High-entropy double-phase metal ceramic tool and mold material and preparation method thereof

Abstract

The invention relates to the technical field of metal ceramic materials, and discloses a high-entropy double-phase metal ceramic tool and mold material and a preparation method thereof.The high-entropy double-phase metal ceramic tool and mold material comprises, by weight, 30-60 parts of high-entropy ceramic phase metal powder, 40-70 parts of high-entropy alloy phase powder and 0.5-2 parts of guanidyl graphene; the high-entropy alloy phase powder comprises Fe powder, Co powder, Ni powder, Cr powder and Mn powder; the surface of guanidyl graphene contains a large number of Schiff base guanidine groups, an iron-cobalt-nickel alloy layer is formed on the surface of the high-entropy ceramic phase metal powder, a strong chemical coordination effect is formed between the guanidyl graphene and metal elements such as iron, cobalt and nickel in the high-entropy alloy phase powder, the interface strength is improved, a three-stage sintering process is adopted, the material shows higher compression strength, and the performance of the material is improved. Rockwell hardness and fracture toughness.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cermet materials, in particular to a high-entropy dual-phase cermet tool material and a preparation method thereof. BACKGROUND

[0002] With the rapid development of modern industry, the performance requirements of tool materials are becoming higher and higher. Traditional cermet tool materials (such as WC-Co hard alloy) have problems such as fast high-temperature strength decay and poor thermal shock resistance, and the comprehensive performance of key properties such as hardness, toughness, wear resistance and high-temperature stability is not good. When facing complex working conditions and high strength use, it is often difficult to meet the demand. In recent years, high-entropy materials have attracted attention due to their unique performance advantages. The emergence of high-entropy alloys and high-entropy ceramics brings new opportunities to solve these problems.

[0003] However, the existing high-entropy cermet materials mostly adopt the structure of "high-entropy ceramic + conventional alloy", and there are still deficiencies in the regulation and optimization of the phase structure, which fails to fully develop the potential of high-entropy materials. At the same time, high-entropy materials have the problem of densification during sintering, and the interfacial bonding strength between ceramic and metal is low, which affects the overall performance of the material. Therefore, it is of great practical significance and application value to develop a high-entropy dual-phase cermet tool material with high performance, innovative structure and preparation process.

[0004] The bottleneck of the prior art is that a single high-entropy phase cannot balance strength and toughness, traditional sintering process cannot realize interface compatibility control of high-entropy ceramic / metal, and lack of cross-scale structure design leads to insufficient high-temperature performance. SUMMARY

[0005] The technical problem solved by the present application is to provide a high-entropy dual-phase cermet tool material with high strength and high hardness and a preparation method thereof.

[0006] The technical scheme of the present application is a high-entropy dual-phase cermet tool material and a preparation method thereof. The raw materials include 30-60 parts by weight of high-entropy ceramic phase metal powder, 40-70 parts by weight of high-entropy alloy phase powder, and 0.5-2 parts by weight of guanidyl graphene. The high-entropy alloy phase powder includes any one or combination of Fe powder, Co powder, Ni powder, Cr powder and Mn powder.

[0007] The preparation method of the high-entropy dual-phase cermet tool material is as follows:

[0008] (1) Add graphene oxide to N,N-dimethylformamide, ultrasonically disperse, then add 5-hydroxyisophthalaldehyde guanidine, 4-dimethylaminopyridine and dicyclohexyl carbodiimide, stir for esterification reaction, then filter, wash the filter cake with water and ethanol, and dry to obtain guanidyl graphene.

[0009] (2) Ti powder, V powder, Nb powder, Zr powder, Hf powder are ball-mixed, placed in a sintering furnace, sintered in an inert atmosphere, and after cooling, ball-milled to obtain high-entropy ceramic phase powder.

[0010] (3) Ferrous sulfate, cobalt sulfate, nickel sulfate, and sodium phosphite are added to deionized water to configure a chemical plating solution, and high-entropy ceramic phase powder is added. After stirring and reaction, suction filtration, water washing, and drying, high-entropy ceramic phase metal powder is obtained. The surface of the high-entropy ceramic phase powder is chemically plated with a high-entropy alloy phase metal layer, and the thickness of the plating layer is controlled at 60-100 nm to form a core-shell structure composite powder.

[0011] (4) The high-entropy alloy phase powder, high-entropy ceramic phase metal powder, and guanidyl graphene are ball-mixed and then placed in a sintering furnace. A three-stage sintering process is adopted, specifically: first, in a vacuum environment, the temperature is raised to 600-700℃ at a rate of 5-10℃ / min, and the powder is kept at this temperature for 30-45 min to fully discharge the adsorbed gas in the powder, and at the same time, the guanidyl of graphene and the metal elements on the surface of the metal powder undergo physical adsorption and chemical coordination; then, the temperature is raised to 1000-1100℃ at a rate of 10-15℃ / min, and the powder is kept at this temperature for 15-25 min. In this stage, the high-entropy alloy phase plating layer in the core-shell structure begins to partially melt and preliminarily combines with the high-entropy ceramic phase powder, and at the same time, graphene further diffuses to the ceramic / metal interface to enhance the interface bonding; finally, argon gas is introduced, and the pressure in the sintering furnace is controlled at 30-50 MPa. The temperature is raised to 1200-1400℃ at a rate of 3-5℃ / min, and the powder is kept at this temperature for 10-20 min to fully densify the powder and form a high-entropy dual-phase metal ceramic blank. After cooling, a high-entropy dual-phase metal ceramic tool material is obtained.

[0012] Further, in (1), the reaction temperature is 45-60℃, and the reaction time is 18-36h.

[0013] Further, in (1), the mass ratio of graphene oxide, 5-hydroxyisophthalaldehyde guanidine, 4-dimethylamino pyridine, and dicyclohexyl carbodiimide is 100:(10-60):(9-58):(2-13).

[0014] Further, in (2), the mass ratio of Ti powder, V powder, Nb powder, Zr powder, and Hf powder is (46-54):(22-36):(15-22):(1-4):(0.5-1.2).

[0015] Further, in (2), the inert atmosphere is nitrogen or argon, the pressure in the sintering furnace is 30-40 MPa, the sintering temperature is 1100-1300℃, and the sintering time is 1-1.5h.

[0016] Further, the concentration of ferrous sulfate in the electroless plating solution in (3) is 14-33 g / L, the concentration of cobalt sulfate is 6-14 g / L, the concentration of nickel sulfate is 10-22 g / L, and the concentration of sodium phosphite is 11-27 g / L.

[0017] Further, the temperature of the reaction in (3) is 75-90 DEG C, and the reaction time is 60-90 min.

[0018] Further, the mass ratio of Fe powder, Co powder, Ni powder, Cr powder and Mn powder in the high-entropy alloy phase powder in (4) is (47-55):(13-20):(16-25):(4-9):(3-7).

[0019] Further, the preparation method of 5-hydroxyisophthalaldehyde guanidine is as follows: 5-hydroxyisophthalaldehyde and bicarbonate guanidine with a molar ratio of 1:(2.4-2.8) are added into ethanol, a hydrochloric acid solution with a mass fraction of 30-37% is added dropwise, heated to 65-75 DEG C, and condensed refluxed for 5-7 h, then distilled under reduced pressure, the product is added into saturated sodium bicarbonate aqueous solution, extracted with ethyl acetate, the organic phase is distilled under reduced pressure, and the product is recrystallized in ethanol to obtain 5-hydroxyisophthalaldehyde guanidine.

[0020] The present application has the beneficial technical effects that: the hydroxyl group of 5-hydroxyisophthalaldehyde and the carboxyl group on the surface of graphene oxide are subjected to esterification reaction to obtain guanidino graphene, so that a large number of Schiff base guanidino groups are introduced on the surface of graphene.

[0021] The present application uses Ti powder, V powder, Nb powder, Zr powder and Hf powder as high-entropy ceramic phase, forms an iron-cobalt-nickel alloy layer on the surface by electroless plating, forms a unique core-shell structure, and then is subjected to three-stage sintering process with Fe-Co-Ni-Cr-Mn high-entropy alloy phase powder and guanidino graphene to obtain high-entropy dual-phase metal ceramic tool material. The iron-cobalt-nickel alloy layer formed on the surface of the high-entropy ceramic phase metal powder of the core-shell structure improves the interfacial compatibility between the high-entropy ceramic phase metal powder and the Fe-Co-Ni-Cr-Mn high-entropy alloy phase powder, promotes element diffusion and interfacial bonding in the sintering process, helps to solve the sintering densification problem of high-entropy materials, and thus improves the internal density and mechanical properties of the material.

[0022] The guanidino graphene of the present application contains a large number of Schiff base guanidino groups, forms an iron-cobalt-nickel alloy layer on the surface of the high-entropy ceramic phase metal powder, and forms strong chemical coordination with metal elements such as iron, cobalt and nickel in the high-entropy alloy phase powder, so as to improve the interfacial strength between graphene and the high-entropy ceramic phase metal powder and the high-entropy alloy phase powder, and better promote the formation of metal ceramic carbide reinforcing phase in the high-temperature sintering process of graphene and the high-entropy ceramic phase metal powder and the high-entropy alloy phase powder, and further improve the mechanical strength of the material.

[0023] The present application adopts a three-stage sintering process. In the first stage of sintering, the adsorbed gas in the metal powder is fully discharged, and the guanidine group of graphene physically adsorbs and chemically coordinates with the metal elements on the surface of the metal powder. In the second stage of sintering, the high-entropy alloy phase plating layer in the core-shell structure begins to partially melt and preliminarily combines with the high-entropy ceramic phase powder, and the graphene further diffuses to the ceramic / metal interface to enhance the interface bonding. In the third stage of sintering, the metal powder is fully densified to form a high-entropy dual-phase cermet blank. The physical and chemical change characteristics at different temperature stages are reasonably controlled, the heating rate and the sintering time are controlled, the sintering efficiency and the densification of the material are improved, and the material exhibits higher compressive strength, Rockwell hardness and fracture toughness. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is an electron micrograph of the high-entropy dual-phase cermet tooling material.

[0025] Figure 2 is an elemental distribution map of the high-entropy dual-phase cermet tooling material. DETAILED DESCRIPTION

[0026] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

[0027] Example 1:

[0028] (1) 15 mmol of 5-hydroxyisophthalaldehyde, 36 mmol of carbamate guanidine, 4 mL of 30% hydrochloric acid solution were added to 60 mL of ethanol, heated to 65°C, and condensed refluxed for 7 h. The product was added to saturated sodium bicarbonate aqueous solution, extracted with ethyl acetate, and the organic phase was distilled under reduced pressure. The product was recrystallized in ethanol to obtain 5-hydroxyisophthalaldehyde carbamate guanidine. The reaction formula is:

[0029]

[0030] (2) 200 mg of graphene oxide was added to 150 mL of N,N-dimethylformamide, ultrasonically dispersed, and then 20 mg of 5-hydroxyisophthalaldehyde carbamate guanidine, 18 mg of 4-dimethylaminopyridine, and 4 mg of dicyclohexyl carbodiimide were added. The mixture was stirred at 45°C for 24 h, filtered, washed with water and ethanol, and dried to obtain guanidine graphene.

[0031] (3) 522 g of Ti powder, 276 g of V powder, 180 g of Nb powder, 15 g of Zr powder, and 7 g of Hf powder are ball-mixed and placed in a sintering furnace, heated to 1200°C at a heating rate of 10°C / min in an argon atmosphere, and sintered for 1.5 h with the sintering furnace pressure controlled at 30 MPa. After cooling, the sintered product is ball-milled to obtain a high-entropy ceramic phase powder.

[0032] (4) A chemical plating solution is prepared by adding 14 g of ferrous sulfate, 6 g of cobalt sulfate, 10 g / L of nickel sulfate, and 11 g / L of sodium phosphite to 1 L of deionized water. Then, 2.5 kg of the high-entropy ceramic phase powder is added, heated to 80°C, and stirred for 60 min. After filtration, washing, and drying, a high-entropy ceramic phase metal powder with a core-shell structure is obtained.

[0033] (5) 600 g of a high-entropy alloy phase powder composed of Fe powder, Co powder, Ni powder, Cr powder, and Mn powder in a mass ratio of 49:20:18:9:4, and 400 g of the high-entropy ceramic phase metal powder with a core-shell structure are ball-mixed for 60 min, and then placed in a sintering furnace for sintering by a three-stage sintering process. Specifically, the temperature is raised to 650°C at a heating rate of 5°C / min in a vacuum environment, and then held for 45 min. Then, the temperature is raised to 1000°C at a heating rate of 15°C / min, and then held for 25 min. Finally, argon gas is introduced, and the sintering furnace pressure is controlled at 40 MPa. The temperature is raised to 1300°C at a heating rate of 5°C / min, and then held for 10 min. After cooling, a high-entropy dual-phase metal ceramic tool material is obtained.

[0034] Example 2:

[0035] (1) 15 mmol of 5-hydroxyisophthalaldehyde and 42 mmol of carbamate guanidine bicarbonate are added to 80 mL of ethanol, 3 mL of a 37% hydrochloric acid solution is added dropwise, heated to 75°C, and condensed refluxed for 5 h. After distillation under reduced pressure, the product is added to a saturated sodium bicarbonate aqueous solution, extracted with ethyl acetate, and the organic phase is distilled under reduced pressure. The product is recrystallized in ethanol to obtain 5-hydroxyisophthalaldehyde carbamate guanidine.

[0036] (2) 200 mg of graphene oxide is added to 200 mL of N,N-dimethylformamide, ultrasonically dispersed, and then 80 mg of 5-hydroxyisophthalaldehyde carbamate guanidine, 74 mg of 4-dimethylaminopyridine, and 17 mg of dicyclohexyl carbodiimide are added. The mixture is stirred at 60°C for 18 h, filtered, washed with water and ethanol, and dried to obtain guanidine graphene.

[0037] (3) 467 g of Ti powder, 360 g of V powder, 150 g of Nb powder, 18 g of Zr powder, and 5 g of Hf powder were ball-mixed and placed in a sintering furnace, heated to 1100°C at a heating rate of 10°C / min in a nitrogen atmosphere, and sintered for 1.5 h, with the sintering furnace pressure controlled at 30 MPa. After cooling, the mixture was ball-milled to obtain a high-entropy ceramic phase powder.

[0038] (4) A chemical plating solution was prepared by adding 33 g of ferrous sulfate, 14 g of cobalt sulfate, 22 g / L of nickel sulfate, and 27 g / L of sodium phosphite to 1 L of deionized water. Then, 3 kg of the high-entropy ceramic phase powder was added, heated to 75°C, and stirred for 90 min. After filtration, washing, and drying, a high-entropy ceramic phase metal powder with a core-shell structure was obtained.

[0039] (5) 400 g of a high-entropy alloy phase powder composed of Fe powder, Co powder, Ni powder, Cr powder, and Mn powder in a mass ratio of 47:16:25:9:3, 600 g of a high-entropy ceramic phase metal powder with a core-shell structure, and 15 g of guanidyl graphene were ball-mixed for 30 min, and then placed in a sintering furnace for sintering using a three-stage sintering process. Specifically, the temperature was raised to 700°C at a heating rate of 10°C / min in a vacuum environment, and held for 30 min. Then, the temperature was raised to 1100°C at a heating rate of 15°C / min, and held for 20 min. Finally, argon was introduced, and the pressure in the sintering furnace was controlled at 50 MPa. The temperature was raised to 1200°C at a heating rate of 3°C / min, and held for 20 min. After cooling, a high-entropy dual-phase metal ceramic tool material was obtained.

[0040] Example 3:

[0041] (1) 200 mg of graphene oxide was added to 200 mL of N,N-dimethylformamide, and after ultrasonic dispersion, 120 mg of 5-hydroxyisophthalaldehyde guanidine (prepared in Example 1), 116 mg of 4-dimethylaminopyridine, and 26 mg of dicyclohexyl carbodiimide were added. The mixture was stirred at 50°C for 36 h, filtered, washed with water and ethanol, and dried to obtain guanidyl graphene.

[0042] (2) 539 g of Ti powder, 223 g of V powder, 186 g of Nb powder, 40 g of Zr powder, and 12 g of Hf powder were ball-mixed and placed in a sintering furnace, heated to 1300°C at a heating rate of 15°C / min in an argon atmosphere, and sintered for 1 h, with the sintering furnace pressure controlled at 30 MPa. After cooling, the mixture was ball-milled to obtain a high-entropy ceramic phase powder.

[0043] (3) To 1 L of deionized water, 20 g of ferrous sulfate, 8 g of cobalt sulfate, 14 g / L of nickel sulfate, and 17 g / L of sodium phosphite were added to configure a chemical plating solution, 2 kg of high-entropy ceramic phase powder was added, heated to 80°C, stirred for 60 min, filtered, washed with water, and dried to obtain a high-entropy ceramic phase metal powder with a core-shell structure.

[0044] (4) 700 g of high-entropy alloy phase powder composed of Fe powder, Co powder, Ni powder, Cr powder, and Mn powder with a mass ratio of 55:17:16:5:7, 300 g of high-entropy ceramic phase metal powder with a core-shell structure, and 20 g of guanidyl graphene were ball-milled for 60 min, and then placed in a sintering furnace for sintering using a three-stage sintering process, specifically: in a vacuum environment, heated to 600°C at a heating rate of 5°C / min, and held for 45 min, then heated to 1000°C at a heating rate of 10°C / min, and held for 15 min; finally, argon was introduced, and the pressure in the sintering furnace was controlled at 30 MPa, heated to 1400°C at a heating rate of 5°C / min, and held for 10 min, and then cooled to obtain a high-entropy dual-phase metal ceramic tool material.

[0045] Example 4:

[0046] (1) To 150 mL of N,N-dimethylformamide, 200 mg of graphene oxide was added, ultrasonically dispersed, and then 50 mg of 5-hydroxyisophthalaldehyde guanidine (prepared in Example 1), 46 mg of 4-dimethylaminopyridine, and 10 mg of dicyclohexyl carbodiimide were added, and stirred at 45°C for 36 h, filtered, washed with water and ethanol, and dried to obtain guanidyl graphene.

[0047] (2) 493 g of Ti powder, 335 g of V powder, 150 g of Nb powder, 10 g of Zr powder, and 12 g of Hf powder were ball-milled and placed in a sintering furnace, heated to 1200°C at a heating rate of 10°C / min in an argon atmosphere, sintered for 1.5 h, and then cooled and ball-milled to obtain high-entropy ceramic phase powder.

[0048] (3) To 1 L of deionized water, 27 g of ferrous sulfate, 11 g of cobalt sulfate, 18 g / L of nickel sulfate, and 22 g / L of sodium phosphite were added to configure a chemical plating solution, 3 kg of high-entropy ceramic phase powder was added, heated to 75°C, stirred for 90 min, filtered, washed with water, and dried to obtain a high-entropy ceramic phase metal powder with a core-shell structure.

[0049] (4) 500 g of high-entropy alloy phase powder composed of Fe powder, Co powder, Ni powder, Cr powder, and Mn powder with a mass ratio of 54:13:23:4:6, and 500 g of high-entropy ceramic phase metal powder with a core-shell structure, 10 g of guanidyl graphene, were ball-milled for 60 min, and then placed in a sintering furnace. A three-stage sintering process was used for sintering, specifically: in a vacuum environment, the temperature was raised to 600°C at a rate of 10°C / min, and held for 45 min. Then, the temperature was raised to 1000°C at a rate of 10°C / min, and held for 15 min. Finally, argon was introduced, and the pressure in the sintering furnace was controlled at 40 MPa. The temperature was raised to 1300°C at a rate of 5°C / min, and held for 10 min. After cooling, a high-entropy dual-phase metal ceramic tooling material was obtained.

[0050] Comparative Example 1, the difference between this comparative example 1 and Example 1 is that graphene oxide is used instead of guanidyl graphene.

[0051] (1) 600 g of high-entropy alloy phase powder composed of Fe powder, Co powder, Ni powder, Cr powder, and Mn powder with a mass ratio of 49:20:18:9:4, and 400 g of high-entropy ceramic phase metal powder with a core-shell structure (prepared according to Example 1), 5 g of graphene oxide, were ball-milled for 60 min, and then placed in a sintering furnace. A three-stage sintering process was used for sintering, specifically: in a vacuum environment, the temperature was raised to 650°C at a rate of 5°C / min, and held for 45 min. Then, the temperature was raised to 1000°C at a rate of 15°C / min, and held for 25 min. Finally, argon was introduced, and the pressure in the sintering furnace was controlled at 40 MPa. The temperature was raised to 1300°C at a rate of 5°C / min, and held for 10 min. After cooling, a high-entropy dual-phase metal ceramic tooling material was obtained.

[0052] Comparative Example 2, the difference between this comparative example 1 and Example 1 is that 4-hydroxybenzaldehyde guanidine is used instead of 5-hydroxyisophthalaldehyde guanidine.

[0053] (1) 15 mmol of 4-hydroxybenzaldehyde, 18 mmol of guanidine bicarbonate, and 2 mL of a 30% hydrochloric acid solution were added to 60 mL of ethanol. The mixture was heated to 65°C and refluxed for 7 h. The product was distilled under reduced pressure, added to saturated sodium bicarbonate aqueous solution, and extracted with ethyl acetate. The organic phase was distilled under reduced pressure, and the product was recrystallized in ethanol to obtain 4-hydroxybenzaldehyde guanidine. The structural formula is

[0054]

[0055] (2) Into 150 mL of N,N-dimethylformamide, 200 mg of graphene oxide was added, after ultrasonic dispersion, 20 mg of 4-hydroxybenzaldehyde guanidine, 18 mg of 4-dimethylamino pyridine, 4 mg of dicyclohexyl carbodiimide were added, and stirred at 45°C for 24 h, and then filtered, washed with water and ethanol, and dried to obtain guanidine graphene.

[0056] (3) 600 g of high-entropy alloy phase powder composed of Fe powder, Co powder, Ni powder, Cr powder, and Mn powder with a mass ratio of 49:20:18:9:4, and 400 g of core-shell structured high-entropy ceramic phase metal powder (prepared in Example 1), 5 g of guanidine graphene were ball-mixed for 60 min, and then placed in a sintering furnace, and sintered by a three-stage sintering process, specifically: in a vacuum environment, at a heating rate of 5°C / min, heated to 650°C, and kept for 45 min, then at a heating rate of 15°C / min, heated to 1000°C, and kept for 25 min; finally, argon was introduced, and the pressure in the sintering furnace was controlled at 40 MPa, at a heating rate of 5°C / min, heated to 1300°C, and kept for 10 min, and then cooled to obtain a high-entropy dual-phase metal ceramic tool material.

[0057] Comparative Example 3, the difference between Comparative Example 1 and Example 1 is that the core-shell structured high-entropy ceramic phase metal powder is replaced by high-entropy ceramic phase powder.

[0058] (1) 522 g of Ti powder, 276 g of V powder, 180 g of Nb powder, 15 g of Zr powder, and 7 g of Hf powder were ball-mixed, placed in a sintering furnace, and heated to 1200°C at a heating rate of 10°C / min in an argon atmosphere, and sintered for 1.5 h, and then cooled after ball-milling to obtain high-entropy ceramic phase powder.

[0059] (2) 600 g of high-entropy alloy phase powder composed of Fe powder, Co powder, Ni powder, Cr powder, and Mn powder with a mass ratio of 49:20:18:9:4, and 400 g of high-entropy ceramic phase powder, 5 g of guanidine graphene were ball-mixed for 60 min, and then placed in a sintering furnace, and sintered by a three-stage sintering process, specifically: in a vacuum environment, at a heating rate of 5°C / min, heated to 650°C, and kept for 45 min, then at a heating rate of 15°C / min, heated to 1000°C, and kept for 25 min; finally, argon was introduced, and the pressure in the sintering furnace was controlled at 40 MPa, at a heating rate of 5°C / min, heated to 1300°C, and kept for 10 min, and then cooled to obtain a high-entropy dual-phase metal ceramic tool material.

[0060] Comparative Example 4, a three-stage sintering process is not used.

[0061] (1) 600 g of high-entropy alloy phase powder composed of Fe powder, Co powder, Ni powder, Cr powder, and Mn powder with a mass ratio of 49:20:18:9:4, 400 g of core-shell structured high-entropy ceramic phase metal powder (prepared in Example 1), and 5 g of guanidyl graphene (prepared in Example 1) were ball-milled for 60 min, and then placed in a sintering furnace, argon was introduced, and the pressure in the sintering furnace was controlled to be 40 MPa. The temperature was raised to 1300°C at a rate of 5°C / min, and the temperature was maintained for 10 min. After cooling, a high-entropy dual-phase cermet tool material was obtained.

[0062] The compressive strength of the material was tested according to the standard GB / T 23370-2009. The Rockwell hardness was tested according to the standard GB / T 3849.1-2015. The fracture toughness was tested according to the standard GB / T 21143-2014.

[0063] Table 1 Performance test of the material

[0064]

[0065] After testing, the materials of Examples 1-4 have higher compressive strength, Rockwell hardness, and fracture toughness, mainly because the iron-cobalt-nickel alloy layer is formed on the surface of the high-entropy ceramic phase metal powder by chemical plating, forming a unique core-shell structure, improving the interfacial compatibility between the high-entropy ceramic phase metal powder and the Fe-Co-Ni-Cr-Mn high-entropy alloy phase powder, promoting element diffusion and interfacial bonding during sintering, helping to solve the problem of sintering densification of high-entropy materials, thereby improving the internal density and mechanical properties of the material, and the guanidyl graphene added on the surface contains a large number of Schiff base guanidyl groups The iron-cobalt-nickel alloy layer is formed on the surface of the high-entropy ceramic phase metal powder, and the iron-cobalt-nickel and other metal elements in the high-entropy alloy phase powder form a strong chemical coordination effect, thereby improving the interfacial strength between graphene and high-entropy ceramic phase metal powder and high-entropy alloy phase powder, and better promoting the formation of cermet carbide reinforcing phase during high-temperature sintering, further improving the mechanical strength of the material, and adopting a three-stage sintering process, the physical and chemical changes at different temperature stages are reasonable control of the heating rate and the sintering time, improve the sintering efficiency and the density of the material, make the material show higher compressive strength, Rockwell hardness and fracture toughness.

[0066] Comparative Example 1 added ordinary graphene oxide, which has weak chemical coordination effect and low interfacial strength between high-entropy ceramic phase metal powder and high-entropy alloy phase powder, and poor reinforcing effect, resulting in lower compressive strength, Rockwell hardness, and fracture toughness of the material than Example 1.

[0067] The 4-hydroxybenzaldehyde guanidine of the comparative example 2 only contains one Schiff base guanidine group, which results in that the content of the Schiff base guanidine group of the guanidine group graphene prepared is less than that of the guanidine group graphene of the example 1, the chemical coordination and the interface strength between the high-entropy ceramic phase metal powder and the high-entropy alloy phase powder are lower than those of the example 1, the enhancement of the graphene is not good, and the compression strength, the Rockwell hardness and the fracture toughness of the material are lower than those of the example 1.

[0068] The high-entropy ceramic phase powder of the comparative example 3 is not subjected to the iron-cobalt-nickel chemical plating, no core-shell structure is formed, and the interface compatibility between the high-entropy alloy phase powder is not improved, so that the mechanical properties of the material are lower than those of the example 1.

[0069] The three-stage sintering process is not used in the comparative example 4, and the mechanical properties of the material are lower than those of the example 1.

[0070] The above only describes the preferred embodiments of the present application and is not used to limit the present application. The present application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A high entropy dual-phase metal ceramic tool and die material, characterized in that: The raw materials of the high entropy dual-phase metal ceramic tool and die material include 30-60 parts by weight of high entropy ceramic phase metal powder, 40-70 parts by weight of high entropy alloy phase powder, and 0.5-2 parts by weight of guanidine-based graphene; The preparation method of the high entropy ceramic phase metal powder is: (1) Ti powder, V powder, Nb powder, Zr powder, and Hf powder are ball-milled and mixed, placed in a sintering furnace, sintered in an inert atmosphere, and ball-milled after cooling to obtain a high-entropy ceramic phase powder; (2) adding ferrous sulfate, cobalt sulfate, nickel sulfate, and sodium phosphite to deionized water to prepare a chemical plating solution, adding high-entropy ceramic phase powder, stirring the reaction, filtering, washing with water, and drying to obtain high-entropy ceramic phase metal powder; The preparation method of the guanidine-based graphene comprises the following steps: adding graphene oxide to N,N-dimethylformamide, adding 5-hydroxyisophthalaldehyde aminoguanidine, 4-dimethylaminopyridine, and dicyclohexylcarbodiimide after ultrasonic dispersion, stirring for reaction, filtering, washing the filter cake with water and ethanol, and drying to obtain the guanidine-based graphene; The high entropy alloy phase powder includes any one or a combination of Fe powder, Co powder, Ni powder, Cr powder, and Mn powder.

2. The high entropy dual-phase metal ceramic tool and die material according to claim 1, characterized in that: The mass ratio of Ti powder, V powder, Nb powder, Zr powder and Hf powder in (1) is (46-54):(22-36):(15-22):(1-4):(0.5-1.2).

3. The high entropy dual-phase metal ceramic tool and die material according to claim 1, characterized in that: In the above-mentioned (1), the inert atmosphere is nitrogen or argon, the pressure in the sintering furnace is 30-40 MPa, the sintering temperature is 1100-1300° C., and the sintering time is 1-1.5 h.

4. The high entropy dual-phase metal ceramic tool and die material according to claim 1, characterized in that: In the chemical plating solution of (2), the concentration of ferrous sulfate is 14-33 g / L, the concentration of cobalt sulfate is 6-14 g / L, the concentration of nickel sulfate is 10-22 g / L, and the concentration of sodium phosphite is 11-27 g / L.

5. The high entropy dual-phase metal ceramic tool and die material according to claim 1, characterized in that: The reaction temperature in (2) is 75-90° C., and the reaction time is 60-90 min.

6. The high entropy dual-phase metal ceramic tool and die material according to claim 1, characterized in that: In the preparation method of the guanidine-based graphene, the reaction temperature is 45-60° C. and the reaction time is 18-36 hours.

7. The high entropy dual-phase metal ceramic tool and die material according to claim 1, characterized in that: The mass ratio of the graphene oxide, 5-hydroxyisophthalaldehyde aminoguanidine, 4-dimethylaminopyridine and dicyclohexylcarbodiimide is 100:(10-60):(9-58):(2-13).

8. The high entropy dual-phase metal ceramic tool and die material according to claim 7, characterized in that: The preparation method of the 5-hydroxyisophthalaldehyde aminoguanidine comprises the following steps: adding 5-hydroxyisophthalaldehyde and bicarbonate aminoguanidine at a molar ratio of 1:(2.4-2.8) to ethanol, dropwise adding a hydrochloric acid solution having a mass fraction of 30-37%, heating to 65-75° C., condensing and refluxing for 5-7 hours, performing vacuum distillation, adding the product to a saturated sodium bicarbonate aqueous solution, extracting with ethyl acetate, vacuum distilling the organic phase, and recrystallizing the product from ethanol to obtain the 5-hydroxyisophthalaldehyde aminoguanidine.

9. The high entropy dual-phase metal ceramic tool and die material according to claim 1, characterized in that: The mass ratio of Fe powder, Co powder, Ni powder, Cr powder and Mn powder in the high entropy alloy phase powder is (47-55):(13-20):(16-25):(4-9):(3-7).

10. A method for preparing the high entropy dual-phase metal ceramic tool and die material according to any one of claims 1 to 9, characterized in that: The preparation method comprises: ball-milling and mixing high-entropy alloy phase powder, high-entropy ceramic phase metal powder, and guanidine-based graphene, then placing the mixture in a sintering furnace, heating the mixture to 600-700°C at a heating rate of 5-10°C / min under a vacuum environment, and keeping the temperature for 30-45 minutes; then heating the mixture to 1000-1100°C at a heating rate of 10-15°C / min, and keeping the temperature for 15-25 minutes; finally, introducing argon gas, controlling the pressure in the sintering furnace to 30-50 MPa, heating the mixture to 1200-1400°C at a heating rate of 3-5°C / min, keeping the temperature for 10-20 minutes, and cooling the mixture to obtain a high-entropy dual-phase metal ceramic tool and mold material.

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