ phase, creating a large negative mismatch in the alloy, thereby extending the alloy's durability at high temperatures and low stresses.

[0033] The electron shell configuration of rare earth elements differs from that of conventional elements. By giving rare earth elements high bond energy and strong coordinating ability, filling crystal vacancies, and reducing the number of crystal defects, rare earth elements play an important role in improving the stability of the crystal structure.

[0034] Preferably, as shown in Figure 1, in the same scanning electron microscope image, the hard phase includes a first hard phase 1 and a second hard phase 2, where the first hard phase 1 mainly appears as a phase having a black core-gray outer periphery structure and a phase having a black-gray structure, and the first hard phase 1 mainly consists of titanium carbide, titanium nitride, and titanium nitride carbide; the second hard phase 2 mainly appears as a phase having a light-colored core-gray outer periphery structure; the solid solution-strengthened bonded phase 3 mainly exhibits a phase having a medium-brightness structure, and there are numerous micro-nano precipitated phases 4 deposited in a point-like manner at the interface between the solid solution-strengthened bonded phase 3 and the hard phase.

[0035] Example 1 S1 is obtained by mixing tantalum and niobium oxides in an equivalent ratio of tantalum and niobium oxides with a mass ratio of 2:1, adding PEG2000, ball milling with anhydrous alcohol for 20 hours, spray drying, and then reduction sintering in a pusher-type continuous firing furnace at 700°C in a hydrogen atmosphere to obtain ultrafine metal particles as a metal strengthening agent. The raw materials selected were a metal strengthening agent, cobalt / nickel bond phase powder, titanium-containing cubic carbonitride powder, molybdenum carbide powder, tungsten, tantalum, and niobium carbide powders, and tungsten carbide. The mass percentages of each raw material were 1.5 wt% for the metal strengthening agent, 15 wt% for the cobalt / nickel bond phase powder, 50 wt% for the titanium-containing cubic carbonitride powder, 15 wt% for the solid solution carbides of tungsten, tantalum, and niobium, and 2 wt% for the molybdenum carbide powder. S2 is obtained by ball milling a mixture of S2, where the composition is t%, the remainder being tungsten carbide, the sum of the mass percentages of each raw material is 100 wt%, the particle size of the powder is <1.8 μm, and the mixture consists of a metal reinforcing agent, a cobalt / nickel bond phase powder, a titanium-containing cubic carbonitride powder, solid solution carbides of tungsten, tantalum, and niobium, molybdenum carbide powder, tungsten carbide, and a molding agent, with paraffin (content 2.0 wt%) used as the molding agent and anhydrous ethanol as the solvent, and after ball milling, drying. S3 involves press molding the mix to obtain a compacted powder body, A method for producing a high-toughness cermet, comprising S4: heating a compacted body in a vacuum atmosphere to the temperature at which the molding agent is removed, removing the molding agent, heating the compacted body from which the molding agent has been removed to 1150°C in a vacuum atmosphere, then introducing 50 mbar nitrogen gas, heating and sintering in a nitrogen atmosphere to 1450°C at a heating rate of 6°C / min, then proceeding to vacuum sintering, holding at 1450°C for 1.5 hours, then cooling to 1200°C in a 30 mbar argon atmosphere, and finally cooling under high pressure to room temperature in an argon atmosphere to obtain a cermet.

[0036] Example 2 S1 selects tantalum and niobium oxides in equivalent amounts with a mass ratio of 2:1 for use as a metal reinforcing agent, The following raw materials were selected: tantalum and niobium oxides (calculated in equivalent amounts with a mass ratio of tantalum to niobium of 2:1), cobalt / nickel bonded phase powder, titanium-containing cubic carbonitride powder, molybdenum carbide powder, tungsten, tantalum, and niobium solid solution carbides, and tungsten carbide. The mass percentages of each raw material were as follows: the total amount of tantalum and niobium in the tantalum and niobium oxide powder (with a mass ratio of tantalum to niobium of 2:1) was 1.5 wt%, the cobalt / nickel bonded phase powder was 15 wt%, the titanium-containing cubic carbonitride powder was 50 wt%, and tungsten, tungsten, and The solid solution carbides of tantalum and niobium make up 15 wt%, the molybdenum carbide powder makes up 2 wt%, and the remainder is tungsten carbide. The total mass percentage of each raw material is 100 wt%, and the particle size of the powder is <1.8 μm. The ultrafine metal powder, cobalt / nickel bonded phase powder, titanium-containing cubic carbonitride powder, solid solution carbides of tungsten, tantalum, and niobium, molybdenum carbide powder, tungsten carbide, and molding agent are ball-milled. Paraffin (content 2.0 wt%) is used as the molding agent and anhydrous ethanol is used as the solvent. After ball-milling, the mixture is dried to obtain a mixed powder S2. S3 involves press molding the mix to obtain a compacted powder body, A method for producing a high-toughness cermet, comprising S4: heating a compacted body in a hydrogen gas atmosphere to a molding agent removal temperature of 700°C, removing the molding agent; heating the compacted body from which the molding agent has been removed to 1150°C under a vacuum atmosphere; introducing 50 mbar of nitrogen gas; then heating and sintering in a nitrogen atmosphere to 1450°C at a heating rate of 6°C / min; then proceeding to vacuum sintering; holding at 1450°C for 1.5 hours; then cooling to 1200°C in a 30 mbar argon atmosphere; and finally cooling under high pressure to room temperature in an argon atmosphere to obtain a cermet.

[0037] Example 3 S1 is obtained by mixing tantalum oxide and ammonium rhenate in an equivalent ratio of 1:1 mass ratio of tantalum to rhenium, adding PEG2000, ball milling with anhydrous alcohol for 20 hours, spray drying, and then reduction sintering in a pusher-type continuous firing furnace at 700°C in a hydrogen atmosphere to obtain ultrafine metal particles as a metal strengthening agent. The raw materials selected were a metal strengthening agent, cobalt / nickel bond phase powder, titanium-containing cubic carbonitride powder, molybdenum carbide powder, and tungsten, tantalum, and niobium carbide powders. The mass percentages of each raw material were as follows: metal strengthening agent 2 wt%, cobalt / nickel bond phase powder 15 wt%, titanium-containing cubic carbonitride powder 55 wt%, solid solution carbides of tungsten, tantalum, and niobium 10 wt%, and molybdenum carbide powder 1.8 wt%. The remainder is tungsten carbide, the sum of the mass percentages of each raw material is 100 wt%, and the particle size of the powder is <1.8 μm. A metal reinforcing agent, cobalt / nickel bond phase powder, titanium-containing cubic carbonitride powder, solid solution carbides of tungsten, tantalum, and niobium, molybdenum carbide powder, tungsten carbide, and a molding agent are ball-milled, paraffin (content 2.0 wt%) is used as the molding agent, and anhydrous ethanol is used as the solvent. After ball milling, the mixture is dried to obtain a mixed powder S2.

[0038] S3 involves press molding the mix to obtain a compacted powder body, A method for producing a high-toughness cermet, comprising S4: heating a compacted body in a vacuum atmosphere to the temperature at which the molding agent is removed, removing the molding agent, heating the compacted body from which the molding agent has been removed in a vacuum atmosphere to 1150°C, then introducing 50 mbar of nitrogen gas, heating and sintering in a nitrogen atmosphere to 1450°C at a heating rate of 6°C / min, then proceeding to vacuum sintering, holding at 1450°C for 1.5 hours, then cooling to 1200°C in a 30 mbar argon atmosphere, and finally cooling under high pressure to room temperature in an argon atmosphere to obtain a cermet.

[0039] Example 4 S1 is obtained by mixing tantalum oxide, yttrium oxide, and manganese carbonate in an equivalent ratio of tantalum, yttrium, and manganese at a mass ratio of 1:1:1, adding PEG2000, ball milling with anhydrous alcohol for 20 hours, spray drying, and then reduction sintering in a pusher-type continuous firing furnace at 700°C in a hydrogen atmosphere to obtain ultrafine metal particles as a metal strengthening agent. The raw materials selected were a metal strengthening agent, cobalt / nickel bond phase powder, titanium-containing cubic carbonitride powder, molybdenum carbide powder, and tungsten, tantalum, and niobium carbide powders. The mass percentages of each raw material were as follows: metal strengthening agent 1.5 wt%, cobalt / nickel bond phase powder 15 wt%, titanium-containing cubic carbonitride powder 52.5 wt%, solid solution carbides of tungsten, tantalum, and niobium 10 wt%, and molybdenum carbide powder 2 wt%. The remainder is tungsten carbide, the total mass percentage ratio of each raw material is 100 wt%, and the particle size of the powder is <1.8 μm. A metal reinforcing agent, cobalt / nickel bond phase powder, titanium-containing cubic carbonitride powder, solid solution carbides of tungsten, tantalum, and niobium, molybdenum carbide powder, tungsten carbide, and a molding agent are ball-milled, paraffin (content 2.0 wt%) is used as the molding agent, and anhydrous ethanol is used as the solvent. After ball milling, the mixture is dried to obtain a mixed powder S2. S3 involves press molding the mix to obtain a compacted powder body, A method for producing a high-toughness cermet, comprising S4: heating a compacted body in a vacuum atmosphere to the temperature at which the molding agent is removed, removing the molding agent, heating the compacted body from which the molding agent has been removed to 1150°C in a vacuum atmosphere, then introducing 50 mbar of nitrogen gas, heating and sintering in a nitrogen atmosphere to 1450°C at a heating rate of 6°C / min, then proceeding to vacuum sintering, holding at 1450°C for 1.5 hours, then cooling to 1200°C in a 30 mbar argon atmosphere, and finally cooling under high pressure to room temperature in an argon atmosphere to obtain a cermet.

[0040] Comparative Example 1 The difference from Example 1 is that step S1 was omitted, and a composite powder of Co powder and Ni powder in a mass ratio of 1:1 was used as the binder phase, with the same mass fraction of each component element, and both were added as carbides to produce the cermet material.

[0041] For each example and comparative example, the cermet material obtained was split in half using a "Discotom-100 metal cutting machine," then shrink-fitted with phenolic resin using a "Citpress-20 semi-automatic shrink-fitting device," and finally prepared as a sample using an "AbraPol-20 automatic microprocessor-controlled vertical polishing machine." After polishing with 80, 220, 500, 1200, and 4000 grits respectively, the Vickers hardness HV and fracture toughness Kic were measured on the samples using an "FLC50V-ARS9000 fully automatic micro Vickers hardness tester," and the results are shown in the table below.

[0042] [Table 1]

[0043] The cermet materials obtained in each example and comparative example were cut and shaped to form rough tool materials. The cutting edge of the tool was rounded using a nylon brush containing SiC. A PVD / CVD coating was formed on the surface of the rough tool material to obtain a coated cermet tool.

[0044] The comparative test data and test results for each example and comparative example of coated cermet tools under different cutting conditions are as follows.

[0045] The wear resistance performance of the aforementioned tools was compared by turning a 40CrNi2Mo steel bar in the longitudinal direction. Tool life was defined as the machining time when flank wear was 0.3 mm. See the following table for cutting conditions.

[0046] [Table 2]

[0047] See the following table for detailed test results. [Table 3]

[0048] The test results show that, when processing steel material under continuous cutting conditions, the embodiment of the present invention clearly shows improved wear resistance and cutting edge toughness compared to the comparative example sample. As can be demonstrated, the tool of the embodiment of the present invention can effectively enhance the room-temperature toughness and high-temperature thermal vibration resistance performance of the material. [Explanation of Symbols]

[0049] 1...First hard phase, 2...Second hard phase, 3...Solid solution strengthened binder phase, 4...Micro-nano precipitated phase

Claims

1. A high-toughness cermet comprising a hard phase, a binder phase, and a metal reinforcing agent, (1) A hard phase mainly comprising titanium carbides, nitrides, nitrogen carbides, or any composition thereof, and (2) containing carbides, nitrides, nitrogen carbides, or any composition thereof of at least one metallic element from groups IVB, VB, and VIB of the periodic table other than titanium, and which is nitride if (1) and (2) are different. A bonding phase consisting of at least two transition metals, cobalt, nickel, and iron, A high-toughness cermet characterized by comprising a metal reinforcing agent that is at least two of tantalum, niobium, manganese, ruthenium, rhenium, yttrium, and cerium, and at least one of tantalum, niobium, and manganese, and distributed in a fine and uniform dispersion state within the microstructure of the cermet, wherein the hard phase contains dispersion-reinforced hard phase precipitates comprising at least one of tantalum carbide and niobium carbide, which precipitate when some of the metal elements of the metal reinforcing agent react with carbon, and other some of the metal elements of the metal reinforcing agent solid-solve in the bonded phase to form a solid-solution-reinforced bonded phase.

2. The high-toughness cermet according to claim 1, characterized in that the binding phase accounts for 10 to 24 wt% of the total amount of the cermet, and the hard phase accounts for 76 to 90 wt% of the total amount of the cermet.

3. The high-toughness cermet according to claim 1, characterized in that the particle size of the hard phase is 0.5 to 5.0 μm.

4. The high-toughness cermet according to claim 1, characterized in that tantalum accounts for 0.35 to 6.0 wt% of the total amount of the cermet, niobium accounts for 0.2 to 2.0 wt% of the total amount of the cermet, and manganese accounts for 0.3 to 4.0 wt% of the total amount of the cermet.

5. The high-toughness cermet according to claim 1, characterized in that the mass ratio of tantalum to niobium added to the bonding phase is (1 to 4):

1.

6. The high-toughness cermet according to claim 1, characterized in that the proportion of manganese added to the binding phase in the metal reinforcing agent is ≤50 wt%.

7. The high-toughness cermet according to claim 1, characterized in that, in a photograph of the same scanning electron microscope, the hard phase includes a first hard phase and a second hard phase, where the first hard phase mainly appears as a phase having a black core-gray outer periphery structure and a phase having a black-gray structure, and the first hard phase mainly consists of titanium carbide and / or titanium nitride and / or titanium nitride, the second hard phase mainly appears as a phase having a light-colored core-gray outer periphery structure, the binding phase mainly exhibits a phase having a medium-brightness structure, and a number of micro-nano precipitated phases are deposited in a point-like manner at the interface between the binding phase and the hard phase.

8. A method for producing a high-toughness cermet according to any one of claims 1 to 7. S1 prepares the raw materials for the metal reinforcing agent, (1) mainly consisting of titanium carbides, nitrides, nitrogen carbides, or any composition thereof, and (2) containing carbides, nitrides, nitrogen carbides, or any composition thereof of at least one metallic element from groups IVB, VB, and VIB of the periodic table other than titanium, and if (1) and (2) are different, prepare a hard phase powder which is nitride and a bonding phase powder which is at least two transition metals which are cobalt, nickel, and iron, and then mix the hard phase powder, bonding phase powder, metal reinforcing agent raw material in step S1, solvent and molding agent, and after ball milling again, prepare by spraying to obtain a mix in S2. S3 involves press molding the mix to obtain a compacted powder body, A method for producing a high-toughness cermet, comprising: placing a compacted body in a sintering furnace, raising the temperature to a molding agent removal temperature, removing the molding agent, and then performing low-pressure atmosphere sintering to obtain a high-toughness cermet, wherein the low-pressure atmosphere sintering is specifically characterized by raising the temperature to A, introducing a process gas at x mbar, raising the temperature to B in a nitrogen atmosphere at a heating rate of 2 to 10°C / min, then transitioning to vacuum sintering, holding at B temperature for 0.5 to 3 hours, then cooling to 1200°C in a process gas partial pressure atmosphere of y mbar, and finally high-pressure cooling in an argon atmosphere, wherein the temperature A is 1000 to 1400°C, the temperature B is 1400 to 1600°C, x is 0.5 to 60, y is 10 to 100, and the process gas is at least one selected from nitrogen, argon, and helium, comprising S4.

9. The method for producing a high-toughness cermet according to claim 8, characterized in that in step S1, the metal reinforcing agent raw material is a metal powder, oxide, complex, salt, or any composition thereof of at least two metal elements from among tantalum, niobium, manganese, ruthenium, rhenium, yttrium, and cerium.

10. The method for producing a high-toughness cermet according to claim 9, characterized in that in step S1, a metal reinforcing agent raw material is mixed with a molding agent and a solvent, pulverized using a ball mill, dried, and then subjected to a hydrogen reduction treatment to obtain ultrafine metal particles as a metal reinforcing agent.

11. In step S4, the atmosphere inside the sintering furnace during the molding agent removal process is a hydrogen atmosphere or a vacuum atmosphere. In step S1, when the metal reinforcing agent raw material is subjected to hydrogen reduction treatment, the atmosphere inside the sintering furnace during the molding agent removal process is a vacuum atmosphere. The method for producing a high-toughness cermet according to claim 10, characterized in that, in step S1, when a metal reinforcing agent raw material is used directly, the atmosphere inside the sintering furnace during the molding agent removal process is a hydrogen atmosphere.

12. A cutting tool comprising a substrate made of a high-toughness cermet manufactured using the high-toughness cermet described in any one of claims 1 to 7.

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