Preparation method of high-entropy binder phase Ti(C, N) based cermet material and product thereof

Abstract

The application belongs to the field of powder metallurgy and cermet material, and discloses a preparation method of high-entropy binder phase Ti(C, N) based cermet material and a product thereof. The preparation method uses Fe, Mn, Co and Cr elemental metal powders as raw materials, mixes and performs ball milling to obtain high-entropy alloy powder, and then the high-entropy alloy powder is mixed with Ti(C, N) powder and secondary carbide powder to obtain a mixed powder, and then a forming agent and anhydrous ethanol are sequentially added to perform wet milling to obtain a mixed slurry, which is dried, ground, sieved, pressed, degreased and sintered to obtain the high-entropy alloy Ti(C, N) based cermet material. The obtained high-entropy alloy Ti(C, N) based cermet material has uniformly distributed core-ring structures, and the ring phase transition layer with moderate thickness effectively inhibits the growth of Ti(C, N) grains, achieves fine-grain strengthening and solid solution strengthening, has good bending strength, fracture toughness, high hardness and high density, and can be used for high-speed cutting, finishing and semi-finishing under complex conditions.

Description

A method for preparing high-entropy Ti(C,N)-based cermet materials and its products Technical Field

[0001] This invention belongs to the fields of powder metallurgy technology and metal ceramic materials, and particularly relates to a method for preparing a high-entropy Ti(C,N)-based metal ceramic material and its product. Background Technology

[0002] With the advancement of science and technology, the requirements for the comprehensive performance of materials are becoming increasingly stringent. Compared with traditional cemented carbide materials, Ti(C,N)-based cermet materials possess superior chemical stability, thermal conductivity, high-temperature hardness, wear resistance, and lower density and coefficient of friction. Due to their excellent comprehensive performance, they are widely used in workpiece materials requiring high temperature and high pressure resistance and wear resistance. Traditional Ti(C,N)-based cermets use single pure metals, alloys, or intermetallic compounds such as Ni and Co as binder phases. While these binder phases can improve the toughness, hardness, and wear resistance of cermets to some extent, their performance shortcomings become increasingly apparent when facing increasingly complex and variable working conditions. For traditional cemented carbide or cermet tool materials with Co as the binder phase, the high-temperature softening phenomenon exhibited under high temperature, high pressure, and high cutting speed exacerbates tool wear and shortens tool life. Using alloys and intermetallic compounds as binder phases can increase the relative density of cemented carbide and cermet, but the improvement in their mechanical properties is limited, and they are prone to forming brittle hard phases, reducing the overall performance of the material. Therefore, seeking high-performance binder phases is a key factor in improving the comprehensive performance of cermets.

[0003] High-entropy alloys, as a novel alloy material, break away from traditional alloy design concepts. They have evolved from initially having near-equiatomic ratios of elements or varying within a certain range to non-equiatomic ratios, opening up a wider design space for high-entropy alloys. The unique compositional design of high-entropy alloys endows them with a series of superior properties: thermodynamic high-entropy effects, structural lattice distortion effects, kinetic hysteresis diffusion effects, and performance "cocktail" effects. In high-entropy alloy systems, the higher mixing entropy improves system stability, forming relatively simple solid solutions or amorphous structures, increasing the mutual solubility between components, and avoiding the formation of brittle hard phases between metals. The dissolution of atoms of different sizes into the lattice of high-entropy alloys causes severe lattice distortion, resulting in a solid solution strengthening effect superior to traditional alloys. The coordination of atoms of different sizes hinders dislocation formation, leading to better performance. High-entropy alloys contain multiple principal elements, and the coordination between principal element atoms of different sizes inhibits the diffusion of hard phases, thereby suppressing grain growth. Each component element in a high-entropy alloy exhibits both its own characteristics and complex synergistic effects, allowing for the design of high-entropy alloy compositions according to specific requirements.

[0004] For Ti(C,N)-based cermets, the formed spherical core-shell structure plays a crucial role in their performance. Although the solid solutions of the two are basically the same in structure and lattice parameters, the cyclic phase contains more W, Mo, and binder elements, exhibiting a light color, while the core phase contains more Ti, exhibiting a dark color. The cyclic phase inhibits the Ostwald dissolution and precipitation mechanism of Ti(C,N) particles, achieving grain refinement and solid solution strengthening. However, the thickness of the cyclic phase transition layer needs to be controlled, as it is a brittle phase, and excessive thickness or thinness will affect the performance of the cermet. Patent application CN 118621170 A prepared a bicrystalline cermet structure by adding graphite powder and using virgin carbothermal reduction sintering, achieving high flexural strength. However, the sintering process is time-consuming, increasing energy consumption and cost, and the excessively thick cyclic phase transition layer results in low hardness. The high-entropy carbide ceramics prepared by patent application CN 111850373 A, while exhibiting good flexural strength, suffer from high sintering temperatures and complex sintering processes. High temperatures also tend to generate brittle carbide phases and inhomogeneous cyclic phases, resulting in lower hardness. Therefore, finding a relatively simple and cost-effective preparation method to obtain high-entropy metallic ceramics with a uniformly distributed spherical core-shell structure, a moderately thick cyclic phase transition layer, and good overall mechanical properties is of great significance in this technical field. Summary of the Invention

[0005] The technical problem to be solved by this invention is to overcome the deficiencies and defects mentioned in the background art above, and to provide a method for preparing high-entropy bonded phase Ti(C,N)-based cermets and the products thereof. This invention employs high-energy ball milling and high-temperature gas pressure sintering to form a uniformly distributed spherical core-shell structure and a ring phase of moderate thickness, maintaining high hardness while improving bending strength, fracture toughness, and density.

[0006] To solve the above-mentioned technical problems, the technical solution proposed by this invention is as follows:

[0007] A method for preparing a high-entropy Ti(C,N)-based cermet material with a binder phase includes the following steps:

[0008] (1) Using Fe, Mn, Co and Cr elemental metal powders as raw materials, they are mixed and then ball-milled to prepare high-entropy alloy powder;

[0009] (2) In the mixed powder composed of high entropy alloy powder, Ti(C,N) powder and secondary carbide powder, a forming agent and anhydrous ethanol are added in sequence, and wet milling is performed to obtain a mixed slurry;

[0010] (3) Grind the block material obtained after drying the mixed slurry, sieve it, and press it into blocks;

[0011] (4) The bulk material is degreased and sintered to obtain a high-entropy bonded phase Ti(C,N) based metal ceramic material.

[0012] In the above preparation method, further, in step (1), the mass percentage of the Fe, Mn, Co, and Cr elemental metal powders is Fe: 48.32~52.32wt%, Mn: 27.70~31.70wt%, Co: 8.62~12.62wt%, and Cr: 7.37~11.37wt%.

[0013] Furthermore, the entire operation of step (1) is carried out in a circulating purification glove box filled with nitrogen. The water content in the circulating purification glove box is <0.1ppm, the oxygen content is <0.1ppm, and the nitrogen filling pressure is 1.001atm~1.005atm. The ball mill is an intermittent high-energy ball mill. The ball milling process is dry milling. The grinding balls are WC-Co hard alloy balls. Among them, the number of grinding balls with a diameter of 2~3mm accounts for 25%, the number of grinding balls with a diameter of 4~5mm accounts for 50%, and the number of grinding balls with a diameter of 6~8mm accounts for 25%. The ball-to-material ratio is 10~15:1. The ball milling speed is 350~450rpm. The ball milling time is 60~90h. During this period, there is an interval of 5~10min every 1~2h of ball milling.

[0014] Further, in step (2), the mass percentage of the mixed powder is 100 wt%, of which high-entropy alloy powder accounts for 10-20 wt%, secondary carbide powder accounts for 15-30 wt%, and the balance is Ti(C,N) powder; the secondary carbide powder includes Mo2C, Cr3C2, VC and WC powder, and their mass ratio is 2-3:1.5-3.5:0.5-3.5:12-20; the forming agent is paraffin wax, and its mass is 3-4 wt% of the mass of the mixed powder.

[0015] Furthermore, in step (2), the mass of the anhydrous ethanol is 1.5 to 2 times the mass of the mixed powder; wet grinding for 8 to 10 hours, with a ball-to-powder ratio of 10:1 to 15:1.

[0016] Furthermore, in step (3), the drying is vacuum drying, the vacuum degree is 0.1~20kPa, and the drying temperature is 90~100℃; the sieving is done with a 100~150 mesh standard sieve; and the pressing pressure is 230~250MPa.

[0017] Further, in step (4), the degreasing process is as follows: the block is placed in a degreasing furnace, evacuated to negative pressure, and then filled with argon gas. After the gas pressure in the degreasing furnace cavity reaches 0.1~0.2MPa, the exhaust valve is opened, the temperature is raised to 550~650℃ and held for 3~5 hours for the first degreasing, and then cooled with the furnace. During the process, the intake and exhaust are kept in balance, and the gas pressure is stabilized at 0.1~0.2MPa. After the block is cooled to room temperature with the furnace, it is placed in a vacuum sintering furnace and evacuated to 10℃. -3 ~10-2 After Pa, heat to 550~650℃ and hold for 1.5~2.5h for a second degreasing.

[0018] Furthermore, in step (4), the sintering is high-temperature gas pressure sintering, which includes the following stages:

[0019] Phase 1: Vacuuming to 10 -3 ~10 -2 Pa, heat to 550~650℃, heating rate is 8~10℃ / min, hold for 40~60min;

[0020] Second stage: Heat to 1100~1200℃ at a rate of 7~9℃ / min, hold for 40~60min, and when the temperature reaches 850~900℃, introduce 0.1~0.15MPa of argon gas;

[0021] Third stage: Heat to 1300~1350℃, heating rate is 4~6℃ / min, hold for 30~40min;

[0022] Fourth stage: Heat to 1400~1420℃ at a rate of 4~6℃ / min, introduce argon gas at 4~5MPa, and hold for 60~70min;

[0023] Fifth stage: After the heat preservation is completed, the furnace is cooled to room temperature.

[0024] Based on a general inventive concept, the present invention also provides a high-entropy Ti(C,N)-based cermet material obtained by the preparation method described above, wherein the binder phase is Fe. 50 Mn 30 Co 10 Cr 10 The high-entropy alloy has a hard phase of Ti(C,N) cermet and a binder phase of high-entropy alloy uniformly dispersed between the particles of the hard phase, resulting in a microstructure of the high-entropy binder phase Ti(C,N) based cermet material having a uniformly distributed spherical core-shell structure and a ring-phase transition layer.

[0025] The aforementioned high-entropy bonded phase Ti(C,N)-based cermet material further includes a high-entropy alloy powder before sintering that is a mixture of lamellar and agglomerated powders with an average particle size of 3-8 μm; the average particle size of the high-entropy alloy and Ti(C,N) powder after wet milling is 1-3 μm; and the microstructure of the sintered bulk high-entropy bonded phase Ti(C,N)-based cermet material has a uniformly distributed spherical core-shell structure and a ring-phase transition layer, wherein the average size of the spherical core-shell structure is 0.5-1.5 μm and the average thickness of the ring-phase transition layer is 0.2-0.5 μm.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] 1. This invention uses a high-entropy alloy prepared by high-energy ball milling as a binder phase to increase the sinterability of cermets, achieving higher densification of cermets at a lower sintering temperature, and avoiding the reduction in hardness caused by brittle phases formed at high temperatures.

[0028] 2. This invention prepares high-entropy cermets by employing high-energy ball milling and high-temperature gas pressure sintering, forming a uniformly distributed spherical core-shell structure and a ring-phase transition layer with a thickness of 0.2~0.5μm. This improves the wettability of the high-entropy binder to the hard phase, inhibits the grain growth of the hard phase, and enhances bending strength and fracture toughness. The high-entropy alloy is uniformly dispersed between the hard phases, achieving densification and compositional homogeneity. While maintaining high hardness, it also improves bending strength. The severe lattice distortion and hysteresis diffusion effect of the high-entropy alloy effectively inhibits the grain growth of the hard phase. Crack propagation is deflected and absorbed in various forms, including crack bridging, crack deflection, intergranular fracture, transgranular fracture, and crack branching, thereby enhancing fracture toughness.

[0029] 3. The sintering process of the present invention is short, with low energy consumption and cost; the sintering temperature is low, and the sintering process is simple, avoiding the problems of low hardness caused by the formation of brittle carbide phases and uneven cyclic phases in traditional methods when high-temperature sintering is easy to produce. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 shows the SEM microstructure of the high-entropy metal ceramic prepared in Example 1;

[0032] Figure 2 is a SEM image of crack propagation in Example 1. Detailed Implementation

[0033] This invention provides a high-entropy Ti(C,N)-based cermet material with a binder phase, wherein the binder phase is Fe. 50 Mn 30 Co 10 Cr 10 (at%) High-entropy alloy, with the hard phase being Ti(C,N) cermet, and the binder phase high-entropy alloy uniformly dispersed between the particles of the hard phase Ti(C,N) cermet.

[0034] The method for preparing high-entropy bonded phase Ti(C,N)-based cermet materials is achieved through the following techniques:

[0035] In the composition of the high-entropy cermet, the high-entropy alloy binder phase is introduced by Fe, Mn, Co, and Cr elemental metal powders, and the ceramic hard phase is composed of Ti (C 0.7 N 0.3 The secondary carbide powder is introduced from Mo2C, Cr3C2, VC, and WC powders; high-entropy alloy powder accounts for 10~20wt%, secondary carbide powder accounts for 16~30wt%, of which Mo2C accounts for 2~3wt%, Cr3C2 accounts for 1.5~3.5wt%, VC accounts for 0.5~3.5wt%, and WC accounts for 12~20wt%; the balance is Ti(C,N) powder, and the sum of the mass percentages of all powders is 100wt%. The raw materials of the high-entropy alloy binder phase, converted from atomic percentage Fe:Mn:Co:Cr=5:3:1:1 to mass percentage composition, are: Fe: 48.31~52.31wt%, Mn: 27.70~31.70wt%, Co: 8.62~12.62wt%, Cr: 7.37~11.37wt%; the sum of the mass percentages of each component is 100wt%.

[0036] Furthermore, the preparation method of the high-entropy cermet also includes the following steps:

[0037] (1) Preparation of high-entropy alloy powder:

[0038] High-entropy alloy powder was prepared by mixing Fe, Mn, Co, and Cr elemental metal powders with the following mass percentages: Fe: 48.32~52.32wt%, Mn: 27.70~31.70wt%, Co: 8.62~12.62wt%, and Cr: 7.37~11.37wt% in a ball mill jar and then by intermittent high-energy ball milling.

[0039] (2) Wet milling and mixing: Weigh the high entropy alloy powder, Ti(C,N) powder, secondary carbide powder and molding agent paraffin powder obtained in step (1) with weighing paper and place them in a ball mill jar. Add anhydrous ethanol, wherein the high entropy alloy powder accounts for 10~20wt%, the secondary carbide powder accounts for 15~30wt% (the mass ratio of Mo2C, Cr3C2, VC and WC powder is 2~3∶1.5~3.5∶0.5~3.5∶12~20), and the remainder is Ti(C,N) powder. The sum of the mass percentages of each powder is 100wt%; the mass of the molding agent is 3~4wt% of the total mass; the added anhydrous ethanol is 1.5~2 times the weight of the mixture. Wet mill for 8~10h with a ball-to-material ratio of 10:1. After wet milling, a high entropy alloy metal-ceramic mixed slurry is obtained.

[0040] (3) Place the mixed slurry obtained in step (2) in a vacuum drying oven, evacuate to 0.1~20kPa, dry completely at 100℃, grind the obtained block material, sieve it through a 100~150 mesh standard sieve, and press the sieved powder into blocks using a hydraulic molding machine at 230~250MPa.

[0041] (4) The bulk obtained in step (3) is degreased and sintered to obtain a high-entropy bonded phase Ti(C,N) based metal ceramic.

[0042] Furthermore, the raw materials in step (1) are stored in a circulating purification glove box, and powder is prepared in the circulating purification glove box using a ball mill jar. The water content is <0.1ppm, the oxygen content is <0.1ppm, and the pressure of high-purity N2 in the glove box is 1.001atm~1.005atm.

[0043] Furthermore, the high-energy ball milling in step (1) is carried out in an intermittent planetary ball mill. The ball milling process is dry milling. 25% of the grinding balls are WC-Co hard alloy balls with a diameter of 2~3mm, 50% have a diameter of 4~5mm, and 25% have a diameter of 6~8mm. The ball-to-material ratio is 10:1~15:1. The ball milling speed is 350~450rpm and the ball milling time is 60~90h. During this period, there is a 5~10min interval every 1~2h of ball milling. The weighing, canning, and ball milling of the elemental metal powder are carried out under N2 atmosphere.

[0044] Furthermore, in step (4), the block is placed in a degreasing furnace, evacuated to negative pressure, and then filled with high-purity Ar. After the chamber pressure reaches 0.1~0.2MPa, the exhaust valve is opened, and the temperature is raised to 550~650℃ and held for degreasing for 3~5 hours before cooling with the furnace. During the process, the intake and exhaust are kept in balance, and the pressure is stabilized at 0.1~0.2MPa. After the block cools to room temperature, it is placed in a vacuum sintering furnace and evacuated to 10℃. -3 ~10 -2 After Pa, heat to 550~650℃ and hold for 1.5~2.5h for secondary degreasing.

[0045] Furthermore, step (4) sintering is high-temperature gas pressure sintering, and the sintering process mainly consists of five stages: the first stage is to evacuate the gas pressure sintering furnace to 10 -3 ~10 -2In the first stage, the temperature is raised to 550~650℃ at a rate of 8~10℃ / min and held for 40~60min. In the second stage, the temperature is raised to 1100~1200℃ at a rate of 7~9℃ / min and held for 40~60min, during which 0.1~0.15MPa of high-purity Ar gas is introduced at 850~900℃. In the third stage, the temperature is raised to 1300~1350℃ at a rate of 4~6℃ / min and held for 30~40min. In the fourth stage, the temperature is raised to 1400~1420℃ at a rate of 4~6℃ / min, 4~5MPa of high-purity Ar gas is introduced and held for 60~70min. In the fifth stage, the furnace is cooled to room temperature after the holding period.

[0046] To achieve this objective, in step (1) above, high-energy ball milling is used to prepare a high-entropy alloy from mixed metal powder. By controlling the ball milling time or speed, the desired high-entropy alloy powder with a relative content of two phases is obtained. During the high-energy ball milling process, the metal powder is repeatedly deformed, fractured, and cold-welded, and the grains are continuously refined, which is beneficial to the subsequent improvement of strength, hardness, and toughness. The continuous and intense impact, friction, and shearing of the metal powder by the high-energy grinding balls fully and uniformly mixes the powder of each metal element to form a solid solution, forming a high-entropy alloy powder with uniform composition. The powder is presented in lamellar and clump form, with an average particle size of 5 μm. During the ball milling process, the metal powder generates a large number of crystal defects, which store distortion energy at the high-entropy grain boundaries, reduce the temperature driving the dissolution and re-precipitation of the hard phase, and shorten the sintering time.

[0047] To achieve this objective, a nitrogen-filled circulating purification glove box is used for powder preparation to avoid oxidation and contamination of the original high-entropy alloy powder. A high-purity N2 atmosphere is used to fill the ball mill jar to prevent oxidation of active metal elements during the ball milling process. Degreasing is performed in a degreasing furnace and a secondary degreasing in a vacuum furnace to ensure complete evaporation and discharge of the forming agent, minimizing its impact on performance. Drying is carried out in a vacuum drying oven, with repeated evacuation to negative pressure to more quickly evaporate and discharge alcohol, shorten drying time, prevent oxidation of active metals upon contact with air, and maintain the quality and purity of the powder.

[0048] To achieve this objective, the high-temperature pressure sintering process mainly consists of five stages, the first stage being vacuuming to 10... -3 ~10 -2After the initial heating, the temperature is raised to 550-650℃ at a rate of 8-10℃ / min and held for 40-60min. This stage allows the sintered block to be fully preheated and further removes residual forming agent, ensuring complete removal and minimizing its impact on subsequent sintering processes. In the second stage, the temperature is raised to 1100-1200℃ at a rate of 7-9℃ / min and held for 40-60min. Then, a high pressure of 0.1-0.15MPa is applied at 850-900℃. In the first stage, pure Ar is used. This stage is mainly solid-state sintering. The high-entropy binder phase and the hard ceramic phase increase the contact area, gradually strengthening the bonding between particles and increasing density. The introduction of Ar suppresses the volatilization of low-melting-point elements, ensuring the sintering performance of the binder phase. In the third stage, the temperature is raised to 1300~1350℃ at a rate of 4~6℃ / min and held for 30~40min. This stage mainly allows the high-entropy binder phase, which already has a liquid phase, to fill the spaces between the hard phases through capillary forces and its excellent fluidity, reducing the hardness of the phase. As the phase grains grow and expel the trapped gases, the density and miscibility are further improved, and the bonding strength is enhanced. In the fourth stage, the temperature is raised to 1400~1420℃ at a rate of 4~6℃ / min, and high-purity Ar gas at 4~5MPa is introduced. The temperature is held for 60~70min. This stage is the liquid phase sintering stage, in which the Ostwald dissolution and precipitation mechanism occurs. The solid solution and re-precipitation process gives the core-ring structure a spatial spherical morphology. The formation of the solid solution makes the interface between the hard phase and the binder phase more uniform. The binder phase releases the stress after ball milling, reduces interfacial stress concentration, and enhances the bonding force between the two phases. Furthermore, the lattice distortion of the high-entropy alloy prevents grain growth, resulting in a more compact microstructure. After the fifth stage of heat preservation, the furnace is cooled to room temperature. Rapid cooling inhibits the growth of solid solution grains in the hard phase and binder phase, reduces the formation of coarse-grained brittle hard phases, and the lattice distortion and rapid cooling between the binder phase and hard phase effectively inhibit the re-precipitation of solutes in the hard phase. Fine grain strengthening and solid solution strengthening improve the overall mechanical properties.

[0049] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0050] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0051] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0052] The raw materials used in the following examples have a purity of ≥99.9% and include: Fe powder (2μm), Mn powder (20μm), Co powder (2μm), Cr powder (45μm), Ti (C,N) powder (1.5~2.0μm), and secondary carbide powder (1.0~3.0μm).

[0053] Table 1. Weight percentage (wt%) of each metal powder in the high-entropy alloy binder phase for each embodiment.

[0054]

[0055] Table 2. Weight percentage (wt%) of high-entropy alloy powder, Ti(C,N) powder, and secondary carbide powder weighed in each embodiment.

[0056]

[0057] Example 1

[0058] A method for preparing a high-entropy Ti(C,N)-based cermet material with a binder phase includes the following steps:

[0059] (1) Using Fe, Mn, Co, and Cr elemental metal powders as raw materials, the mixture prepared according to the proportions in Table 1 is placed in a ball mill jar in a circulating purification glove box filled with nitrogen (nitrogen filling pressure is 1.001 atm~1.005 atm). The ball-to-material ratio is 10:1, the ball mill speed is 400 rpm, the ball milling time is 60 h, and the ball milling interval is 10 min every 60 min.

[0060] (2) Weigh the high entropy alloy powder, Ti(C,N) powder, secondary carbide powder and molding agent paraffin powder obtained by ball milling according to Table 2 using weighing paper, place them in a ball milling jar, add appropriate anhydrous ethanol, wet mill for 10 hours, with a 10-minute interval every 60 minutes, ball-to-material ratio of 10:1, and obtain a high entropy alloy metal-ceramic mixed slurry after ball milling.

[0061] (3) The mixed slurry is completely dried in a vacuum drying oven at 100°C. The dried block material is ground and sieved through a 100-mesh sieve. It is then pressed into blocks by a hydraulic molding machine at 250 MPa.

[0062] (4) Degrease the sample by holding it at 600℃ for 5 hours in a degreasing furnace, maintaining high-purity Ar gas during both filling and exhaust, and keeping the gas pressure at approximately 0.15 MPa. After the holding period, close the gas valve and allow the furnace to cool to complete the first degreasing step. After removing the sample, place it in a vacuum sintering furnace and raise the temperature to 600℃ at 5℃ / min, holding it for 120 minutes. After the holding period, allow the furnace to cool to complete the second degreasing step. Place the block after the second degreasing step in a pressure sintering furnace and evacuate it to 10℃. -2The furnace was heated to 600℃ in 60 min at a rate of 10℃ / min and held for 40 min; then heated to 1100℃ in 60 min at a rate of 8.3℃ / min and held for 40 min. During this heating process, when the temperature reached 850℃, 0.112 MPa of high-purity Ar was introduced; the furnace was heated to 1300℃ in 50 min at a rate of 4℃ / min and held for 35 min; then heated to 1400℃ in 25 min at a rate of 4℃ / min and held for 70 min, and 4.011 MPa of high-purity Ar gas was introduced. After the holding period, the furnace was cooled to room temperature to obtain a high-entropy bonded phase Ti(C,N) based metal ceramic bulk.

[0063] In this embodiment, the high-entropy alloy powder is in the form of sheets and clumps, with an average particle size of 4.55±0.36μm. The average particle size of the high-entropy alloy and Ti(C,N) powder after wet milling is 1.68±0.45μm. The microstructure of the bulk high-entropy bonded phase Ti(C,N)-based cermet material obtained after sintering has a uniformly distributed spherical core-shell structure and a ring-phase transition layer.

[0064] As shown in Figures 1 and 2, the high-entropy Ti(C,N)-based cermet material prepared by this invention forms a uniformly distributed spherical core-shell structure and a ring-phase transition layer of moderate thickness. The average size of the core-shell structure is 0.86±0.33μm, and the average thickness of the transition layer is 0.30±0.08μm. The ring-phase improves the wettability of the binder phase to the hard phase, inhibits the growth of hard phase grains, and improves the bending strength and fracture toughness of the cermet. The high-entropy alloy is uniformly dispersed between the hard phases, achieving densification and compositional homogeneity. While maintaining high hardness, it improves bending strength. The severe lattice distortion and hysteresis diffusion effect of the high-entropy alloy effectively inhibits the growth of hard phase grains. In Figure 2, crack propagation is deflected and absorbed in various forms such as crack bridging, crack deflection, intergranular fracture, transgranular fracture, and crack branching to enhance fracture toughness.

[0065] The parameters of the metal ceramics prepared under the above preparation process conditions are shown in Table 3.

[0066] Table 3 shows the mechanical properties and relative density of the metal ceramics prepared using Example 1.

[0067]

[0068] Example 2

[0069] A method for preparing a high-entropy Ti(C,N)-based cermet material with a binder phase includes the following steps:

[0070] (1) Using Fe, Mn, Co, and Cr elemental metal powders as raw materials, the mixture prepared according to the proportions in Table 1 is placed in a ball mill jar in a circulating purification glove box filled with nitrogen (nitrogen filling pressure is 1.001 atm~1.005 atm). The ball-to-material ratio is 12:1, the ball mill speed is 400 rpm, the ball milling time is 65 h, and the ball milling interval is 10 min every 60 min.

[0071] (2) Weigh the high entropy alloy powder, Ti(C,N) powder, secondary carbide powder and molding agent paraffin powder obtained by ball milling according to Table 2 using weighing paper, place them in a ball milling jar, add appropriate anhydrous ethanol, wet mill for 10 hours, with a 10-minute interval every 60 minutes, ball-to-material ratio of 12:1, and obtain a high entropy alloy metal-ceramic mixed slurry after ball milling.

[0072] (3) The mixed slurry is completely dried in a vacuum drying oven at 100°C. The dried block material is ground and sieved through a 100-mesh sieve. It is then pressed into blocks by a hydraulic molding machine at 250 MPa.

[0073] (4) Degrease the sample by holding it at 600℃ for 5 hours in a degreasing furnace, maintaining high-purity Ar gas during both filling and exhaust, and keeping the gas pressure at approximately 0.15 MPa. After the holding period, close the gas valve and allow the furnace to cool to complete the first degreasing step. After removing the sample, place it in a vacuum sintering furnace and raise the temperature to 600℃ at 5℃ / min, holding it for 120 minutes. After the holding period, allow the furnace to cool to complete the second degreasing step. Place the block after the second degreasing step in a pressure sintering furnace and evacuate it to 10℃. -2 The furnace was heated to 600℃ in 60 min at a rate of 10℃ / min and held for 40 min; then heated to 1100℃ in 60 min at a rate of 8.3℃ / min and held for 40 min. During this heating process, when the temperature reached 850℃, 0.125 MPa of high-purity Ar was introduced; the furnace was heated to 1300℃ in 50 min at a rate of 4℃ / min and held for 35 min; then heated to 1400℃ in 25 min at a rate of 4℃ / min and held for 70 min, and 4.211 MPa of high-purity Ar gas was introduced. After the holding period, the furnace was cooled to room temperature to obtain a high-entropy bonded phase Ti(C,N) based metal ceramic bulk.

[0074] In this embodiment, the high-entropy alloy powder is in the form of sheets and clumps, with an average particle size of 4.48±0.32μm. The average particle size of the high-entropy alloy and Ti(C,N) powder after wet milling is 1.61±0.24μm. The microstructure of the bulk high-entropy bonded phase Ti(C,N)-based cermet material obtained after sintering has a uniformly distributed spherical core-shell structure and a ring-phase transition layer.

[0075] The high-entropy Ti(C,N)-based cermet material prepared by this invention forms a uniformly distributed spherical core-shell structure and a ring-phase transition layer of moderate thickness. The average size of the core-shell structure is 0.93±0.15μm, and the average thickness of the transition layer is 0.28±0.05μm. The ring-phase improves the wettability of the binder phase to the hard phase, inhibits the growth of hard phase grains, and improves the bending strength and fracture toughness of the cermet. The high-entropy alloy is uniformly dispersed between the hard phases, achieving densification and compositional homogeneity. While maintaining high hardness, it improves bending strength. The severe lattice distortion and hysteresis diffusion effect of the high-entropy alloy effectively inhibits the growth of hard phase grains, and the hard phase grains are deflected and absorbed in various forms such as crack bridging, crack deflection, intergranular fracture, transgranular fracture, and crack branching to enhance fracture toughness.

[0076] The parameters of the metal ceramics prepared under the above preparation process conditions are shown in Table 4.

[0077] Table 4 shows the mechanical properties and relative density of the metal ceramics prepared in Example 2.

[0078]

[0079] Example 3

[0080] A method for preparing a high-entropy Ti(C,N)-based cermet material with a binder phase includes the following steps:

[0081] (1) Using Fe, Mn, Co, and Cr elemental metal powders as raw materials, the mixture prepared according to the proportions in Table 1 is placed in a ball mill jar in a circulating purification glove box filled with nitrogen (nitrogen filling pressure is 1.001 atm~1.005 atm). The ball-to-material ratio is 12:1, the ball mill speed is 400 rpm, the ball milling time is 70 h, and the ball milling interval is 10 min every 60 min.

[0082] (2) Weigh the high entropy alloy powder, Ti(C,N) powder, secondary carbide powder and molding agent paraffin powder obtained by ball milling according to Table 2 using weighing paper, place them in a ball milling jar, add appropriate anhydrous ethanol, wet mill for 10 hours, with a 10-minute interval every 60 minutes, ball-to-material ratio of 10:1, and obtain a high entropy alloy metal-ceramic mixed slurry after ball milling.

[0083] (3) The mixed slurry is completely dried in a vacuum drying oven at 100°C. The dried block material is ground and sieved through a 100-mesh sieve. It is then pressed into blocks by a hydraulic molding machine at 250 MPa.

[0084] (4) Degrease the sample by holding it at 600℃ for 5 hours in a degreasing furnace, maintaining high-purity Ar gas during both filling and exhaust, and keeping the gas pressure at approximately 0.15 MPa. After the holding period, close the gas valve and allow the furnace to cool to complete the first degreasing step. After removing the sample, place it in a vacuum sintering furnace and raise the temperature to 630℃ at a rate of 5℃ / min, holding it for 120 minutes. After the holding period, allow the furnace to cool to complete the second degreasing step. Place the block after the second degreasing step in a pressure sintering furnace and evacuate it to 10℃. -3 The temperature was increased to 630℃ in 70 min at a rate of 9℃ / min and held for 60 min; then increased to 1100℃ in 50 min at a rate of 9.4℃ / min and held for 60 min. During this heating process, when the temperature reached 860℃, 0.132 MPa of high-purity Ar was introduced; the temperature was increased to 1350℃ in 60 min at a rate of 4.2℃ / min and held for 40 min; then increased to 1410℃ in 12 min at a rate of 5℃ / min and held for 70 min, and 5 MPa of high-purity Ar gas was introduced. After the holding period, the furnace was cooled to room temperature to obtain a high-entropy bonded phase Ti(C,N) based metal ceramic bulk.

[0085] In this embodiment, the high-entropy alloy powder is in the form of sheets and clumps, with an average particle size of 3.75±0.36μm. The average particle size of the high-entropy alloy and Ti(C,N) powder after wet milling is 1.68±0.45μm. The microstructure of the bulk high-entropy bonded phase Ti(C,N) based cermet material obtained after sintering has a uniformly distributed spherical core-shell structure and a ring-phase transition layer.

[0086] The high-entropy Ti(C,N)-based cermet material prepared by this invention forms a uniformly distributed spherical core-shell structure and a ring-phase transition layer of moderate thickness. The average size of the core-shell structure is 0.65±0.12μm, and the average thickness of the transition layer is 0.22±0.03μm. The ring-phase improves the wettability of the binder phase to the hard phase, inhibits the growth of hard phase grains, and improves the bending strength and fracture toughness of the cermet. The high-entropy alloy is uniformly dispersed between the hard phases, achieving densification and compositional homogeneity. While maintaining high hardness, it improves bending strength. The severe lattice distortion and hysteresis diffusion effect of the high-entropy alloy effectively inhibits the growth of hard phase grains, and the hard phase grains are deflected and absorbed in various forms such as crack bridging, crack deflection, intergranular fracture, transgranular fracture, and crack branching to enhance fracture toughness.

[0087] The parameters of the metal ceramics prepared under the above preparation process conditions are shown in Table 5.

[0088] Table 5 shows the mechanical properties and relative density of the metal ceramics prepared in Example 3.

[0089]

[0090] Example 4

[0091] A method for preparing a high-entropy Ti(C,N)-based cermet material with a binder phase includes the following steps:

[0092] (1) Using Fe, Mn, Co, and Cr elemental metal powders as raw materials, the mixture prepared according to the proportions in Table 1 is placed in a ball mill jar in a circulating purification glove box filled with nitrogen (nitrogen filling pressure is 1.001 atm~1.005 atm). The ball-to-material ratio is 12:1, the ball mill speed is 400 rpm, the ball milling time is 75 h, and the ball milling interval is 10 min every 60 min.

[0093] (2) Weigh the high-entropy alloy powder, Ti(C,N) powder, secondary carbide powder and molding agent paraffin powder obtained by ball milling according to Table 2 using weighing paper, place them in a ball milling jar, add appropriate anhydrous ethanol, wet mill for 10 hours, with a 10-minute interval every 60 minutes, and obtain a high-entropy alloy metal ceramic mixed slurry after ball milling.

[0094] (3) The mixed slurry is completely dried in a vacuum drying oven at 100°C. The dried block material is ground and sieved through a 100-mesh sieve. It is then pressed into blocks by a hydraulic molding machine at 250 MPa.

[0095] (4) Degrease the sample by holding it at 600℃ for 5 hours in a degreasing furnace, maintaining high-purity Ar gas during both filling and exhaust, and keeping the gas pressure at approximately 0.15 MPa. After the holding period, close the gas valve and allow the furnace to cool to complete the first degreasing step. After removing the sample, place it in a vacuum sintering furnace and raise the temperature to 630℃ at a rate of 5℃ / min, holding it for 120 minutes. After the holding period, allow the furnace to cool to complete the second degreasing step. Place the block after the second degreasing step in a pressure sintering furnace and evacuate it to 10℃. -3 The temperature was increased to 630℃ in 70 min at a rate of 9℃ / min and held for 60 min; then increased to 1100℃ in 50 min at a rate of 9.4℃ / min and held for 60 min. During this heating process, when the temperature reached 860℃, 0.132 MPa of high-purity Ar was introduced; the temperature was increased to 1350℃ in 60 min at a rate of 4.2℃ / min and held for 40 min; then increased to 1410℃ in 12 min at a rate of 5℃ / min and held for 70 min, and 5 MPa of high-purity Ar gas was introduced. After the holding period, the furnace was cooled to room temperature to obtain a high-entropy bonded phase Ti(C,N) based metal ceramic bulk.

[0096] In this embodiment, the high-entropy alloy powder is in the form of sheets and clumps, with an average particle size of 3.55±0.20μm. The average particle size of the high-entropy alloy and Ti(C,N) powder after wet milling is 1.53±0.24μm. The microstructure of the bulk high-entropy bonded phase Ti(C,N) based cermet material obtained after sintering has a uniformly distributed spherical core-shell structure and a ring-phase transition layer.

[0097] The high-entropy Ti(C,N)-based cermet material prepared by this invention forms a uniformly distributed spherical core-shell structure and a ring-phase transition layer of moderate thickness. The average size of the core-shell structure is 0.64±0.14μm, and the average thickness of the transition layer is 0.21±0.04μm. The ring-phase improves the wettability of the binder phase to the hard phase, inhibits the growth of hard phase grains, and improves the bending strength and fracture toughness of the cermet. The high-entropy alloy is uniformly dispersed between the hard phases, achieving densification and compositional homogeneity. While maintaining high hardness, it improves bending strength. The severe lattice distortion and hysteresis diffusion effect of the high-entropy alloy effectively inhibits the growth of hard phase grains, and the hard phase grains are deflected and absorbed in various forms such as crack bridging, crack deflection, intergranular fracture, transgranular fracture, and crack branching to enhance fracture toughness.

[0098] The parameters of the metal ceramics prepared under the above preparation process conditions are shown in Table 6.

[0099] Table 6 shows the mechanical properties and relative density of the metal ceramics prepared using Example 4.

[0100]

[0101] Example 5:

[0102] A method for preparing a high-entropy Ti(C,N)-based cermet material with a binder phase includes the following steps:

[0103] (1) Using Fe, Mn, Co, and Cr elemental metal powders as raw materials, the mixture prepared according to the proportions in Table 1 is placed in a ball mill jar in a circulating purification glove box filled with nitrogen (nitrogen filling pressure is 1.001 atm~1.005 atm). The ball-to-material ratio is 15:1, the ball mill speed is 400 rpm, the ball milling time is 80 h, and the ball milling interval is 10 min every 60 min.

[0104] (2) Weigh the high-entropy alloy powder, Ti(C,N) powder, secondary carbide powder and molding agent paraffin powder obtained by ball milling according to Table 2 using weighing paper, place them in a ball milling jar, add appropriate anhydrous ethanol, wet mill for 10 hours, with a 10-minute interval every 60 minutes, and obtain a high-entropy alloy metal ceramic mixed slurry after ball milling.

[0105] (3) The mixed slurry is completely dried in a vacuum drying oven at 100°C. The dried block material is ground and sieved through a 100-mesh sieve. It is then pressed into blocks by a hydraulic molding machine at 250 MPa.

[0106] (4) Degrease the sample by holding it at 600℃ for 5 hours in a degreasing furnace, maintaining high-purity Ar gas during both filling and exhaust, and keeping the gas pressure at approximately 0.15 MPa. After the holding period, close the gas valve and allow the furnace to cool down to complete the first degreasing step. After removing the sample, place it in a vacuum sintering furnace and raise the temperature to 650℃ at a rate of 5℃ / min, holding it for 120 minutes. After the holding period, allow the furnace to cool down to complete the second degreasing step. Place the block after the second degreasing step in a pressure sintering furnace and evacuate it to 10℃. -3 The temperature was increased to 650℃ in 70 min at a rate of 9.3℃ / min and held for 40 min; then increased to 1100℃ in 50 min at a rate of 9℃ / min and held for 40 min. During this heating process, when the temperature reached 900℃, 0.142 MPa of high-purity Ar was introduced; the temperature was increased to 1350℃ in 50 min at a rate of 5℃ / min and held for 40 min; then increased to 1420℃ in 16 min at a rate of 4.4℃ / min and held for 60 min, while 4.854 MPa of high-purity Ar gas was introduced. After the holding period, the furnace was cooled to room temperature to obtain a high-entropy bonded phase Ti(C,N) based metal ceramic bulk.

[0107] In this embodiment, the high-entropy alloy powder is in the form of sheets and clumps, with an average particle size of 4.01±0.54μm. The average particle size of the high-entropy alloy and Ti(C,N) powder after wet milling is 1.79±0.35μm. The microstructure of the bulk high-entropy bonded phase Ti(C,N)-based cermet material obtained after sintering has a uniformly distributed spherical core-shell structure and a ring-phase transition layer.

[0108] The high-entropy binder phase Ti(C,N)-based cermet material prepared by this invention forms a uniformly distributed spherical core-shell structure and a ring-phase transition layer of moderate thickness. The average size of the core-shell structure is 0.77±0.10μm, and the average thickness of the transition layer is 0.34±0.06μm. The ring-phase improves the wettability of the binder phase to the hard phase, inhibits the growth of hard phase grains, and improves the bending strength and fracture toughness of the cermet. The high-entropy alloy is uniformly dispersed between the hard phases, achieving densification and compositional homogeneity. While maintaining high hardness, it improves bending strength. The severe lattice distortion and hysteresis diffusion effect of the high-entropy alloy effectively inhibits the growth of hard phase grains, and the hard phase grains are deflected and absorbed in various forms such as crack bridging, crack deflection, intergranular fracture, transgranular fracture, and crack branching to enhance fracture toughness.

[0109] The parameters of the metal ceramics prepared under the above preparation process conditions are shown in Table 7.

[0110] Table 7 shows the mechanical properties and relative density of the cermets prepared using Example 5.

[0111]

[0112] Example 6

[0113] A method for preparing a high-entropy Ti(C,N)-based cermet material with a binder phase includes the following steps:

[0114] (1) Using Fe, Mn, Co, and Cr elemental metal powders as raw materials, the mixture prepared according to the proportions in Table 1 is placed in a ball mill jar in a circulating purification glove box filled with nitrogen (nitrogen filling pressure is 1.001 atm~1.005 atm). The ball-to-material ratio is 15:1, the ball mill speed is 400 rpm, the ball milling time is 85 h, and the ball milling interval is 10 min every 60 min.

[0115] (2) Weigh the high-entropy alloy powder, Ti(C,N) powder, secondary carbide powder and molding agent paraffin powder obtained by ball milling according to Table 2 using weighing paper, place them in a ball milling jar, add appropriate anhydrous ethanol, wet mill for 10 hours, with a 10-minute interval every 60 minutes, and obtain a high-entropy alloy metal ceramic mixed slurry after ball milling.

[0116] (3) The mixed slurry is completely dried in a vacuum drying oven at 100°C. The dried block material is ground and sieved through a 100-mesh sieve. It is then pressed into blocks by a hydraulic molding machine at 250 MPa.

[0117] (4) Degrease the sample by holding it at 600℃ for 5 hours in a degreasing furnace, maintaining high-purity Ar gas during both filling and exhaust, and keeping the gas pressure at approximately 0.15 MPa. After the holding period, close the gas valve and allow the furnace to cool down to complete the first degreasing step. After removing the sample, place it in a vacuum sintering furnace and raise the temperature to 650℃ at a rate of 5℃ / min, holding it for 120 minutes. After the holding period, allow the furnace to cool down to complete the second degreasing step. Place the block after the second degreasing step in a pressure sintering furnace and evacuate it to 10℃. -3 The furnace was heated to 650℃ in 70 min at a rate of 9.3℃ / min and held for 40 min; then heated to 1100℃ in 50 min at a rate of 9℃ / min and held for 40 min. During this heating process, when the temperature reached 900℃, 0.150 MPa of high-purity Ar was introduced; the furnace was heated to 1350℃ in 50 min at a rate of 5℃ / min and held for 40 min; then heated to 1420℃ in 15 min at a rate of 4.7℃ / min and held for 60 min, while 4.931 MPa of high-purity Ar gas was introduced. After the holding period, the furnace was cooled to room temperature to obtain a high-entropy bonded phase Ti(C,N) based metal ceramic bulk.

[0118] In this embodiment, the high-entropy alloy powder is in the form of sheets and clumps, with an average particle size of 4.13±0.44μm. The average particle size of the high-entropy alloy and Ti(C,N) powder after wet milling is 1.74±0.27μm. The microstructure of the bulk high-entropy bonded phase Ti(C,N)-based cermet material obtained after sintering has a uniformly distributed spherical core-shell structure and a ring-phase transition layer.

[0119] The high-entropy Ti(C,N)-based cermet material prepared by this invention forms a uniformly distributed spherical core-shell structure and a ring-phase transition layer of moderate thickness. The average size of the core-shell structure is 0.82±0.11μm, and the average thickness of the transition layer is 0.33±0.05μm. The ring-phase improves the wettability of the binder phase to the hard phase, inhibits the growth of hard phase grains, and improves the bending strength and fracture toughness of the cermet. The high-entropy alloy is uniformly dispersed between the hard phases, achieving densification and compositional homogeneity. While maintaining high hardness, it improves bending strength. The severe lattice distortion and hysteresis diffusion effect of the high-entropy alloy effectively inhibits the growth of hard phase grains, and the hard phase grains are deflected and absorbed in various forms such as crack bridging, crack deflection, intergranular fracture, transgranular fracture, and crack branching to enhance fracture toughness.

[0120] The parameters of the metal ceramics prepared under the above preparation process conditions are shown in Table 8.

[0121] Table 8 shows the mechanical properties and relative density of the metal ceramics prepared using Example 6.

[0122]

[0123] Comparative Example 1

[0124] A method for preparing a high-entropy Ti(C,N)-based cermet material with a binder phase includes the following steps:

[0125] (1) Using Fe, Mn, Co, and Cr elemental metal powders as raw materials, the mixture prepared according to the proportions in Table 1 is placed in a ball mill jar in a circulating purification glove box filled with nitrogen (nitrogen filling pressure is 1.001 atm~1.005 atm). The ball-to-material ratio is 10:1, the ball mill speed is 400 rpm, the ball milling time is 60 h, and the ball milling interval is 10 min every 60 min.

[0126] (2) Weigh the high-entropy alloy powder, Ti(C,N) powder, secondary carbide powder and molding agent paraffin powder obtained by ball milling according to Table 2 using weighing paper, place them in a ball milling jar, add appropriate anhydrous ethanol, wet mill for 10 hours, with a 10-minute interval every 60 minutes, and obtain a high-entropy alloy metal ceramic mixed slurry after ball milling.

[0127] (3) The mixed slurry is completely dried in a vacuum drying oven at 100°C. The dried block material is ground and sieved through a 100-mesh sieve. It is then pressed into blocks by a hydraulic molding machine at 250 MPa.

[0128] (4) Degrease the sample by holding it at 600℃ for 5 hours in a degreasing furnace, maintaining high-purity Ar gas during both filling and exhaust, and keeping the gas pressure at approximately 0.15 MPa. After the holding period, close the gas valve and allow the furnace to cool to complete the first degreasing step. After removing the sample, place it in a vacuum sintering furnace and raise the temperature to 600℃ at 5℃ / min, holding it for 120 minutes. After the holding period, allow the furnace to cool to complete the second degreasing step. Place the block after the second degreasing step in a pressure sintering furnace and evacuate it to 10℃. -3 The temperature was increased to 600℃ in 60 min at a rate of 10℃ / min and held for 40 min; then increased to 1100℃ in 60 min at a rate of 8.3℃ / min and held for 40 min. During this heating process, when the temperature reached 850℃, 0.110 MPa of high-purity Ar was introduced; the temperature was increased to 1300℃ in 50 min at a rate of 4℃ / min and held for 35 min; then increased to 1400℃ in 25 min at a rate of 4℃ / min and held for 70 min, and 4.120 MPa of high-purity Ar gas was introduced. After the holding period, the furnace was cooled to room temperature to obtain a high-entropy bonded phase Ti(C,N) based metal ceramic bulk.

[0129] In Comparative Example 1, the high-entropy binder phase content of the cermet is low, which easily leads to internal defects in the green body during the pressing process and increases internal stress and surface damage during demolding. After sintering, the core-shell structure formed by hard phase particles in the cermet is not obvious. The low binder phase content has a poor inhibitory effect on grain growth, resulting in some hard phase particles being relatively large, reaching 4.86±1.89μm. The flow effect of the binder phase is insufficient, resulting in the agglomeration of the hard phase, poor distribution uniformity, and insufficient filling between hard phase particles. The low binder phase also weakens the inhibition of crack propagation, leading to lower strength, fracture toughness, and relative density.

[0130] The parameters of the metal ceramics prepared under the above preparation process conditions are shown in Table 9.

[0131] Table 9 shows the mechanical properties and relative density of the cermets prepared using Comparative Example 1.

[0132]

[0133] Comparative Example 2

[0134] A method for preparing a high-entropy Ti(C,N)-based cermet material with a binder phase includes the following steps:

[0135] (1) Using Fe, Mn, Co and Cr elemental metal powders as raw materials, the mixture prepared according to the ratio in Table 1 in the circulating purification glove box is placed in the ball mill jar. The ball-to-material ratio is 12:1, the ball mill speed is 400 rpm, the ball milling time is 75 h, and the ball milling interval is 10 min every 60 min.

[0136] (2) Weigh the high-entropy alloy powder, Ti(C,N) powder, secondary carbide powder and molding agent paraffin powder obtained by ball milling according to Table 2 using weighing paper, place them in a ball milling jar, add appropriate anhydrous ethanol, wet mill for 10 hours, with a 10-minute interval every 60 minutes, and obtain a high-entropy alloy metal ceramic mixed slurry after ball milling.

[0137] (3) The mixed slurry is completely dried in a vacuum drying oven at 100°C. The dried block material is ground and sieved through a 100-mesh sieve. It is then pressed into blocks by a hydraulic molding machine at 250 MPa.

[0138] (4) Degrease the sample by holding it at 600℃ for 5 hours in a degreasing furnace, maintaining high-purity Ar gas during both filling and exhaust, and keeping the gas pressure at approximately 0.15 MPa. After the holding period, close the gas valve and allow the furnace to cool down to complete the first degreasing step. After removing the sample, place it in a vacuum sintering furnace and raise the temperature to 650℃ at a rate of 5℃ / min, holding it for 120 minutes. After the holding period, allow the furnace to cool down to complete the second degreasing step. Place the block after the second degreasing step in a pressure sintering furnace and evacuate it to 10℃. -3 The temperature was increased to 630℃ in 70 min at a rate of 9℃ / min and held for 40 min; then increased to 1100℃ in 60 min at a rate of 7.8℃ / min and held for 40 min. During this heating process, when the temperature reached 860℃, 0.128 MPa of high-purity Ar was introduced; the temperature was increased to 1350℃ in 60 min at a rate of 4.2℃ / min and held for 40 min; then increased to 1410℃ in 15 min at a rate of 4℃ / min and held for 70 min, and 5 MPa of high-purity Ar gas was introduced. After the holding period, the furnace was cooled to room temperature to obtain a high-entropy bonded phase Ti(C,N) based metal ceramic bulk.

[0139] The high Mo2C content in the cermet in Comparative Example 2 led to the agglomeration and enrichment of Cr, Mn, Mo, and W elements in the high-entropy binder phase after sintering. The binder phase could not play a good role, and the core-shell structure formed by the hard phase was more obvious, but the size and distribution were uneven, with an average size of 1.42±0.82μm. The transition layer was also too thin, less than 0.1μm. These factors resulted in its low strength, fracture toughness, and relative density.

[0140] The parameters of the metal ceramics prepared under the above preparation process conditions are shown in Table 10.

[0141] Table 10 shows the mechanical properties and relative density of the metal ceramics prepared using Comparative Example 2.

[0142]

[0143] Comparative Example 3

[0144] A method for preparing a high-entropy Ti(C,N)-based cermet material with a binder phase includes the following steps:

[0145] (1) Using Fe, Mn, Co and Cr elemental metal powders as raw materials, the mixture prepared according to the ratio in Table 1 in the circulating purification glove box is placed in the ball mill jar. The ball-to-material ratio is 15:1, the ball mill speed is 400 rpm, the ball milling time is 85 h, and the ball milling interval is 10 min every 60 min.

[0146] (2) Weigh the high-entropy alloy powder, Ti(C,N) powder, secondary carbide powder and molding agent paraffin powder obtained by ball milling according to Table 2 using weighing paper, place them in a ball milling jar, add appropriate anhydrous ethanol, wet mill for 10 hours, with a 10-minute interval every 60 minutes, and obtain a high-entropy alloy metal ceramic mixed slurry after ball milling.

[0147] (3) The mixed slurry is completely dried in a vacuum drying oven at 100°C. The dried block material is ground and sieved through a 100-mesh sieve. It is then pressed into blocks by a hydraulic molding machine at 250 MPa.

[0148] (4) Degrease the sample by holding it at 600℃ for 5 hours in a degreasing furnace, maintaining high-purity Ar gas during both filling and exhaust, and keeping the gas pressure at approximately 0.15 MPa. After the holding period, close the gas valve and allow the furnace to cool down to complete the first degreasing step. After removing the sample, place it in a vacuum sintering furnace and raise the temperature to 650℃ at a rate of 5℃ / min, holding it for 120 minutes. After the holding period, allow the furnace to cool down to complete the second degreasing step. Place the block after the second degreasing step in a pressure sintering furnace and evacuate it to 10℃. -3 The temperature was increased to 650℃ in 70 min at a rate of 9.3℃ / min and held for 40 min; then increased to 1100℃ in 50 min at a rate of 9℃ / min and held for 40 min. During this heating process, when the temperature reached 900℃, 0.150 MPa of high-purity Ar was introduced; the temperature was increased to 1350℃ in 50 min at a rate of 5℃ / min and held for 40 min; then increased to 1420℃ in 15 min at a rate of 4.7℃ / min and held for 60 min, while 4.912 MPa of high-purity Ar gas was introduced. After the holding period, the furnace was cooled to room temperature to obtain a high-entropy bonded phase Ti(C,N) based metal ceramic bulk.

[0149] In Comparative Example 3, the high entropy binder content of the cermet was too high. After sintering, the cermet bulk deformed and bent, generating internal stress. The binder formed a continuous network structure between the hard phase grains, and the binder became enriched. The hard phase was over-encapsulated, the grains were severely coarsened, and some agglomeration and porosity appeared. The core-shell structure formed had an excessively thick transition layer (greater than 0.5 μm) and no core. The average size was 5.02 ± 0.36 μm. These factors led to its low strength, fracture toughness and relative density.

[0150] The parameters of the metal ceramics prepared under the above preparation process conditions are shown in Table 11.

[0151] Table 11 shows the mechanical properties and relative density of the cermets prepared using Comparative Example 3.

[0152]

[0153] It is evident that the preparation process parameters and sintering parameters of high-entropy alloys and high-entropy ceramic powders have a relatively large impact on mechanical properties. When the sintering temperature and holding time in the sintering stage are properly matched, the solid-phase and liquid-phase sintering processes in the above stages can be carried out reasonably and fully to prepare high-entropy metallic ceramics with superior comprehensive mechanical properties.

[0154] The high-entropy alloy Ti(C,N) based cermet material provided by this invention has a uniformly distributed core-ring structure and a moderately thick ring phase transition layer that effectively inhibits the growth of Ti(C,N) grains, achieving fine grain strengthening and solid solution strengthening. It has good bending strength, fracture toughness, high hardness and high density, and can be used for high-speed cutting, finishing and semi-finishing under complex conditions.

Claims

1. A method for preparing a high-entropy Ti(C,N)-based cermet material, characterized in that, Includes the following steps: (1) Using Fe, Mn, Co, and Cr elemental metal powders as raw materials, they are mixed and ball-milled to prepare high-entropy alloy powder; the mass percentages of the Fe, Mn, Co, and Cr elemental metal powders are Fe: 48.32~52.32wt%, Mn: 27.70~31.70wt%, Co: 8.62~12.62wt%, and Cr: 7.37~11.37wt%; the entire operation of step (1) is carried out in a circulating purification glove box filled with nitrogen, where the water content is <0.1ppm, the oxygen content is <0.1ppm, and the nitrogen filling pressure is 1.001atm~1.005atm; (2) In the mixed powder composed of the high-entropy alloy powder, Ti(C,N) powder, and secondary carbide powder, a forming agent and anhydrous ethanol are added sequentially, and wet milling is performed to obtain a mixed slurry; the mass percentage of the mixed powder is 100wt%, of which the high-entropy alloy powder accounts for 10~20wt%, and the secondary carbide powder accounts for 10~20wt%. The powder accounts for 15-30 wt%, with the remainder being Ti(C,N) powder; the secondary carbide powder includes Mo2C, Cr3C2, VC and WC powders, with a mass ratio of 2-3:1.5-3.5:0.5-3.5:12-20; the molding agent is paraffin wax, with a mass of 3-4 wt% of the mass of the mixed powder; (3) the block material obtained after drying the mixed slurry is ground, sieved, and pressed into a block; (4) the block is degreased and sintered to obtain High-entropy bonded phase Ti(C,N)-based cermet material; the degreasing process is as follows: the block is placed in a degreasing furnace, evacuated to negative pressure, and then filled with argon gas. After the gas pressure in the degreasing furnace cavity reaches 0.1~0.2MPa, the exhaust valve is opened, and the temperature is raised to 550~650℃ and held for 3~5 hours for the first degreasing. Then, it is cooled with the furnace, maintaining a balance between the intake and exhaust gas during the process, and stabilizing the gas pressure at 0.1~0.2MPa. After the block is cooled to room temperature with the furnace, it is placed in a vacuum sintering furnace and evacuated to 10℃. -3 ~10 -2 After Pa, the temperature is raised to 550~650℃ and held for 1.5~2.5h for a second degreasing; the sintering is high-temperature gas pressure sintering, including the following stages: First stage: vacuuming to 10 -3 ~10 -2 The process is as follows: Stage 1: Heat to 550-650℃ at a rate of 8-10℃ / min and hold for 40-60 min; Stage 2: Heat to 1100-1200℃ at a rate of 7-9℃ / min and hold for 40-60 min. During this stage, when the temperature reaches 850-900℃, start introducing 0.1-0.15 MPa of argon gas; Stage 3: Heat to 1300-1350℃ at a rate of 4-6℃ / min and hold for 30-40 min; Stage 4: Heat to 1400-1420℃ at a rate of 4-6℃ / min, introduce 4-5 MPa of argon gas, and hold for 60-70 min; Stage 5: After the holding period, cool the furnace to room temperature.

2. The preparation method according to claim 1, characterized in that, The ball milling is an intermittent high-energy ball milling process, which is dry grinding. The grinding balls are WC-Co cemented carbide balls, with 25% of the grinding balls having a diameter of 2-3 mm, 50% having a diameter of 4-5 mm, and 25% having a diameter of 6-8 mm. The ball-to-material ratio is 10-15:1, the ball milling speed is 350-450 rpm, and the ball milling time is 60-90 hours, with a 5-10 minute interval between each 1-2 hour ball milling session.

3. The preparation method according to claim 1, characterized in that, In step (2), the mass of the anhydrous ethanol is 1.5 to 2 times the mass of the mixed powder; wet grinding for 8 to 10 hours, with a ball-to-powder ratio of 10:1 to 15:

1.

4. The preparation method according to claim 1, characterized in that, In step (3), the drying is vacuum drying with a vacuum degree of 0.1~20kPa and a drying temperature of 90~100℃; the sieving is done with a 100~150 mesh standard sieve; and the pressing pressure is 230~250MPa.

5. A high-entropy Ti(C,N)-based cermet material obtained by the preparation method according to any one of claims 1 to 4, characterized in that, The binder phase is Fe. 50 Mn 30 Co 10 Cr 10 A high-entropy alloy, wherein the hard phase is Ti(C,N) cermet, and the binder phase is uniformly dispersed between the particles of the hard phase.

6. The high-entropy bonded phase Ti(C,N)-based cermet material according to claim 5, characterized in that, The microstructure of the high-entropy bonded phase Ti(C,N)-based cermet material has a uniformly distributed spherical core-shell structure and a ring-phase transition layer, wherein the average size of the spherical core-shell structure is 0.5~1.5μm and the average thickness of the ring-phase transition layer is 0.2~0.5μm.

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