Medium-entropy hard alloy cutter material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of hard alloy materials, and particularly relates to a medium-entropy hard alloy cutter material and a preparation method and application thereof. The medium-entropy hard alloy cutter material comprises medium-entropy carbides and medium-entropy alloys, the medium-entropy carbides are selected from WC, TaC and NbC or TaC, TiC and ZrC, and the materials bring excellent high-temperature hardness and wear resistance to the cutter material due to unique component design and structural characteristics of the materials; the medium-entropy alloy is selected from Fe powder, Co powder and Ni powder or Co powder, Ni powder and Cr powder, and the alloy has excellent comprehensive mechanical properties, so that the toughness and the overall strength of the cutter are effectively improved, and the stability and the durability of the cutter in the high-speed cutting process are ensured. According to the medium-entropy hard alloy cutter material disclosed by the invention, by virtue of the unique material composition and the preparation process, high hardness, excellent wear resistance, high cutting speed and high cutting precision are maintained at a high temperature. And meanwhile, the reliability and the service life of the cutter under complex machining conditions are ensured due to the excellent toughness of the cutter.

Description

Technical Field

[0001] The invention belongs to the technical field of cemented carbide materials, and specifically relates to a medium-entropy cemented carbide tool material and a preparation method and application thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] In view of the inherent contradiction between the pursuit of extreme hardness and good toughness in cemented carbide tool materials, a diversified strategy is currently adopted to seek the best balance between the two. Among them, medium-entropy cemented carbide aims to balance the contradiction between hardness and toughness through a carefully designed multi-component system. Medium-entropy cemented carbide not only inherits the high hardness and high wear resistance of carbide ceramics, but also improves its processability and toughness through the medium-entropy design strategy, becoming a key material in the future advanced manufacturing, aerospace, energy mining and other fields. Due to the good mechanical properties, stability in high temperature and high pressure environments, and excellent oxidation resistance and corrosion resistance of cemented carbide, the research on medium-entropy cemented carbide has become and will remain the mainstream and research hotspot of cemented carbide for a long time in the future.

[0004] However, the preparation process of medium-entropy cemented carbide still faces many challenges, especially how to achieve the dual goals of high density and excellent toughness. The specific strengthening and toughening mechanism of medium-entropy cemented carbide needs to be further explored. How to effectively combine traditional strengthening strategies with emerging medium-entropy design concepts to overcome the brittleness of the material and improve its comprehensive performance is a key issue that needs to be urgently addressed in current research. Solving these problems will not only promote the advancement of medium-entropy cemented carbide material science, but also lay a solid foundation for its practical application in a wider range of fields. Summary of the invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide a medium-entropy cemented carbide tool material and its preparation method and application. The present invention uses medium-entropy carbide as the main hard phase of cemented carbide, which further improves the hardness and wear resistance of the material; introduces medium-entropy alloy as the main bonding phase of cemented carbide, effectively prevents the abnormal growth of grains, and improves the material's antioxidant properties and corrosion resistance; adopts spark plasma sintering technology to obtain a medium-entropy cemented carbide tool material with synergistic effects among multiple components, precise controllable bonding phase content and optimal performance configuration.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] The first aspect of the present invention provides a medium-entropy cemented carbide tool material, which includes medium-entropy carbide and medium-entropy alloy; the composition of the medium-entropy carbide is selected from WC, TaC, NbC or TaC, TiC, ZrC; the composition of the medium-entropy alloy is selected from Fe powder, Co powder, Ni powder or Co powder, Ni powder, Cr powder.

[0008] Preferably, the carbides in the medium entropy carbide are mixed in a molar ratio of 1:1:1 to form a medium entropy carbide with a medium entropy value; the metal powders in the medium entropy alloy are mixed in a molar ratio of 1:1:1 to form a medium entropy alloy with a medium entropy value; wherein the powder particle size ratio of the medium entropy carbide to the medium entropy alloy is 1:1.

[0009] Preferably, the mass ratio of the medium entropy carbide to the medium entropy alloy is 88-92:8-12.

[0010] The second aspect of the present invention provides a method for preparing the medium entropy cemented carbide tool material according to the first aspect, comprising the following steps:

[0011] S1. Mixing three carbide suspensions to obtain a medium entropy carbide suspension, and then ball milling and drying to obtain a medium entropy carbide powder;

[0012] S2, mixing three metal powders to obtain a medium-entropy alloy suspension, and then ball-milling and drying to obtain a medium-entropy alloy powder;

[0013] S3, mixing medium entropy carbide powder and medium entropy alloy powder, heating in a water bath to obtain a medium entropy cemented carbide powder suspension, and ball milling and drying to obtain a medium entropy cemented carbide powder;

[0014] S4. Through the pressing and sintering process, the medium entropy cemented carbide tool material is obtained.

[0015] Preferably, in step S1, the carbide suspension is prepared by using anhydrous ethanol as a dispersion solvent, polyethylene glycol and polyvinyl pyrrolidone as dispersion media, and then heating and dispersing in a water bath;

[0016] Among them, the temperature of the water bath heating is 80-120°C, the time is 0.5-1.5h, the dispersion operation includes mechanical stirring and ultrasonic dispersion, and the dispersion operation time is 0.5-1.5h; further preferably, the temperature of the water bath heating is 100°C, the time is 1h, and the dispersion operation time is 1h.

[0017] Preferably, in step S1, the ball milling and drying refers to adding grinding balls to the medium entropy carbide suspension at a certain ball-to-material ratio, and after the ball milling is completed, drying in a vacuum drying oven and sieving to obtain medium entropy carbide powder;

[0018] Among them, the ball-to-material ratio is 35:1-65:1, the ball milling time is 18-30 hours, and the drying time is 1 hour-5 hours; further preferably, the ball-to-material ratio is 50:1, the ball milling time is 24 hours, and the drying time is 3 hours.

[0019] Preferably, in step S2, the medium entropy alloy suspension is prepared by using anhydrous ethanol as a dispersion solvent, polyethylene glycol and polyvinyl pyrrolidone as dispersion media, and then heating and dispersing in a water bath;

[0020] Among them, the temperature of the water bath heating is 80-120°C, the time is 0.5-1.5h, the dispersion operation includes mechanical stirring and ultrasonic dispersion, and the dispersion operation time is 0.5-1.5h; further preferably, the temperature of the water bath heating is 100°C, the time is 1h, and the dispersion operation time is 1h.

[0021] Preferably, in step S2, the ball milling and drying refers to adding grinding balls to the medium entropy alloy suspension at a certain ball-to-material ratio, and after the ball milling is completed, drying in a vacuum drying oven and sieving to obtain the medium entropy alloy powder;

[0022] Among them, the ball-to-material ratio is 35:1-65:1, the ball milling time is 18-30 hours, and the drying time is 1 hour-5 hours; further preferably, the ball-to-material ratio is 50:1, the ball milling time is 24 hours, and the drying time is 3 hours.

[0023] Preferably, in step S3, the water bath heating temperature is 80-120°C, the time is 0.25-0.75h, and the product after water bath heating is ultrasonically dispersed for 0.25-0.75h; further preferably, the water bath heating temperature is 100°C, the time is 0.5h, and the product after water bath heating is ultrasonically dispersed for 0.5h.

[0024] Preferably, in step S3, the ball milling and drying refers to adding grinding balls to the medium entropy cemented carbide powder suspension at a certain ball-to-material ratio, and after the ball milling is completed, drying in a vacuum drying oven and sieving to obtain the medium entropy cemented carbide powder;

[0025] Among them, the ball-to-material ratio is 35:1-65:1, the ball milling time is 18-30 hours, and the drying time is 1 hour-5 hours; further preferably, the ball-to-material ratio is 50:1, the ball milling time is 20 hours, and the drying time is 3 hours.

[0026] Preferably, in step S4, the pressing and molding refers to calculating the required weight of the medium-entropy alloy material powder according to the size of the mold, separating the contact part between the mold and the powder with graphite paper and loading the material.

[0027] Preferably, in step S4, the sintering process refers to a spark plasma sintering process, and the specific operation is: maintaining the vacuum degree at 1×10 -3 ~1×10 -2 Pa, heat to 1450-1650°C at 80-120°C / min, keep warm for 8-12min, then cool to 600-1000°C at 80-120°C / min and then cool with the furnace; from room temperature to 600-1000°C, the pressure of the applied pressure is maintained at 10-30MPa, and from 600-1000°C to 1450-1650°C, the pressure of the applied pressure is maintained at 40-50MPa.

[0028] Further preferably, the spark plasma sintering process is specifically performed as follows: the vacuum degree is maintained at 5×10 -3 Pa, heat to 1550℃ at 100℃ / min, keep warm for 10min, then cool to 800℃ at 100℃ / min and cool with the furnace; during the period from room temperature to 800℃, the applied pressure is maintained at 20MPa, and when 800℃~1550℃, the applied pressure is maintained at 45MPa.

[0029] The third aspect of the present invention provides an application of the medium-entropy cemented carbide tool material described in the first aspect and / or the medium-entropy cemented carbide tool material prepared by the preparation method described in the second aspect in cemented carbide materials.

[0030] The beneficial effects achieved by one or more technical solutions of the present invention are as follows:

[0031] (1) The present invention selects medium-entropy carbide (WTaNb)C or (TaTiZr)C as the hard phase, selects FeCoNi or CoNiCr medium-entropy alloy as the bonding phase, and adopts spark plasma sintering to prepare medium-entropy cemented carbide, which breaks the bottleneck of traditional cemented carbide material design and has higher stability and flexibility in microstructure control.

[0032] (2) The medium-entropy cemented carbide tool material prepared by the present invention can achieve a combination of multiple excellent properties in terms of performance. Based on the "cocktail effect" of the medium-entropy material, the medium-entropy hard phase and medium-entropy bonding phase with different properties can be obtained by controlling the types of elements, thereby adjusting the performance of the cemented carbide and realizing performance-driven cemented carbide tool material design.

[0033] (3) Compared with traditional WC-Co cemented carbide, medium entropy cemented carbide has greatly enhanced the hardness of cemented carbide by using medium entropy carbide hard phase of (WTaNb)C or (TaTiZr)C, and improved the fracture toughness of cemented carbide by using medium entropy alloy binder phase of FeCoNi or CoNiCr.

[0034] Compared with single-phase medium-entropy carbides, the medium-entropy carbides (WTaNb)C or (TaTiZr)C of the present invention as hard phases can significantly enhance the hardness of cemented carbide tool materials; and the types of carbides of the present invention ensure that a single-phase medium-entropy compound hard phase can be formed, thereby improving the density and mechanical properties of cemented carbide tool materials;

[0035] Compared with single-phase medium-entropy alloys, the FeCoNi or CoNiCr medium-entropy alloys of the present invention can significantly enhance the fracture toughness and density of cemented carbide tool materials.

[0036] (3) The spark plasma sintering method adopted in the present invention can achieve complete densification of medium entropy cemented carbide tool materials while suppressing grain growth. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The SEM microstructure image and EDS element analysis diagram of the medium-entropy cemented carbide tool material prepared by the present invention.

[0038] Figure 2 These are the XRD diagrams of the (TaTiZr)C-10FeCoNi medium-entropy cemented carbide tool material in Example 3 of the present invention and the (WTiV)C-10FeCoNi cemented carbide tool material in Comparative Example 1. DETAILED DESCRIPTION

[0039] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0040] As mentioned above, how to achieve the dual goals of high density and excellent strength and toughness of medium-entropy cemented carbide, and how to effectively combine traditional strengthening strategies with emerging medium-entropy design concepts to overcome the brittleness of the material and improve its comprehensive performance are key issues that need to be urgently addressed in current research.

[0041] A first typical embodiment of the present invention provides a medium-entropy cemented carbide tool material, wherein the medium-entropy cemented carbide tool material comprises medium-entropy carbides and medium-entropy alloys; the composition of the medium-entropy carbides is selected from WC, TaC, NbC or TaC, TiC, ZrC; the composition of the medium-entropy alloy is selected from Fe powder, Co powder, Ni powder or Co powder, Ni powder, Cr powder.

[0042] In one or more embodiments of this embodiment, the carbides in the intermediate entropy carbide are mixed in a molar ratio of 1:1:1 to form an intermediate entropy carbide with an intermediate entropy value; the metal powders in the intermediate entropy alloy are mixed in a molar ratio of 1:1:1 to form an intermediate entropy alloy with an intermediate entropy value; wherein the powder particle size ratio of the intermediate entropy carbide to the intermediate entropy alloy is 1:1.

[0043] Preferably, the mass ratio of the medium entropy carbide to the medium entropy alloy is 88-92:8-12.

[0044] A second typical embodiment of the present invention provides a method for preparing the above-mentioned medium entropy cemented carbide tool material, comprising the following steps:

[0045] S1. Mixing three carbide suspensions to obtain a medium entropy carbide suspension, and then ball milling and drying to obtain a medium entropy carbide powder;

[0046] S2, mixing three metal powders to obtain a medium-entropy alloy suspension, and then ball-milling and drying to obtain a medium-entropy alloy powder;

[0047] S3, mixing medium entropy carbide powder and medium entropy alloy powder, heating in a water bath to obtain a medium entropy cemented carbide powder suspension, and ball milling and drying to obtain a medium entropy cemented carbide powder;

[0048] S4. Through the pressing and sintering process, the medium entropy cemented carbide tool material is obtained.

[0049] In one or more examples of this embodiment, in step S1, the carbide suspension is prepared by using anhydrous ethanol as a dispersion solvent, polyethylene glycol and polyvinyl pyrrolidone as dispersion media, and then heating and dispersing in a water bath;

[0050] Among them, the temperature of the water bath heating is 80-120°C, the time is 0.5-1.5h, the dispersion operation includes mechanical stirring and ultrasonic dispersion, and the dispersion operation time is 0.5-1.5h; further preferably, the temperature of the water bath heating is 100°C, the time is 1h, and the dispersion operation time is 1h.

[0051] In one or more examples of this embodiment, in step S1, the ball milling and drying refers to adding grinding balls to the medium entropy carbide suspension at a certain ball-to-material ratio, and after the ball milling is completed, drying in a vacuum drying oven and sieving to obtain medium entropy carbide powder;

[0052] Among them, the ball-to-material ratio is 35:1-65:1, the ball milling time is 18-30 hours, and the drying time is 1 hour-5 hours; further preferably, the ball-to-material ratio is 50:1, the ball milling time is 24 hours, and the drying time is 3 hours.

[0053] In one or more examples of this embodiment, in step S2, the medium entropy alloy suspension is prepared by using anhydrous ethanol as a dispersion solvent, polyethylene glycol and polyvinyl pyrrolidone as dispersion media, and then heating and dispersing in a water bath;

[0054] Among them, the temperature of the water bath heating is 80-120°C, the time is 0.5-1.5h, the dispersion operation includes mechanical stirring and ultrasonic dispersion, and the dispersion operation time is 0.5-1.5h; further preferably, the temperature of the water bath heating is 100°C, the time is 1h, and the dispersion operation time is 1h.

[0055] In one or more examples of this embodiment, in step S2, the ball milling and drying refers to adding grinding balls to the medium entropy alloy suspension at a certain ball-to-material ratio, and after the ball milling is completed, drying in a vacuum drying oven and sieving to obtain the medium entropy alloy powder;

[0056] Among them, the ball-to-material ratio is 35:1-65:1, the ball milling time is 18-30 hours, and the drying time is 1 hour-5 hours; further preferably, the ball-to-material ratio is 50:1, the ball milling time is 24 hours, and the drying time is 3 hours.

[0057] In one or more embodiments of this embodiment, in step S3, the water bath heating temperature is 80-120°C, the time is 0.25-0.75h, and the product after water bath heating is ultrasonically dispersed for 0.25-0.75h; further preferably, the water bath heating temperature is 100°C, the time is 0.5h, and the product after water bath heating is ultrasonically dispersed for 0.5h.

[0058] In one or more examples of this embodiment, in step S3, the ball milling and drying refers to adding grinding balls to the medium entropy cemented carbide powder suspension according to a certain ball-to-material ratio, and after the ball milling is completed, drying in a vacuum drying oven and sieving to obtain the medium entropy cemented carbide powder;

[0059] Among them, the ball-to-material ratio is 35:1-65:1, the ball milling time is 18-30 hours, and the drying time is 1 hour-5 hours; further preferably, the ball-to-material ratio is 50:1, the ball milling time is 20 hours, and the drying time is 3 hours.

[0060] In one or more examples of this embodiment, in step S4, the pressing molding refers to calculating the required weight of the medium-entropy alloy material powder according to the size of the mold, separating the contact part of the mold and the powder with graphite paper and loading the material.

[0061] In one or more embodiments of this embodiment, in step S4, the sintering process refers to a spark plasma sintering process, and the specific operation is: maintaining a vacuum degree of 1×10 -3 ~1×10 -2 Pa, heat to 1450-1650°C at 80-120°C / min, keep warm for 8-12min, then cool to 600-1000°C at 80-120°C / min and then cool with the furnace; from room temperature to 600-1000°C, the pressure of the applied pressure is maintained at 10-30MPa, and from 600-1000°C to 1450-1650°C, the pressure of the applied pressure is maintained at 40-50MPa.

[0062] In one or more embodiments of this embodiment, the spark plasma sintering process is specifically operated as follows: the vacuum degree is maintained at 5×10 -3 Pa, heat to 1550℃ at 100℃ / min, keep warm for 10min, then cool to 800℃ at 100℃ / min and cool with the furnace; during the period from room temperature to 800℃, the applied pressure is maintained at 20MPa, and when 800℃~1550℃, the applied pressure is maintained at 45MPa.

[0063] A third typical embodiment of the present invention provides an application of the above-mentioned medium-entropy cemented carbide tool material and / or the medium-entropy cemented carbide tool material prepared by the above-mentioned preparation method in cemented carbide materials.

[0064] The present invention will be further described in detail below in conjunction with specific embodiments. It should be noted that the specific embodiments are intended to explain the present invention rather than to limit it.

[0065] Example 1 :This embodiment provides a medium entropy cemented carbide tool material and a preparation method thereof

[0066] (1) Three carbide powders of WC, TaC and NbC with a particle size of 0.5 μm were used as raw materials and prepared in an equal molar ratio. Anhydrous ethanol was used as the dispersion solvent, polyethylene glycol and polyvinyl pyrrolidone were used as the dispersion medium, and three carbide suspensions were prepared respectively. They were heated in a water bath at 100°C for 1 hour for ultrasonic dispersion. Under mechanical stirring and ultrasonic dispersion, the three carbide suspensions were mixed to obtain a medium entropy carbide suspension, and ultrasonic dispersion was continued for 1 hour. Grinding balls were added at a ball-to-material ratio of 50:1, ball milled for 24 hours, and then dried in a vacuum drying oven at 100°C for 3 hours. The well-dispersed medium entropy carbide hard phase powder was obtained by sieving.

[0067] (2) Fe, Co, and Ni powders with a particle size of 0.5 μm were used as raw materials and prepared in an equal molar ratio. Anhydrous ethanol was used as the dispersion solvent, polyethylene glycol and polyvinyl pyrrolidone were used as the dispersion medium, and three metal powder suspensions were prepared respectively. They were ultrasonically dispersed in a water bath at 100°C for 1 hour. Under mechanical stirring and ultrasonic dispersion, the three metal powder suspensions were mixed to obtain a medium-entropy alloy suspension, and ultrasonic dispersion was continued for 1 hour. Grinding balls were added at a ball-to-material ratio of 50:1, ball milled for 24 hours, and then dried in a vacuum drying oven at 100°C for 3 hours. The well-dispersed medium-entropy alloy binder phase powder was obtained by sieving.

[0068] (3) The medium entropy carbide hard phase and the medium entropy alloy bonding phase are mixed in a mass ratio of 90:10.

[0069] (4) According to the proportion of step (3), the medium entropy carbide powder and the medium entropy alloy powder are mixed, and ultrasonic dispersion is performed in a water bath at 100° C. for 30 min to obtain a medium entropy cemented carbide powder suspension. Grinding balls are added at a ball-to-material ratio of 50:1, and ball milling is performed for 20 h. Then, the mixture is dried in a vacuum drying oven at 100° C. for 3 h, and sieved to obtain well-dispersed medium entropy cemented carbide powder.

[0070] (5) The spark plasma sintering process is used, and the vacuum degree is maintained at 1×10 -3 ~1×10 -2 Pa, heat to 1550℃ at 100℃ / min, keep warm for 10min, then cool to 800℃ at 100℃ / min and cool with the furnace; during the period from room temperature to 800℃, the pressure is maintained at 20MPa, and the pressure is maintained at 45MPa from 800 to 1550℃.

[0071] After the sintering process is completed, a medium-entropy cemented carbide tool material with a hard phase of single-phase medium-entropy carbide and a binder phase of single-phase medium-entropy alloy can be obtained.

[0072] Example 2 :This embodiment provides a medium entropy cemented carbide tool material and a preparation method thereof

[0073] (1) Three carbide powders of WC, TaC and NbC with a particle size of 0.5 μm were used as raw materials and prepared in an equal molar ratio. Anhydrous ethanol was used as the dispersion solvent, polyethylene glycol and polyvinyl pyrrolidone were used as the dispersion medium, and three carbide suspensions were prepared respectively. They were ultrasonically dispersed in a water bath at 100°C for 1 hour. Under mechanical stirring and ultrasonic dispersion, the three carbide suspensions were mixed to obtain a medium entropy carbide suspension, and ultrasonic dispersion was continued for 1 hour. Grinding balls were added at a ball-to-material ratio of 50:1, ball milled for 24 hours, and then dried in a vacuum drying oven at 100°C for 3 hours. The well-dispersed medium entropy carbide hard phase powder was obtained by sieving.

[0074] (2) Co, Ni, and Cr metal powders with a particle size of 0.5 μm were used as raw materials and prepared in an equal molar ratio. Anhydrous ethanol was used as the dispersion solvent, polyethylene glycol and polyvinyl pyrrolidone were used as the dispersion medium, and three metal powder suspensions were prepared respectively. They were ultrasonically dispersed in a water bath at 100°C for 1 hour. Under mechanical stirring and ultrasonic dispersion, the three metal powder suspensions were mixed to obtain a medium-entropy alloy suspension, and ultrasonic dispersion was continued for 1 hour. Grinding balls were added at a ball-to-material ratio of 50:1, ball milled for 24 hours, and then dried in a vacuum drying oven at 100°C for 3 hours. The well-dispersed medium-entropy alloy binder phase powder was obtained by sieving.

[0075] (3) The medium entropy carbide hard phase and the medium entropy alloy bonding phase are mixed in a mass ratio of 90:10.

[0076] (4) According to the proportion of step (3), the medium entropy carbide powder and the medium entropy alloy powder are mixed, and ultrasonic dispersion is performed in a water bath at 100° C. for 30 min to obtain a medium entropy cemented carbide powder suspension. Grinding balls are added at a ball-to-material ratio of 50:1, and ball milling is performed for 20 h. Then, the mixture is dried in a vacuum drying oven at 100° C. for 3 h, and sieved to obtain well-dispersed medium entropy cemented carbide powder.

[0077] (5) The spark plasma sintering process is used, and the vacuum degree is maintained at 1×10 -3 ~1×10 -2 Pa, heat to 1550℃ at 100℃ / min, keep warm for 10min, then cool to 800℃ at 100℃ / min and cool with the furnace; during the period from room temperature to 800℃, the pressure is maintained at 20MPa, and the pressure is maintained at 45MPa from 800 to 1550℃.

[0078] After the sintering process is completed, a medium-entropy cemented carbide tool material with a hard phase of single-phase medium-entropy carbide and a binder phase of single-phase medium-entropy alloy can be obtained.

[0079] Example 3 :This embodiment provides a medium entropy cemented carbide tool material and a preparation method thereof

[0080] (1) TaC, TiC, and ZrC carbide powders with a particle size of 0.5 μm were used as raw materials and prepared in an equal molar ratio. Anhydrous ethanol was used as a dispersion solvent, and polyethylene glycol and polyvinyl pyrrolidone were used as dispersion media to prepare three carbide suspensions respectively, which were ultrasonically dispersed in a water bath at 100°C for 1 hour. Under mechanical stirring and ultrasonic dispersion, the three carbide suspensions were mixed to obtain a medium-entropy carbide suspension, which was ultrasonically dispersed for 1 hour. Grinding balls were added at a ball-to-material ratio of 50:1, ball milled for 24 hours, and then dried in a vacuum drying oven at 100°C for 3 hours. The well-dispersed medium-entropy carbide hard phase powder was obtained by sieving.

[0081] (2) Fe, Co, and Ni metal powders with a particle size of 0.5 μm were used as raw materials and prepared in an equal molar ratio. Anhydrous ethanol was used as the dispersion solvent, polyethylene glycol and polyvinyl pyrrolidone were used as the dispersion medium, and three metal powder suspensions were prepared respectively. They were ultrasonically dispersed in a water bath at 100°C for 1 hour. Under mechanical stirring and ultrasonic dispersion, the three metal powder suspensions were mixed to obtain a medium-entropy alloy suspension, and ultrasonic dispersion was continued for 1 hour. Grinding balls were added at a ball-to-material ratio of 50:1, ball milled for 24 hours, and then dried in a vacuum drying oven at 100°C for 3 hours. The well-dispersed medium-entropy alloy binder phase powder was obtained by sieving.

[0082] (3) The medium entropy carbide hard phase and the medium entropy alloy bonding phase are mixed in a mass ratio of 90:10.

[0083] (4) According to the proportion of step (3), the medium entropy carbide powder and the medium entropy alloy powder are mixed, and ultrasonic dispersion is performed in a water bath at 100° C. for 30 min to obtain a medium entropy cemented carbide powder suspension. Grinding balls are added at a ball-to-material ratio of 50:1, and ball milling is performed for 20 h. Then, the mixture is dried in a vacuum drying oven at 100° C. for 3 h, and sieved to obtain well-dispersed medium entropy cemented carbide powder.

[0084] (5) The spark plasma sintering process is used, and the vacuum degree is maintained at 1×10 -3 ~1×10 -2 Pa, heat to 1550℃ at 100℃ / min, keep warm for 10min, then cool to 800℃ at 100℃ / min and cool with the furnace; during the period from room temperature to 800℃, the pressure is maintained at 20MPa, and the pressure is maintained at 45MPa from 800 to 1550℃.

[0085] After the sintering process is completed, a medium-entropy cemented carbide tool material with a hard phase of single-phase medium-entropy carbide and a binder phase of single-phase medium-entropy alloy can be obtained.

[0086] Example 4 :This embodiment provides a medium entropy cemented carbide tool material and a preparation method thereof

[0087] (1) TaC, TiC, and ZrC carbide powders with a particle size of 0.5 μm were used as raw materials and prepared in an equal molar ratio. Anhydrous ethanol was used as a dispersing solvent, and polyethylene glycol and polyvinyl pyrrolidone were used as dispersing media to prepare three carbide suspensions respectively, which were ultrasonically dispersed in a water bath at 100°C for 1 h. Under mechanical stirring and ultrasonic dispersion, the three carbide suspensions were mixed to obtain a medium-entropy carbide suspension, which was ultrasonically dispersed for 1 h. Grinding balls were added at a ball-to-material ratio of 50:1, ball milled for 24 h, and then dried in a vacuum drying oven at 100°C for 3 h. The well-dispersed medium-entropy carbide hard phase powder was obtained by sieving.

[0088] (2) Co, Ni, and Cr metal powders with a particle size of 0.5 μm were used as raw materials and prepared in an equal molar ratio. Anhydrous ethanol was used as the dispersion solvent, polyethylene glycol and polyvinyl pyrrolidone were used as the dispersion medium, and three metal powder suspensions were prepared respectively. They were ultrasonically dispersed in a water bath at 100°C for 1 hour. Under mechanical stirring and ultrasonic dispersion, the three metal powder suspensions were mixed to obtain a medium-entropy alloy suspension, and ultrasonic dispersion was continued for 1 hour. Grinding balls were added at a ball-to-material ratio of 50:1, ball milled for 24 hours, and then dried in a vacuum drying oven at 100°C for 3 hours. The well-dispersed medium-entropy alloy binder phase powder was obtained by sieving.

[0089] (3) The medium entropy carbide hard phase and the medium entropy alloy bonding phase are mixed in a mass ratio of 90:10.

[0090] (4) According to the proportion of step (3), the medium entropy carbide powder and the medium entropy alloy powder are mixed, and ultrasonic dispersion is performed in a water bath at 100° C. for 30 min to obtain a medium entropy cemented carbide powder suspension. Grinding balls are added at a ball-to-material ratio of 50:1, and ball milling is performed for 20 h. Then, the mixture is dried in a vacuum drying oven at 100° C. for 3 h, and sieved to obtain well-dispersed medium entropy cemented carbide powder.

[0091] (5) The spark plasma sintering process is used, and the vacuum degree is maintained at 1×10 -3 ~1×10 -2 Pa, heat to 1550℃ at 100℃ / min, keep warm for 10min, then cool to 800℃ at 100℃ / min and cool with the furnace; during the period from room temperature to 800℃, the pressure is maintained at 20MPa, and the pressure is maintained at 45MPa from 800 to 1550℃.

[0092] After the sintering process is completed, a medium-entropy cemented carbide tool material with a hard phase of single-phase medium-entropy carbide and a binder phase of single-phase medium-entropy alloy can be obtained.

[0093] Comparative Example 1 :This comparative example provides a medium entropy cemented carbide tool material and a preparation method thereof

[0094] (1) Three carbide powders of WC, TiC and VC with a particle size of 0.5 μm were used as raw materials and prepared in an equal molar ratio. Anhydrous ethanol was used as the dispersion solvent, polyethylene glycol and polyvinyl pyrrolidone were used as the dispersion medium, and three carbide suspensions were prepared respectively. They were ultrasonically dispersed in a water bath at 100°C for 1 hour. Under mechanical stirring and ultrasonic dispersion, the three carbide suspensions were mixed to obtain a medium entropy carbide suspension, and ultrasonic dispersion was continued for 1 hour. Grinding balls were added at a ball-to-material ratio of 50:1, ball milled for 24 hours, and then dried in a vacuum drying oven at 100°C for 3 hours. The well-dispersed medium entropy carbide hard phase powder was obtained by sieving.

[0095] (2) Fe, Co, and Ni metal powders with a particle size of 0.5 μm were used as raw materials and prepared in an equal molar ratio. Anhydrous ethanol was used as the dispersion solvent, polyethylene glycol and polyvinyl pyrrolidone were used as the dispersion medium, and three metal powder suspensions were prepared respectively. They were ultrasonically dispersed in a water bath at 100°C for 1 hour. Under mechanical stirring and ultrasonic dispersion, the three metal powder suspensions were mixed to obtain a medium-entropy alloy suspension, and ultrasonic dispersion was continued for 1 hour. Grinding balls were added at a ball-to-material ratio of 50:1, ball milled for 24 hours, and then dried in a vacuum drying oven at 100°C for 3 hours. The well-dispersed medium-entropy alloy binder phase powder was obtained by sieving.

[0096] (3) The medium entropy carbide hard phase and the medium entropy alloy bonding phase are mixed in a mass ratio of 90:10.

[0097] (4) According to the proportions in step (3), the medium entropy carbide powder and the medium entropy alloy powder are mixed, and ultrasonic dispersion is performed in a water bath at 100° C. for 30 min to obtain a medium entropy cemented carbide powder suspension. Grinding balls are added at a ball-to-material ratio of 50:1, and the mixture is ball-milled for 20 h. The mixture is then dried in a vacuum drying oven at 100° C. for 3 h, and sieved to obtain well-dispersed medium entropy cemented carbide powder.

[0098] (5) The spark plasma sintering process is used, and the vacuum degree is maintained at 1×10 -3 ~1×10 -2 Pa, heat to 1550℃ at 100℃ / min, keep warm for 10min, then cool to 800℃ at 100℃ / min and cool with the furnace; during the period from room temperature to 800℃, the pressure is maintained at 20MPa, and the pressure is maintained at 45MPa from 800 to 1550℃.

[0099] The above process is continued until the sintering process is finished. Figure 2 As shown, there is an obvious difference in the XRD patterns of the two, that is, the material prepared in Comparative Example 1 does not form a single-phase medium-entropy carbide hard phase, but exists in the form of a mixed phase of multiple binary carbides.

[0100] Comparative Example 2 :This comparative example provides a medium entropy cemented carbide tool material and a preparation method thereof

[0101] (1) The WC hard phase and the Co bonding phase are mixed in a mass ratio of 90:10.

[0102] (2) According to the proportion of step (1), the medium entropy carbide powder and the medium entropy alloy powder are mixed, and ultrasonic dispersion is performed in a water bath at 100°C for 30 minutes to obtain a medium entropy cemented carbide powder suspension. Grinding balls are added at a ball-to-material ratio of 50:1, and ball milling is performed for 20 hours. Then, the powder is dried in a vacuum drying oven at 100°C for 3 hours, and the powder is sieved to obtain a well-dispersed WC-Co cemented carbide powder.

[0103] (3) The spark plasma sintering process is used, and the vacuum degree is maintained at 1×10 -3 ~1×10 -2 Pa, heat to 1550℃ at 100℃ / min, keep warm for 10min, then cool to 800℃ at 100℃ / min and cool with the furnace; during the period from room temperature to 800℃, the pressure is maintained at 20MPa, and the pressure is maintained at 45MPa from 800 to 1550℃.

[0104] The above steps are followed until the sintering process is completed, and a WC-Co cemented carbide tool material with a hard phase of WC and a bonding phase of Co can be obtained.

[0105] Comparative Example 3 :This comparative example provides a medium entropy bonding phase cemented carbide tool material and a preparation method thereof

[0106] (1) Co, Ni, and Cr metal powders with a particle size of 0.5 μm were used as raw materials and prepared in an equal molar ratio. Anhydrous ethanol was used as the dispersion solvent, polyethylene glycol and polyvinyl pyrrolidone were used as the dispersion medium, and three metal powder suspensions were prepared respectively. They were ultrasonically dispersed in a water bath at 100°C for 1 hour. Under mechanical stirring and ultrasonic dispersion, the three metal powder suspensions were mixed to obtain a medium-entropy alloy suspension, and ultrasonic dispersion was continued for 1 hour. Grinding balls were added at a ball-to-material ratio of 50:1, ball milled for 24 hours, and then dried in a vacuum drying oven at 100°C for 3 hours. The well-dispersed medium-entropy alloy binder phase powder was obtained by sieving.

[0107] (2) The WC hard phase and the medium entropy alloy bonding phase are mixed in a mass ratio of 90:10.

[0108] (3) According to the proportions in step (2), WC powder and medium entropy alloy powder are mixed, and ultrasonic dispersion is performed in a water bath at 100°C for 30 minutes to obtain a medium entropy binder phase cemented carbide powder suspension. Grinding balls are added at a ball-to-material ratio of 50:1, and ball milling is performed for 20 hours. Then, the powder is dried in a vacuum drying oven at 100°C for 3 hours, and then sieved to obtain a well-dispersed medium entropy binder phase cemented carbide powder.

[0109] (4) The spark plasma sintering process is used, and the vacuum degree is maintained at 1×10 -3 ~1×10 -2 Pa, heat to 1550℃ at 100℃ / min, keep warm for 10min, then cool to 800℃ at 100℃ / min and cool with the furnace; during the period from room temperature to 800℃, the pressure is maintained at 20MPa, and the pressure is maintained at 45MPa from 800 to 1550℃.

[0110] The above steps are performed until the sintering process is completed, and a medium-entropy bonding phase cemented carbide tool material having a hard phase WC and a bonding phase being a single-phase medium-entropy alloy can be obtained.

[0111] Comparative Example 4: This comparative example provides a medium entropy hard phase cemented carbide tool material and a preparation method thereof

[0112] (1) Three carbide powders of WC, TaC and NbC with a particle size of 0.5 μm were used as raw materials and prepared in an equal molar ratio. Anhydrous ethanol was used as the dispersion solvent, polyethylene glycol and polyvinyl pyrrolidone were used as the dispersion medium, and three carbide suspensions were prepared respectively. They were ultrasonically dispersed in a water bath at 100°C for 1 hour. Under mechanical stirring and ultrasonic dispersion, the three carbide suspensions were mixed to obtain a medium entropy carbide suspension, and ultrasonic dispersion was continued for 1 hour. Grinding balls were added at a ball-to-material ratio of 50:1, ball milled for 24 hours, and then dried in a vacuum drying oven at 100°C for 3 hours. The well-dispersed medium entropy carbide hard phase powder was obtained by sieving.

[0113] (2) The medium entropy carbide hard phase and the Co bonding phase are mixed in a mass ratio of 90:10.

[0114] (3) According to the proportion of step (2), the medium entropy carbide powder and the Co metal powder are mixed, and ultrasonic dispersion is performed in a water bath at 100°C for 30 minutes to obtain a medium entropy hard phase cemented carbide powder suspension. Grinding balls are added at a ball-to-material ratio of 50:1, ball milling is performed for 20 hours, and then dried in a vacuum drying oven at 100°C for 3 hours, and sieved to obtain a well-dispersed medium entropy hard phase cemented carbide powder.

[0115] (4) The spark plasma sintering process is used, and the vacuum degree is maintained at 1×10 -3 ~1×10 -2 Pa, heat to 1550℃ at 100℃ / min, keep warm for 10min, then cool to 800℃ at 100℃ / min and cool with the furnace; during the period from room temperature to 800℃, the pressure is maintained at 20MPa, and the pressure is maintained at 45MPa from 800 to 1550℃.

[0116] After the sintering process is completed, a medium-entropy hard phase cemented carbide tool material with a hard phase of single-phase medium-entropy carbide and a bonding phase of Co can be obtained.

[0117] Test Example 1 :

[0118] This test example tests the relevant properties of the medium entropy cemented carbide tool materials obtained in Examples 1 to 4 and Comparative Examples 1 to 4, as shown in Table 1:

[0119] Table 1

[0120]

[0121] It can be seen from the data in Table 1 that the hardness, fracture toughness and density of the medium-entropy cemented carbide tool materials prepared in Examples 1 to 4 of the present invention are significantly improved.

[0122] Compared with Examples 1 to 4, no single-phase medium entropy carbide hard phase was formed in Comparative Example 1, and the presence of the binary carbide mixed phase reduced the density and mechanical properties of the cemented carbide tool material;

[0123] Comparison of Comparative Example 2 with the embodiment of the present invention shows that the present invention can significantly improve the overall mechanical properties of cemented carbide tools by replacing the single-phase medium-entropy carbide of WC and the single-phase medium-entropy alloy of Co.

[0124] Comparison between Comparative Example 3 and the embodiment of the present invention shows that the present invention can significantly enhance the hardness of cemented carbide tool materials by replacing the single-phase medium-entropy carbide of WC.

[0125] Comparison of Comparative Example 4 with the embodiments of the present invention shows that the present invention can significantly enhance the fracture toughness and density of cemented carbide tool materials by replacing the single-phase medium entropy alloy of Co.

[0126] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A medium entropy cemented carbide tool material, characterized in that: The medium-entropy cemented carbide tool material includes medium-entropy carbides and medium-entropy alloys; the composition of the medium-entropy carbides is selected from WC, TaC, NbC or TaC, TiC, ZrC; the composition of the medium-entropy alloy is selected from Fe powder, Co powder, Ni powder or Co powder, Ni powder, Cr powder.

2. The medium entropy cemented carbide tool material according to claim 1, characterized in that: The carbides in the medium entropy carbide are mixed in a molar ratio of 1:1:1 to form a medium entropy carbide with a medium entropy value; the metal powders in the medium entropy alloy are mixed in a molar ratio of 1:1:1 to form a medium entropy alloy with a medium entropy value; wherein the powder particle size ratio of the medium entropy carbide to the medium entropy alloy is 1:

1.

3. The medium entropy cemented carbide tool material according to claim 1, characterized in that: The mass ratio of the medium entropy carbide to the medium entropy alloy is 88-92:8-12.

4. A method for preparing a medium entropy cemented carbide tool material according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1, mixing three carbide suspensions to obtain a medium entropy carbide suspension, and then ball milling and drying to obtain a medium entropy carbide powder; S2, mixing three metal powders to obtain a medium-entropy alloy suspension, and then ball-milling and drying to obtain a medium-entropy alloy powder; S3, mixing medium entropy carbide powder and medium entropy alloy powder, heating in a water bath to obtain a medium entropy cemented carbide powder suspension, and ball milling and drying to obtain medium entropy cemented carbide powder; S4. Through the pressing and sintering process, the medium entropy cemented carbide tool material is obtained.

5. The preparation method according to claim 4, characterized in that: In step S1, the carbide suspension is prepared by using anhydrous ethanol as a dispersion solvent, polyethylene glycol and polyvinyl pyrrolidone as dispersion media, and then by water bath heating and dispersion operation; wherein the water bath heating temperature is 80-120°C, the time is 0.5-1.5h, the dispersion operation includes mechanical stirring and ultrasonic dispersion, and the dispersion operation time is 0.5-1.5h; preferably, the water bath heating temperature is 100°C, the time is 1h, and the dispersion operation time is 1h; The ball milling and drying refers to adding grinding balls into the intermediate entropy carbide suspension according to a certain ball-to-material ratio, and after the ball milling is completed, drying in a vacuum drying oven and sieving to obtain intermediate entropy carbide powder; wherein the ball-to-material ratio is 35:1 to 65:1, the ball milling time is 18 to 30 hours, and the drying time is 1 hour to 5 hours; preferably, the ball-to-material ratio is 50:1, the ball milling time is 24 hours, and the drying time is 3 hours.

6. The preparation method according to claim 4, characterized in that: In step S2, the medium entropy alloy suspension is prepared by using anhydrous ethanol as a dispersion solvent, polyethylene glycol and polyvinyl pyrrolidone as dispersion media, and then by water bath heating and dispersion operation; wherein the water bath heating temperature is 80-120°C, the time is 0.5-1.5h, the dispersion operation includes mechanical stirring and ultrasonic dispersion, and the dispersion operation time is 0.5-1.5h; preferably, the water bath heating temperature is 100°C, the time is 1h, and the dispersion operation time is 1h; The ball milling and drying refers to adding grinding balls into the medium entropy alloy suspension according to a certain ball-to-material ratio, and after the ball milling is completed, drying in a vacuum drying oven and sieving to obtain the medium entropy alloy powder; wherein the ball-to-material ratio is 35:1 to 65:1, the ball milling time is 18 to 30 hours, and the drying time is 1 hour to 5 hours; preferably, the ball-to-material ratio is 50:1, the ball milling time is 24 hours, and the drying time is 3 hours.

7. The preparation method according to claim 4, characterized in that: In step S3, the water bath heating temperature is 80-120°C, the time is 0.25-0.75h, and the time of ultrasonic dispersion of the product after water bath heating is 0.25-0.75h; preferably, the water bath heating temperature is 100°C, the time is 0.5h, and the time of ultrasonic dispersion of the product after water bath heating is 0.5h; The ball milling and drying refers to adding grinding balls into the medium entropy cemented carbide powder suspension according to a certain ball-to-material ratio, and after the ball milling is completed, it is dried in a vacuum drying oven and sieved to obtain the medium entropy cemented carbide powder; wherein the ball-to-material ratio is 35:1 to 65:1, and the ball milling time is 18 to 30 hours; further preferably, the ball-to-material ratio is 50:1, and the ball milling time is 20 hours.

8. The preparation method according to claim 4, characterized in that: In step S4, the pressing molding refers to calculating the required weight of the medium-entropy alloy material powder according to the size of the mold, separating the contact part of the mold and the powder with graphite paper and loading the material.

9. The preparation method according to claim 4, characterized in that: In step S4, the sintering process refers to the spark plasma sintering process, and the specific operation is: the vacuum degree is maintained at 1×10 -3 ~1×10 -2 Pa, heat to 1450-1650°C at 80-120°C / min, keep warm for 8-20min, then cool to 600-1000°C at 80-150°C / min and then cool with the furnace; from room temperature to 600-1000°C, the pressure of the applied pressure is maintained at 10-30MPa, and from 600-1000°C to 1450-1650°C, the pressure of the applied pressure is maintained at 40-50MPa; Preferably, the spark plasma sintering process is specifically performed as follows: the vacuum degree is maintained at 5×10 -3 Pa, heat to 1550℃ at 100℃ / min, keep warm for 10min, then cool to 800℃ at 100℃ / min and cool with the furnace; during the period from room temperature to 800℃, the applied pressure is maintained at 20MPa, and when 800℃~1550℃, the applied pressure is maintained at 45MPa.

10. Use of the medium-entropy cemented carbide tool material according to any one of claims 1 to 3 and / or the medium-entropy cemented carbide tool material prepared by the preparation method according to any one of claims 4 to 9 in cemented carbide materials.

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