A (ti, w)c-alcrconimom high-entropy cermet material, a preparation method and application thereof
By employing a two-step wet-dry composite ball milling process and spark plasma coupled high-frequency induction sintering, the problems of agglomeration and cold welding during the ball milling process of (Ti,W)C-AlCrCoNiMo were solved, resulting in the preparation of high-performance high-entropy cermet materials that improved the flexural strength, hardness, and fracture toughness of the materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- QILU UNIVERSITY OF TECHNOLOGY (SHANDONG ACADEMY OF SCIENCES)
- Filing Date
- 2026-02-14
- Publication Date
- 2026-07-31
AI Technical Summary
Existing technologies have not yet provided a systematic way to avoid and eliminate the problems of agglomeration and cold welding during the ball milling of (Ti,W)C-AlCrCoNiMo without introducing impurities. This leads to selective segregation of Cr elements, reduces interfacial strength and corrosion resistance, and affects the performance of high-entropy cermets.
A two-step wet-dry composite ball milling process is adopted. First, the powder is refined and dispersed by high-energy ball milling, followed by a short-time low-energy ball milling. Combined with high-frequency induction sintering by spark plasma coupling, a more uniform pre-alloyed powder is prepared.
It improves the flexural strength, hardness, and fracture toughness of high-entropy cermet materials, reduces the sintering temperature, and enhances their overall mechanical properties.
Smart Images
Figure CN121896517B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of metal ceramic materials technology, specifically relating to a (Ti,W)C-AlCrCoNiMo high-entropy metal ceramic material, its preparation method, and its application. Background Technology
[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.
[0003] The application of ceramic materials (such as alumina) in key components such as guide rails, cutting tools, and molds is relatively mature, but the performance advantages of cermet materials have not yet been fully realized. In recent years, based on the concept of preparing high-entropy cermets by toughening cermets with high-entropy alloys, (Ti,W)C high-entropy cermets prepared by combining the (Ti,W)C hard phase with the high-entropy alloy (HEA) binder phase have become a research hotspot for next-generation high-performance tooling materials.
[0004] In the preparation of (Ti,W)C high-entropy cermets, the bonding and dispersion of the (Ti,W)C hard phase and the high-entropy alloy binder phase are key factors limiting their performance improvement. Especially in the (Ti,W)C-AlCrCoNiMo high-entropy cermet material system, traditional ball milling methods lead to significant selective segregation of Cr, while Al, Co, Ni, Mo, and (Ti,W)C are relatively dispersed. On the one hand, Cr-rich regions induce Cr... 23 The precipitation of the brittle C6 phase reduces interfacial strength; on the other hand, local Cr depletion disrupts the multi-principal-element high-entropy effect of the HEA binder phase, leading to decreased corrosion resistance and thermal stability; furthermore, the hard phase is encapsulated by a Cr-rich metal layer, causing load transfer failure. Selective segregation of metal elements also occurs. Therefore, optimizing the ball milling process is a key means to solve the problem of mechanical alloying and uniform mixing of (Ti,W)C and HEA powders.
[0005] Currently, optimized ball milling methods include the addition of process control agents (PCA), optimization of ball milling parameters, and post-milling sieving. However, for the (Ti,W)C-AlCrCoNiMo system, the addition of conventional PCA has limited effect on cold welding and agglomeration inhibition; simple optimization of ball milling parameters is difficult to balance mixing efficiency and agglomeration inhibition; and sieving can only remove macroscopic agglomerates.
[0006] Therefore, the existing technology has not yet provided a solution for systematically avoiding and eliminating agglomeration and cold welding during the ball milling process of (Ti,W)C-AlCrCoNiMo without introducing impurities. Summary of the Invention
[0007] To address the shortcomings of existing technologies, the purpose of this invention is to provide a (Ti,W)C-AlCrCoNiMo high-entropy cermet material, its preparation method, and its applications. This invention provides a cermet material with (Ti,W)C ceramic as the matrix, Al, Cr, Co, Ni, and Mo added as high-entropy alloy binder phases, processed by a two-step wet-dry composite ball milling process, and then sintered by high-frequency induction sintering via spark plasma coupling.
[0008] This invention proposes a two-step wet-dry composite ball milling process for preparing (Ti,W)C-AlCrCoNiMo cermet materials. The first stage is wet high-energy ball milling, which mainly uses the point contact between the high-hardness milling balls and the hard phase (Ti,W)C ceramic particles to generate shearing and micro-ploughing effects on the powder, thereby refining, breaking down, and uniformly dispersing the powder. The second stage involves dry ball milling of the powder from the first stage, using short-time low-energy ball milling. This not only solves the problem of agglomeration and obtains ideal pre-alloyed powder, but also avoids agglomerates with relatively large particle sizes in the powder, resulting in a more uniform composition of the prepared powder particles.
[0009] To achieve the above objectives, the technical solution of the present invention is as follows:
[0010] In a first aspect, the present invention provides a (Ti,W)C-AlCrCoNiMo high-entropy cermet material, with (Ti,W)C as the matrix and Al, Cr, Co, Ni, and Mo as the binder phase HEA. The volume percentage of each component is as follows: (Ti,W)C 80-95%, HEA 5-20%, wherein the volume ratio of the five metals in the binder phase HEA is (0.9~1.1):(0.9~1.1):(0.9~1.1):(0.9~1.1):(0.9~1.1).
[0011] Secondly, this invention provides a method for preparing the above-mentioned (Ti,W)C-AlCrCoNiMo high-entropy cermet material, which employs a two-step wet-dry composite ball milling process, including the following steps: After mixing polyethylene glycol-anhydrous ethanol dispersion with (Ti,W)C, Al, Cr, Co, Ni, and Mo powders mixed in volume ratio, the mixture is subjected to a first-stage wet ball milling process (wet milling). The slurry obtained from the ball milling process is then dried, ground, and sieved. The sieved mixture is then subjected to a second stage of dry ball milling (dry milling). The ball-milled mixed powder is placed in a graphite mold and subjected to high-frequency induction sintering via discharge plasma coupling under a vacuum atmosphere to obtain the final product.
[0012] Thirdly, the present invention provides the application of the above-mentioned (Ti,W)C-AlCrCoNiMo high-entropy cermet material in the preparation of ceramic cutting tools.
[0013] Fourthly, the present invention provides a metal-ceramic cutting tool comprising the above-mentioned (Ti,W)C-AlCrCoNiMo high-entropy metal-ceramic material.
[0014] One or more of the above technical solutions have the following advantages or beneficial effects: (1) The (Ti,W)C-AlCrCoNiMo high-entropy cermet material prepared by the present invention based on a two-step wet-dry composite ball milling process can solve the segregation problem and obtain an ideal pre-alloyed powder with more uniform composition and better dispersibility by using Al, Cr, Co, Ni and Mo as high-entropy alloy binder phases and (Ti,W)C hard phase powder as a two-step wet-dry composite ball milling process.
[0015] (2) The composite powder after being processed by the optimized ball milling method is subjected to high-frequency induction sintering by discharge plasma coupling. At a sintering temperature of 1300℃, a high-entropy metal ceramic material with high bending strength, high hardness and excellent fracture toughness can be obtained. Compared with the high-entropy metal ceramic material (Ti,W)C-AlCrCoNiMo) prepared by the traditional process (only one high-energy wet milling, sintering temperature of 1400℃), the sintering activity is improved, the sintering temperature is reduced, and the comprehensive mechanical properties are significantly improved.
[0016] (3) The (Ti,W)C-AlCrCoNiMo high-entropy cermet material samples prepared by the two-step wet-dry composite ball milling process of this invention were cut and processed, and the mechanical properties were measured as follows: bending strength 885~1366MPa, fracture toughness 5.76~7.4MPa. m 1 / 2 Its hardness is 16.59~19.34 GPa. Attached Figure Description
[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.
[0018] Figure 1 The image shows the morphology of (Ti,W)C-AlCrCoNiMo high-entropy cermet powder prepared by conventional ball milling process (wet milling and drying treatment only, no dry milling); where (a) shows the soft agglomeration phenomenon in the powder and (b) shows the cold welding phenomenon in the powder. Figure 2The images show the SEM and EDS images of (Ti,W)C-AlCrCoNiMo high-entropy cermet powder prepared by conventional ball milling process (wet milling and drying only, no dry milling) in Comparative Example 1; the white dashed lines refer to the test areas. Figure 3 The microstructure of (Ti,W)C-AlCrCoNiMo high-entropy cermet powder after different processes in Example 1 is compared; (a) is the powder obtained after high-energy wet ball milling and drying without grinding and sieving, (b) is the powder obtained after high-energy wet ball milling and drying with grinding and sieving, and (c) is the two-step wet-dry composite ball milling process. Figure 4 The image shows an electron microscope and elemental analysis of the (Ti,W)C-AlCrCoNiMo high-entropy cermet material prepared by a two-step wet-dry composite ball milling process in Example 1; the white dashed line indicates the test area. Detailed Implementation
[0019] This invention provides a (Ti,W)C-AlCrCoNiMo high-entropy cermet material, which uses (Ti,W)C as the matrix and adds Al, Cr, Co, Ni, and Mo as binder phases. It is prepared by a two-step wet-dry composite ball milling process followed by spark plasma coupling high-frequency induction sintering. The volume percentage of each component is: (Ti,W)C 80-95%, HEA 5-20%, with a volume ratio of the five metals of 1:1:1:1:1. The preparation method involves first mixing (Ti,W)C, Al, Cr, Co, Ni, and Mo in the specified volume ratio, then obtaining a composite powder through a two-step wet-dry composite ball milling process, followed by spark plasma coupling high-frequency induction sintering. This method, based on the two-step wet-dry composite ball milling process, solves the segregation problem, obtains an ideal pre-alloyed powder with more uniform composition and better dispersibility, and improves the overall performance of the sintered high-entropy cermet material. The obtained (Ti,W)C-AlCrCoNiMo high-entropy cermet material retains the advantages of ceramics, such as high hardness, wear resistance, high temperature resistance and good chemical stability, while combining the high ductility and toughness of metals. It can be used to manufacture high-precision CNC machine tool guideways and other wear-resistant and corrosion-resistant parts.
[0020] In a typical embodiment, the present invention provides a (Ti,W)C-AlCrCoNiMo high-entropy cermet material, with (Ti,W)C as the matrix and Al, Cr, Co, Ni, and Mo as the binder phase HEA. The volume percentage of each component is: (Ti,W)C 80~95%, HEA 5~20%, wherein the volume ratio of the five metals in the binder phase HEA is (0.9~1.1):(0.9~1.1):(0.9~1.1):(0.9~1.1):(0.9~1.1), preferably 1:1:1:1:1:1.
[0021] Preferably, the volume percentage of each component is: (Ti,W)C 89.5~90.5%, Al 1.5~2.5%, Cr 1.5~2.5%, Co 1.5~2.5%, Ni 1.5~2.5%, Mo 1.5~2.5%. Most preferably, the volume percentage of each component is: (Ti,W)C 90%, Al 2%, Cr 2%, Co 2%, Ni 2%, Mo 2%.
[0022] The (Ti,W)C-AlCrCoNiMo high-entropy cermet material is formed by a two-step wet-dry composite ball milling process followed by high-frequency induction sintering via spark plasma coupling.
[0023] In a typical embodiment, the present invention provides a method for preparing the above-mentioned (Ti,W)C-AlCrCoNiMo high-entropy cermet material, which employs a two-step wet-dry composite ball milling process, including the following steps: After mixing polyethylene glycol-anhydrous ethanol dispersion with (Ti,W)C, Al, Cr, Co, Ni, and Mo powders mixed in volume ratio, the mixture is subjected to a first-stage wet ball milling process. The slurry obtained from the ball milling process is then dried, ground, and sieved. The sieved mixture is then subjected to a second stage of dry ball milling. The ball-milled mixed powder is placed in a graphite mold and subjected to high-frequency induction sintering via discharge plasma coupling under a vacuum atmosphere to obtain the final product.
[0024] In the polyethylene glycol-anhydrous ethanol dispersion, the amount of polyethylene glycol dispersed is 2~4 g / L, and its mass is 0.09%~1.1% of the sum of the masses of (Ti,W)C powder and HEA powder.
[0025] The average particle size of the (Ti,W)C powder is 1~3μm, preferably 1~1.5μm.
[0026] The average particle size of Al powder, Cr powder, Co powder, Ni powder, and Mo powder is 1~3μm, preferably 1~1.5μm.
[0027] In the first stage of the two-step wet-dry composite ball milling process, the total amount of powder raw material to the weight ratio of grinding balls is 1:(10~20), preferably 1:10, and the ball milling is carried out for 24-48 hours under a protective atmosphere.
[0028] In the first stage of the two-step wet-dry composite ball milling process, the protective atmosphere includes nitrogen. The grinding balls used are cemented carbide grinding balls, specifically a mixture of 5mm and 10mm diameter cemented carbide grinding balls. The mass ratio of the 5mm to 10mm diameter cemented carbide balls is (1~2):(1~5), and the ball-to-material mass ratio is (10~20):1. The ball milling process described in this invention is a high-energy ball milling process, employing a stirred high-energy ball mill. Inert gas protection and circulating water cooling are used during ball milling, with a rotation speed of 300~600 rpm, preferably 400 rpm.
[0029] The drying process employs vacuum drying technology, with a vacuum drying temperature of 100~120℃ and a vacuum drying time of 24~48h, preferably 24h.
[0030] Since the powder may clump together into plates or flakes after drying, it needs to be ground in a mortar before sieving. However, during the preparation process of this invention, it was found that even after grinding, agglomeration still exists.
[0031] The sieve mesh should be 100~200 mesh, preferably 100 mesh.
[0032] In the second stage of the two-step wet-dry composite ball milling process, the ball milling time is controlled at 1-2 hours, the ball-to-material ratio is (2-8):1, preferably 5:1, and the rotation speed is 100-300 rpm, preferably 200 rpm. The second stage dry milling process is solvent-free, conducted under a protective gas atmosphere, including an inert gas. The powder after the second stage dry milling is directly used for molding and sintering. Compared to the first stage wet milling process, the ball-to-material ratio and rotation speed are changed in the second stage dry milling process. The purpose of this change is to reduce the ball milling intensity and avoid cold welding and agglomeration during the dry milling process.
[0033] The conditions for spark plasma coupling high-frequency induction sintering are: sintering temperature of 1200~1400℃, preferably 1250~1350℃, and sintering pressure of 30-40MPa. The heating process employs a multi-stage heating method: preheating to 560-580℃ and then heating to 600℃ within 0.5-1.5 min; heating to 900℃ at a rate of 90-110℃ / min; heating to 1200℃ at a rate of 70-80℃ / min; and heating to the target temperature at a rate of 40-60℃ / min, with a holding time of 5-15 min (preferably 8-12 min). Most preferably, the heating process is as follows: preheating to 570℃ and then heating to 600℃ within 1 min; heating to 900℃ at a rate of 100℃ / min; heating to 1200℃ at a rate of 75℃ / min; and heating to the target temperature at a rate of 50℃ / min, with a holding time of 10 min.
[0034] During the heating process, a single-stage heating method cannot be used because it is not conducive to controlling grain growth and can easily lead to insufficient or excessive sintering. Multi-stage heating is more conducive to the sintering and forming of materials. This design is based on the characteristics of the SPS sintering furnace and the inventor's long-term experience in sintering tungsten carbide titanium material systems. The initial high heating rate promotes grain growth and rearrangement, the rate is reduced in the middle stage to promote densification, and the heating rate is reduced in the later stage to inhibit abnormal grain growth.
[0035] In one typical embodiment, the present invention provides the application of the above-mentioned (Ti,W)C-AlCrCoNiMo high-entropy cermet material in the preparation of ceramic cutting tools.
[0036] In one typical embodiment, the present invention provides a cermet cutting tool comprising the above-mentioned (Ti,W)C-AlCrCoNiMo high-entropy cermet material.
[0037] In this invention, unless otherwise specified, all other test materials and instruments are conventional test materials in the field and can be purchased through commercial channels.
[0038] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.
[0039] Example 1 In the examples, the average particle size of (Ti,W)C powder was 1~3μm, and the average particle size of Al, Cr, Co, Ni, and Mo powders was 1~3μm, all of which were commercially available products.
[0040] The volume percentage of each component in the (Ti,W)C-AlCrCoNiMo high-entropy cermet material is as follows: (Ti,W)C - 90%, Al - 2%, Cr - 2%, Co - 2%, Ni - 2%, Mo - 2%.
[0041] The preparation method of the (Ti,W)C-AlCrCoNiMo high-entropy cermet material includes the following steps: (1) Place anhydrous ethanol in a beaker, weigh and add polyethylene glycol, place the beaker in a water bath, and stir magnetically at 55℃ for 10 min until the polyethylene glycol is completely dissolved. Cool to room temperature to obtain a polyethylene glycol-anhydrous ethanol dispersion with a dispersion amount of 2 g / L. Mix the powders of each component according to the volume percentage of (Ti,W)C-90%, Al-2%, Cr-2%, Co-2%, Ni-2%, and Mo-2% to obtain a mixed solution. The mass of polyethylene glycol in the polyethylene glycol-anhydrous ethanol dispersion is 0.09% of the sum of the masses of (Ti,W)C, Al, Cr, Co, Ni, and Mo powders. (2) The prepared mixed solution was placed in a ball mill jar and subjected to the first stage of the two-step wet-dry composite ball milling process, which was a high-energy wet ball milling process. The grinding balls used in the ball milling were cemented carbide grinding balls, which were mixed cemented carbide grinding balls with diameters of 5 mm and 10 mm. The mass ratio of the cemented carbide balls with diameters of 5 mm and 10 mm was 1:1, and the mass ratio of the ball to the material was 10:1. The ball milling was carried out at 400 rpm for 24 hours under a nitrogen protective atmosphere. (3) Dry the ball mill slurry under vacuum at 120°C for 24 hours, grind it in a mortar, pass it through a 200-mesh sieve, and seal it for later use; (4) Before sintering and molding, the sieved mixed powder is subjected to the second stage of dry ball milling in a two-step wet-dry composite ball milling process. The grinding balls used in the ball milling are cemented carbide grinding balls, which are mixed cemented carbide grinding balls with diameters of 5 mm and 10 mm. The mass ratio of the cemented carbide balls with diameters of 5 mm and 10 mm is 1:1, and the mass ratio of the ball to the material is 5:1. The mixed powder is obtained by ball milling at 200 rpm for 1 hour under a nitrogen protective atmosphere. (5) The (Ti,W)C-AlCrCoNiMo high-entropy metal ceramic mixed powder was placed in a graphite mold and subjected to high-frequency induction sintering by discharge plasma coupling under a vacuum atmosphere. The sintering temperature was 1300℃, the sintering pressure was 30MPa, and the heating rate was as follows: preheating to 570℃ and heating to 600℃ within 1min; heating to 900℃ at 100℃ / min; heating to 1200℃ at 75℃ / min; heating to the target temperature at 50℃ / min, and holding for 10min to obtain the (Ti,W)C-AlCrCoNiMo high-entropy metal ceramic material.
[0042] The prepared ceramic material sample was cut and processed, and its mechanical properties were measured as follows: flexural strength 1366 MPa, fracture toughness 7.4 MPa. m 1 / 2 Vickers hardness 18.91 GPa.
[0043] Example 2 In the examples, the average particle size of (Ti,W)C powder was 1~3μm, and the average particle size of Al, Cr, Co, Ni, and Mo powders was 1~3μm, all of which were commercially available products.
[0044] The volume percentage of each component in the (Ti,W)C-AlCrCoNiMo high-entropy cermet material is as follows: (Ti,W)C - 90%, Al - 2%, Cr - 2%, Co - 2%, Ni - 2%, Mo - 2%.
[0045] The preparation method of the (Ti,W)C-AlCrCoNiMo high-entropy cermet material includes the following steps: (1) Place anhydrous ethanol in a beaker, weigh and add polyethylene glycol, place the beaker in a water bath, and stir magnetically at 55℃ for 10 min until the polyethylene glycol is completely dissolved. Cool to room temperature to obtain a polyethylene glycol-anhydrous ethanol dispersion with a dispersion amount of 2 g / L. Mix the powders of each component according to the volume percentage of (Ti,W)C-90%, Al-2%, Cr-2%, Co-2%, Ni-2%, and Mo-2% to obtain a mixed solution. The mass of polyethylene glycol in the polyethylene glycol-anhydrous ethanol dispersion is 0.09% of the sum of the masses of (Ti,W)C, Al, Cr, Co, Ni, and Mo powders. (2) The prepared mixed solution was placed in a ball milling jar and subjected to the first stage of the two-step wet-dry composite ball milling process, which was a high-energy wet ball milling process. The grinding balls used in the ball milling were cemented carbide grinding balls, which were mixed cemented carbide grinding balls with diameters of 5 mm and 10 mm. The mass ratio of the cemented carbide balls with diameters of 5 mm and 10 mm was 1:1, and the mass ratio of the ball to the material was 10:1. The ball milling was carried out at 400 rpm for 48 hours under a nitrogen protective atmosphere. (3) Dry the ball mill slurry under vacuum at 120°C for 24 hours, grind it in a mortar, pass it through a 200-mesh sieve, and seal it for later use; (4) Before sintering and molding, the sieved mixed powder is subjected to the second stage of dry ball milling in a two-step wet-dry composite ball milling process. The grinding balls used in the ball milling are cemented carbide grinding balls, which are mixed cemented carbide grinding balls with diameters of 5 mm and 10 mm. The mass ratio of the cemented carbide balls with diameters of 5 mm and 10 mm is 1:1, and the mass ratio of the ball to the material is 5:1. The mixed powder is obtained by ball milling at 200 rpm for 1 hour under a nitrogen protective atmosphere. (5) The (Ti,W)C-AlCrCoNiMo high-entropy metal ceramic mixed powder was placed in a graphite mold and subjected to high-frequency induction sintering by discharge plasma coupling under a vacuum atmosphere. The sintering temperature was 1300℃, the sintering pressure was 30MPa, and the heating rate was as follows: preheating to 570℃ and then heating to 600℃ within 1min; heating to 900℃ at 100℃ / min; heating to 1200℃ at 75℃ / min; heating to the target temperature at 50℃ / min, and holding for 10min to obtain the (Ti,W)C-AlCrCoNiMo high-entropy metal ceramic material.
[0046] The prepared ceramic material sample was cut and processed, and its mechanical properties were measured as follows: flexural strength 1059 MPa, fracture toughness 6.97 MPa. m 1 / 2 Vickers hardness 18.34 GPa.
[0047] Example 3 In the examples, the average particle size of (Ti,W)C powder was 1~3μm, and the average particle size of Al, Cr, Co, Ni, and Mo powders was 1~3μm, all of which were commercially available products.
[0048] The volume percentage of each component in the (Ti,W)C-AlCrCoNiMo high-entropy cermet material is as follows: (Ti,W)C - 90%, Al - 2%, Cr - 2%, Co - 2%, Ni - 2%, Mo - 2%.
[0049] The preparation method of the (Ti,W)C-AlCrCoNiMo high-entropy cermet material includes the following steps: (1) Place anhydrous ethanol in a beaker, weigh and add polyethylene glycol, place the beaker in a water bath, and stir magnetically at 55℃ for 10 min until the polyethylene glycol is completely dissolved. Cool to room temperature to obtain a polyethylene glycol-anhydrous ethanol dispersion with a dispersion amount of 2 g / L. Mix the powders of each component according to the volume percentage of (Ti,W)C-90%, Al-2%, Cr-2%, Co-2%, Ni-2%, and Mo-2% to obtain a mixed solution. The mass of polyethylene glycol in the polyethylene glycol-anhydrous ethanol dispersion is 0.09% of the sum of the masses of (Ti,W)C, Al, Cr, Co, Ni, and Mo powders. (2) The prepared mixed solution was placed in a ball mill jar and subjected to the first stage of the two-step wet-dry composite ball milling process, which was a high-energy wet ball milling process. The grinding balls used in the ball milling were cemented carbide grinding balls, which were mixed cemented carbide grinding balls with diameters of 5 mm and 10 mm. The mass ratio of the cemented carbide balls with diameters of 5 mm and 10 mm was 1:1, and the mass ratio of the ball to the material was 10:1. The ball milling was carried out at 400 rpm for 24 hours under a nitrogen protective atmosphere. (3) Dry the ball mill slurry under vacuum at 120°C for 24 hours, grind it in a mortar, pass it through a 200-mesh sieve, and seal it for later use; (4) Before sintering and molding, the sieved mixed powder is subjected to the second stage of dry ball milling in a two-step wet-dry composite ball milling process. The grinding balls used in the ball milling are cemented carbide grinding balls, which are mixed cemented carbide grinding balls with diameters of 5 mm and 10 mm. The mass ratio of the cemented carbide balls with diameters of 5 mm and 10 mm is 1:1, and the mass ratio of the ball to the material is 5:1. The mixed powder is obtained by ball milling at 200 rpm for 2 hours under a nitrogen protective atmosphere. (5) The (Ti,W)C-AlCrCoNiMo high-entropy metal ceramic mixed powder was placed in a graphite mold and subjected to high-frequency induction sintering by discharge plasma coupling under a vacuum atmosphere. The sintering temperature was 1300℃, the sintering pressure was 30MPa, and the heating rate was as follows: preheating to 570℃ and heating to 600℃ within 1min; heating to 900℃ at 100℃ / min; heating to 1200℃ at 75℃ / min; heating to the target temperature at 50℃ / min, and holding for 10min to obtain the (Ti,W)C-AlCrCoNiMo high-entropy metal ceramic material.
[0050] The prepared ceramic material sample was cut and processed, and its mechanical properties were measured as follows: flexural strength 993.7 MPa, fracture toughness 5.8 MPa. m 1 / 2 Vickers hardness 18.35 GPa.
[0051] Example 4 In the examples, the average particle size of (Ti,W)C powder was 1~3μm, and the average particle size of Al, Cr, Co, Ni, and Mo powders was 1~3μm, all of which were commercially available products.
[0052] The volume percentage of each component in the (Ti,W)C-AlCrCoNiMo high-entropy cermet material is as follows: (Ti,W)C - 90%, Al - 2%, Cr - 2%, Co - 2%, Ni - 2%, Mo - 2%.
[0053] The preparation method of the (Ti,W)C-AlCrCoNiMo high-entropy cermet material includes the following steps: (1) Place anhydrous ethanol in a beaker, weigh and add polyethylene glycol, place the beaker in a water bath, and stir magnetically at 55℃ for 10 min until the polyethylene glycol is completely dissolved. Cool to room temperature to obtain a polyethylene glycol-anhydrous ethanol dispersion with a dispersion amount of 2 g / L. Mix the powders of each component according to the volume percentage of (Ti,W)C-90%, Al-2%, Cr-2%, Co-2%, Ni-2%, and Mo-2% to obtain a mixed solution. The mass of polyethylene glycol in the polyethylene glycol-anhydrous ethanol dispersion is 0.09% of the sum of the masses of (Ti,W)C, Al, Cr, Co, Ni, and Mo powders. (2) The prepared mixed solution was placed in a ball mill jar and subjected to the first stage of the two-step wet-dry composite ball milling process, which was a high-energy wet ball milling process. The grinding balls used in the ball milling were cemented carbide grinding balls, which were mixed cemented carbide grinding balls with diameters of 5 mm and 10 mm. The mass ratio of the cemented carbide balls with diameters of 5 mm and 10 mm was 1:1, and the mass ratio of the ball to the material was 10:1. The ball milling was carried out at 400 rpm for 24 hours under a nitrogen protective atmosphere. (3) Dry the ball mill slurry under vacuum at 120°C for 24 hours, grind it in a mortar, pass it through a 200-mesh sieve, and seal it for later use; (4) Before sintering and molding, the sieved mixed powder is subjected to the second stage of dry ball milling in a two-step wet-dry composite ball milling process. The grinding balls used in the ball milling are cemented carbide grinding balls, which are mixed cemented carbide grinding balls with diameters of 5 mm and 10 mm. The mass ratio of the cemented carbide balls with diameters of 5 mm and 10 mm is 1:1, and the mass ratio of the ball to the material is 5:1. The mixed powder is obtained by ball milling at 200 rpm for 1 hour under a nitrogen protective atmosphere. (5) The (Ti,W)C-AlCrCoNiMo high-entropy metal ceramic mixed powder was placed in a graphite mold and subjected to high-frequency induction sintering by discharge plasma coupling under a vacuum atmosphere. The sintering temperature was 1400℃, the sintering pressure was 30MPa, and the heating rate was as follows: preheating to 570℃ and then heating to 600℃ within 1min; heating to 900℃ at 100℃ / min; heating to 1200℃ at 75℃ / min; heating to the target temperature at 50℃ / min, and holding for 10min to obtain the (Ti,W)C-AlCrCoNiMo high-entropy metal ceramic material.
[0054] The prepared ceramic material sample was cut and processed, and its mechanical properties were measured as follows: flexural strength 885 MPa, fracture toughness 5.76 MPa. m 1 / 2 Vickers hardness 19.34 GPa.
[0055] Example 5 In the examples, the average particle size of (Ti,W)C powder was 1~3μm, and the average particle size of Al, Cr, Co, Ni, and Mo powders was 1~3μm, all of which were commercially available products.
[0056] The volume percentage of each component in the (Ti,W)C-AlCrCoNiMo high-entropy cermet material is as follows: (Ti,W)C - 90%, Al - 2%, Cr - 2%, Co - 2%, Ni - 2%, Mo - 2%.
[0057] The preparation method of the (Ti,W)C-AlCrCoNiMo high-entropy cermet material includes the following steps: (1) Place anhydrous ethanol in a beaker, weigh and add polyethylene glycol, place the beaker in a water bath, and stir magnetically at 55℃ for 10 min until the polyethylene glycol is completely dissolved. Cool to room temperature to obtain a polyethylene glycol-anhydrous ethanol dispersion with a dispersion amount of 2 g / L. Mix the powders of each component according to the volume percentage of (Ti,W)C-90%, Al-2%, Cr-2%, Co-2%, Ni-2%, and Mo-2% to obtain a mixed solution. The mass of polyethylene glycol in the polyethylene glycol-anhydrous ethanol dispersion is 0.09% of the sum of the masses of (Ti,W)C, Al, Cr, Co, Ni, and Mo powders. (2) The prepared mixed solution was placed in a ball mill jar and subjected to the first stage of the two-step wet-dry composite ball milling process, which was a high-energy wet ball milling process. The grinding balls used in the ball milling were cemented carbide grinding balls, which were mixed cemented carbide grinding balls with diameters of 5 mm and 10 mm. The mass ratio of the cemented carbide balls with diameters of 5 mm and 10 mm was 1:1, and the mass ratio of the ball to the material was 10:1. The ball milling was carried out at 400 rpm for 24 hours under a nitrogen protective atmosphere. (3) Dry the ball mill slurry under vacuum at 120°C for 24 hours, grind it in a mortar, pass it through a 200-mesh sieve, and seal it for later use; (4) Before sintering and molding, the sieved mixed powder is subjected to the second stage of dry ball milling in a two-step wet-dry composite ball milling process. The grinding balls used in the ball milling are cemented carbide grinding balls, which are mixed cemented carbide grinding balls with diameters of 5 mm and 10 mm. The mass ratio of the cemented carbide balls with diameters of 5 mm and 10 mm is 1:1, and the mass ratio of the ball to the material is 5:1. The mixed powder is obtained by ball milling at 200 rpm for 1 hour under a nitrogen protective atmosphere. (5) The (Ti,W)C-AlCrCoNiMo high-entropy metal ceramic mixed powder was placed in a graphite mold and subjected to high-frequency induction sintering by discharge plasma coupling under a vacuum atmosphere. The sintering temperature was 1200℃, the sintering pressure was 30MPa, and the heating rate was as follows: preheating to 570℃ and heating to 600℃ within 1min; heating to 900℃ at 100℃ / min; heating to 1200℃ at 75℃ / min; heating to the target temperature at 50℃ / min, and holding for 10min to obtain the (Ti,W)C-AlCrCoNiMo high-entropy metal ceramic material.
[0058] The prepared ceramic material sample was cut and processed, and its mechanical properties were measured as follows: flexural strength 964 MPa, fracture toughness 7.3 MPa. m 1 / 2 Vickers hardness 18.31 GPa.
[0059] Comparative Example 1 Unlike Example 1, the second stage of the two-step wet-dry composite ball milling process is not performed in step (4). The other preparations are the same as in Example 1. The obtained ceramic material sample is cut and processed, and its mechanical properties are measured as follows: bending strength 1246 MPa, fracture toughness 7.1 MPa. m 1 / 2 Vickers hardness 18.4 GPa.
[0060] Comparative Example 2 Unlike Example 1, the ball-to-material mass ratio in step (4) was 10:1. The mixed powder was obtained by ball milling at 300 rpm for 3 hours under a nitrogen protective atmosphere. Other preparation methods were the same as in Example 1. The obtained ceramic material sample was cut and processed, and its mechanical properties were measured as follows: flexural strength 1050 MPa, fracture toughness 6.52 MPa. m 1 / 2 Vickers hardness 17.8 GPa.
[0061] Comparative Example 3 Unlike Example 1, the wet grinding in step (2) and the dry grinding in step (4) were reversed, i.e., dry grinding was performed first, followed by wet grinding. The other preparation methods were the same as in Example 1. The obtained ceramic material sample was cut and processed, and its mechanical properties were measured as follows: flexural strength 912 MPa, fracture toughness 6.41 MPa. m 1 / 2 Vickers hardness 19.21 GPa.
[0062] Comparative Example 4 Unlike Example 1, the volume percentage content in step (1) was: (Ti,W)C - 94%, Co - 2%, Ni - 2%, Mo - 2%. Other preparation methods were the same as in Example 1. The obtained ceramic material sample was cut and processed, and its mechanical properties were measured as follows: flexural strength 1105 MPa, fracture toughness 6.7 MPa. m 1 / 2 Vickers hardness 16.7 GPa.
[0063] Comparative Example 5 Unlike Example 1, the volume percentage content in step (1) is: (Ti,W)C-85%, Al-3%, Cr-3%, Co-3%, Ni-3%, Mo-3%. Other preparation methods are the same as in Example 1. The obtained ceramic material sample is cut and processed, and its mechanical properties are measured as follows: flexural strength 1185MPa, fracture toughness 7MPa. m 1 / 2 Vickers hardness 16.59 GPa.
[0064] Figure 1 The (Ti,W)C-AlCrCoNiMo high-entropy cermet powder prepared in Comparative Example 1 by ordinary ball milling process (wet milling and drying treatment only, without dry milling) showed obvious agglomeration and cold welding phenomena.
[0065] Figure 2 In Comparative Example 1, a cold-welded metallurgical bonding region with a relatively large particle size was observed in the (Ti,W)C-AlCrCoNiMo high-entropy cermet powder prepared by ordinary ball milling. EDS analysis showed that the Cr element in this cold-welded metallurgical bonding region exhibited significant selective segregation.
[0066] It should be noted that, Figure 1 and Figure 2 The images shown are characterization diagrams of the powder obtained after ordinary ball milling treatment in Comparative Example 1 before sintering and forming.
[0067] Figure 3 This is a comparison of the microstructures of (Ti,W)C-AlCrCoNiMo high-entropy cermet powders after different processing steps in Example 1. Figure 3 (a) shows the powder obtained after high-energy wet ball milling and drying, but without grinding or sieving. Clearly, the powder obtained only after wet milling exhibits significant agglomeration. Figure 3 (b) in the image represents the powder obtained after high-energy wet ball milling and drying, followed by grinding and sieving. Clearly, although compared to... Figure 3 In (a), grinding and sieving were added, but agglomeration and cold welding problems still exist. Figure 3(c) in the diagram represents a two-step wet-dry composite ball milling process. After wet milling, drying, grinding, sieving, and dry milling are performed to obtain a relatively uniform powder. Therefore, Figure 3 This indicates that grinding and sieving can only remove macroscopic agglomerates and cannot completely eliminate agglomeration and cold welding. The powder processed by the two-step wet-dry composite ball milling process is relatively uniform.
[0068] Figure 4 This is an electron microscope and elemental analysis diagram of the (Ti,W)C-AlCrCoNiMo high-entropy cermet material prepared by a two-step wet-dry composite ball milling process in Example 1. The diagram clearly shows that the high-entropy alloying elements exist at the grain boundaries (i.e., the interfaces between grains), forming an intergranular mixed structure.
[0069] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A (Ti,W)C-AlCrCoNiMo high-entropy cermet material, characterized in that, Using (Ti,W)C as the matrix and Al, Cr, Co, Ni, and Mo as the binder phase HEA, the volume percentage of each component is: (Ti,W)C 80~95%, HEA 5~20%, wherein the volume ratio of the five metals in the binder phase HEA is (0.9~1.1):(0.9~1.1):(0.9~1.1):(0.9~1.1):(0.9~1.1). The preparation method of the (Ti,W)C-AlCrCoNiMo high-entropy cermet material adopts a two-step wet-dry composite ball milling process, including the following steps: After mixing polyethylene glycol-anhydrous ethanol dispersion with (Ti,W)C and HEA powders mixed in volume ratio, the first stage of wet ball milling was carried out. The slurry obtained from the ball milling was dried, ground, and sieved. The mixture after sieving is subjected to a second stage of dry ball milling. The ball-milled powder is then placed in a graphite mold and subjected to high-frequency induction sintering via discharge plasma coupling under a vacuum atmosphere to obtain the final product.
2. A method for preparing the (Ti,W)C-AlCrCoNiMo high-entropy cermet material according to claim 1, characterized in that, A two-step wet-dry composite ball milling process was adopted, including the following steps: After mixing polyethylene glycol-anhydrous ethanol dispersion with (Ti,W)C and HEA powders mixed in volume ratio, the first stage of wet ball milling was carried out. The slurry obtained from the ball milling was dried, ground, and sieved. The mixture after sieving is subjected to a second stage of dry ball milling. The ball-milled powder is then placed in a graphite mold and subjected to high-frequency induction sintering via discharge plasma coupling under a vacuum atmosphere to obtain the final product.
3. The preparation method according to claim 2, characterized in that, In the polyethylene glycol-anhydrous ethanol dispersion, the dispersion amount of polyethylene glycol is 2~4 g / L, and its mass is 0.09%~1.1% of the sum of the masses of (Ti,W)C powder and HEA powder.
4. The preparation method according to claim 2, characterized in that, The average particle size of (Ti,W)C powder is 1~3μm; In HEA powder, the average particle size of Al powder, Cr powder, Co powder, Ni powder, and Mo powder is 1~3μm.
5. The preparation method according to claim 2, characterized in that, In the first stage of wet ball milling, the total amount of powder raw material to the weight ratio of grinding balls is 1:(10~20), and the ball milling is carried out for 24~48 hours under a protective atmosphere. The grinding balls used in the ball mill are cemented carbide grinding balls, which are a mixture of cemented carbide grinding balls with diameters of 5 mm and 10 mm. The mass ratio of the cemented carbide grinding balls with diameters of 5 mm and 10 mm is (1~2):(1~5). The ball mill rotates at 300-600 rpm.
6. The preparation method according to claim 2, characterized in that, The drying process adopts vacuum drying technology, with a vacuum drying temperature of 100~120℃ and a vacuum drying time of 24~48h. The sieve is 100~200 mesh.
7. The preparation method according to claim 2, characterized in that, In the second stage of dry ball milling, the milling time is controlled at 1~2 hours, the ball-to-material ratio is (2~8):1, and the rotation speed is 100~300 rpm.
8. The preparation method according to claim 2, characterized in that, The conditions for spark plasma coupling high-frequency induction sintering are: sintering temperature 1200~1400℃, sintering pressure 30~40MPa; The heating process employs a multi-stage heating method: preheating to 560~580 ℃, then heating to 600 ℃ within 0.5~1.5 min; heating to 900 ℃ at 90~110 ℃ / min; heating to 1200 ℃ at 70~80 ℃ / min; and heating to the target temperature at 40~60 ℃ / min, with a holding time of 5~15 min.
9. The application of the (Ti,W)C-AlCrCoNiMo high-entropy cermet material of claim 1 or the (Ti,W)C-AlCrCoNiMo high-entropy cermet material prepared by the preparation method of any one of claims 2 to 8 in the preparation of ceramic cutting tools.
10. A metal-ceramic cutting tool, characterized in that, This includes the (Ti,W)C-AlCrCoNiMo high-entropy cermet material as described in claim 1 or the (Ti,W)C-AlCrCoNiMo high-entropy cermet material prepared by the preparation method described in any one of claims 2 to 8.