A high-strength cemented carbide tool substrate material and its preparation method

Abstract

The present invention relates to the technical field of cemented carbide cutting tools, and specifically discloses a high-strength cemented carbide cutting tool matrix material and a preparation method thereof, comprising the following steps: treating tungsten carbide with a nickel precursor solution to obtain nickel-coated tungsten carbide; mixing the nickel-coated tungsten carbide, lanthanum powder, and chromium carbide powder to obtain a composite powder; treating the composite powder with MXene material to obtain a modified composite powder; mixing the modified composite powder, molybdenum powder, and tantalum nitride to obtain a premix; forming the premix into a green compact by dry pressing, and then performing cold isostatic pressing treatment to form a blank, and finally obtaining cemented carbide by microwave sintering; spraying a functional coating on the surface of the cemented carbide, performing heat treatment, and curing to obtain a high-strength cemented carbide cutting tool matrix material. The high-strength cemented carbide cutting tool matrix material of the present invention has excellent mechanical properties, wear resistance, and corrosion resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of cemented carbide tools, and more specifically, to a high-strength cemented carbide tool substrate material and a preparation method thereof. Background Art

[0002] Cemented carbide is an alloy material made by powder metallurgy process from refractory metal hard compounds and binder metals. Due to its advantages such as high strength, high hardness and good wear resistance, cemented carbide is widely used in many fields such as tool manufacturing, die industry and parts processing.

[0003] Compared with other binder metals, nickel-based materials have attracted wide attention due to their excellent fatigue resistance, higher corrosion resistance and higher high-temperature resistance. For example, Chinese Patent CN113584338B discloses a tungsten carbide-based composite material and a preparation method thereof. The method uses tungsten carbide and metal phase as raw materials, and is formulated according to the metal phase mass fraction in the tungsten carbide-based composite material being 1-6wt%. Among them, the metal phase is metal nickel or metal cobalt; the prepared raw materials are added to a ball mill for ball milling to make the tungsten carbide and the metal phase fully mixed and uniform; the mixed material is pressed into a block under a pressure of 20-40 Mpa and placed in a graphite mold; the graphite mold is placed in a vacuum hot press furnace and prepared by vacuum hot pressing sintering to obtain a tungsten carbide-based composite material. The prepared material has good toughness and excellent comprehensive performance. However, the low wettability of Ni on the WC surface and the low solubility of WC in Ni reduce the sinterability and mechanical properties of the sintered cemented carbide, resulting in poor mechanical properties, insufficient wear resistance and general corrosion resistance of WC-Ni cemented carbide compared with WC-Co cemented carbide. Summary of the Invention

[0004] In order to solve the problems mentioned in the above background art, the present invention provides a high-strength cemented carbide tool substrate material and a preparation method thereof. The specific technical solutions are as follows:

[0005] A preparation method of a high-strength cemented carbide tool substrate material includes the following steps:

[0006] Step S1, treating tungsten carbide with a nickel precursor solution to obtain nickel-coated tungsten carbide;

[0007] Step S2, adding nickel-coated tungsten carbide, lanthanum powder, and chromium carbide powder into absolute ethanol, ball milling, drying, grinding, and sieving to obtain a composite powder;

[0008] Step S3, treating the composite powder with MXene material, and adopting ball milling combined with surfactant-assisted hydrothermal method to obtain a modified composite powder;

[0009] Step S4: Add the modified composite powder, molybdenum powder, and tantalum nitride into absolute ethanol, ball mill, dry, grind, and sieve to obtain a premix.

[0010] Step S5: Make the premix into a green compact by dry pressing, then perform cold isostatic pressing to form a blank, and finally obtain the cemented carbide through microwave sintering.

[0011] Step S6: Spray the functionalized coating on the surface of the cemented carbide, perform heat treatment and curing to obtain the high-strength cemented carbide tool substrate material.

[0012] Preferably, the functionalized coating is first prepared by a precipitation reaction of zinc sulfate heptahydrate and ammonium bicarbonate to obtain basic zinc carbonate, then coated with aluminum hydroxide obtained by hydrolysis of ammonium aluminum sulfate, thermally decomposed to obtain a modifier, and then complexed with dopamine and aluminum nitrate nonahydrate to obtain a functionalized filler, and finally crosslinked with hydroxypropyl-terminated polydimethylsiloxane.

[0013] Preferably, in step S1, the nickel-coated tungsten carbide is specifically prepared by the following steps:

[0014] Add the nickel precursor solution to the tungsten carbide powder, first evaporate, and then place it in an argon atmosphere and heat it to 480 - 520 °C at a heating rate of 5 - 10 °C / min to obtain nickel-coated tungsten carbide, wherein the nickel content in the nickel-coated tungsten carbide is 12 - 16 wt%; the nickel precursor solution is obtained by mixing nickel nitrate hexahydrate, nickel acetate tetrahydrate, triethanolamine, and modified silica sol in a mass ratio of (8.5 - 9.5):1:(0.3 - 0.5):(2.8 - 3.4).

[0015] Preferably, in step S2, the mass ratio of the nickel-coated tungsten carbide, lanthanum powder, and chromium carbide powder is (83 - 84):(0.12 - 0.16):(0.8 - 1.2); drying conditions: dry at 76 - 84 °C for 3 - 4 h; sieve mesh number: 200 - 220 mesh; ball milling conditions: ball-to-material ratio is (3 - 5):1, solid-to-liquid ratio is 1:(4 - 8), ball rotation speed is 40 - 50 rpm, ball milling time is 48 - 68 h, and grinding time is 12 - 20 min.

[0016] Preferably, in step S3, the modified composite powder is specifically prepared by the following steps:

[0017] Add cetyltrimethylammonium bromide and composite powder into deionized water, stir evenly at room temperature, then add MXene material, continue to stir for 60 - 90 min, then dropwise add ammonia water, control to finish dropping within 10 min. After dropping, continue to stir and react for 20 - 40 min, raise the temperature to 170 - 180 °C and stir and react for 22 - 26 h, cool to room temperature, filter, centrifuge, wash, and dry to obtain the modified composite powder. Among them, the mass ratio of cetyltrimethylammonium bromide, composite powder, deionized water, MXene material, and ammonia water is (7.6 - 12.8):(9 - 16):(320 - 460):(0.08 - 0.14):(5 - 10).

[0018] Preferably, the mass fraction of the ammonia water is 0.6 - 0.8%.

[0019] Preferably, in the step S4, the mass ratio of the modified composite powder, molybdenum powder, and tantalum nitride is (84 - 86):0.8:(1.2 - 2.2); drying condition: dry at 80 - 90 °C for 2.6 - 3.2 h; grinding time is 8 - 16 min; ball milling condition: ball milling speed is 240 - 320 rpm, ball milling time is 2 - 3 h, ball - to - material ratio is (6 - 8):1, solid - to - liquid ratio is 1:(5 - 7).

[0020] Preferably, in the step S5, the cold isostatic pressing method is specifically: raise the pressure to 200 - 300 MPa within 3 - 5 min, and keep the pressure for 3 - 5 min.

[0021] Preferably, in the step S5, the microwave sintering is specifically: in an argon atmosphere, raise the temperature from room temperature to 920 - 1060 °C at a heating rate of 3 - 5 °C / min, and keep the temperature for 12 - 18 min, then raise the temperature to 1420 - 1500 °C at a heating rate of 15 - 20 °C / min and keep the temperature for 12 - 16 min, and then cool naturally to room temperature.

[0022] Preferably, in the step S6, the spraying thickness of the functionalized coating is 100 - 120 µm; heat treatment method: heat - treat at 120 - 130 °C and 160 - 180 °C for 60 - 80 min successively.

[0023] Preferably, the MXene material is prepared by the following steps:

[0024] Immerse aluminum carbide-titanium powder in a hydrofluoric acid solution, seal it, place it in a ventilated environment, heat it to 35-45 °C, stir and react for 18-24 h. After the reaction, cool it to room temperature, remove the supernatant, wash, dry, grind and sieve it, and then place it in hydrofluoric acid and stir for 24-48 h to obtain the MXene material. Among them, the mass ratio of aluminum carbide-titanium powder, hydrofluoric acid solution and hydrofluoric acid is (1-2):(20-30):(10-14). During the above reaction process, the MXene material is prepared through an etching-stripping-purification process.

[0025] Preferably, the mass fraction of the hydrofluoric acid solution is 35-45%.

[0026] Preferably, the modified silica sol is prepared by the following steps:

[0027] Mix tetraethyl orthosilicate and absolute ethanol, adjust the pH value to 4-5 while stirring at 30-40 °C, react for 2-4 h, add an aluminum dihydrogen phosphate solution, and stir and react at 50-70 °C for 4-6 h to obtain the modified silica sol. Among them, the mass ratio of tetraethyl orthosilicate, absolute ethanol and aluminum dihydrogen phosphate solution is (16-18):(5.5-6.5):(14-16). During the above reaction process, absolute ethanol is the solvent, and aluminum dihydrogen phosphate can catalyze the hydrolysis and condensation reaction of tetraethyl orthosilicate to obtain the modified silica sol.

[0028] Preferably, the mass fraction of the aluminum dihydrogen phosphate solution is 32-36%.

[0029] Preferably, the preparation method of the functionalized coating includes the following steps:

[0030] Step A1: Dissolve zinc sulfate heptahydrate in deionized water, add an aqueous ammonium bicarbonate solution, and dropwise add a mixed solution a of ammonium aluminum sulfate and deionized water while stirring, and control to finish dropping within 15 min. After dropping, heat it to 54-60 °C and stir and react for 0.4-0.6 h, filter, wash and dry to obtain the modifier. Among them, the mass ratio of zinc sulfate heptahydrate, deionized water, aqueous ammonium bicarbonate solution and mixed solution a is (60-70):300:(290-300):(70-80). In the mixed solution a, the mass ratio of ammonium aluminum sulfate and deionized water is 1:(8-9), and the mass fraction of the aqueous ammonium bicarbonate solution is 13.2-13.6%. During the above process, the aluminum hydroxide colloid obtained by the hydrolysis of ammonium aluminum sulfate has a large specific surface area and strong adsorption ability, and can interact with the surface of zinc oxide to form a stable coating structure, and a modifier with aluminum hydroxide coated on the surface is obtained;

[0031] Step A2: Ultrasonically disperse the modifier in Tris-HC1 buffer solution with a pH of 8-9, then add dopamine and stir for 3-5 h. Then add aluminum nitrate nonahydrate and continue to stir for 3.5-4.5 h. After centrifugation and washing, functionalized filler is obtained. The mass ratio of the modifier, Tris-HC1 buffer solution, dopamine and aluminum nitrate nonahydrate is (2-3):(45-55):(0.7-1.1):(0.2-0.5);

[0032] Step A3: Add aluminum dihydrogen phosphate and the functionalized filler into anhydrous DMF, heat up to 55-65 °C and stir evenly. Then dropwise add the mixed solution b of hydroxypropyl-terminated polydimethylsiloxane and toluene, and control the dropping to be completed within 15 min. After dropping, heat up to 75-85 °C and continue to stir for 12-16 min to obtain the functionalized coating. The mass ratio of aluminum dihydrogen phosphate, the functionalized filler, anhydrous DMF and the mixed solution b is (35-45):(6-10):(80-100):(16-22). In the mixed solution b, the mass ratio of hydroxypropyl-terminated polydimethylsiloxane and toluene is (3-5):20.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The present invention starts from two aspects: optimizing the components of the alloy and coating with a functionalized coating, combining internal and external factors to obtain a cemented carbide tool substrate material with excellent wear resistance, corrosion resistance and toughness. Specifically:

[0035] 1. During the alloy preparation process, nano-nickel is deposited and coated on the surface of tungsten carbide by the solution method combined with modified silica sol. At the same time, the hydroxyl groups of silica nanoparticles in the silica sol and the phosphate groups on the surface of aluminum dihydrogen phosphate can serve as anchoring groups to bind nano-nickel through multi-point adsorption, forming uniform nucleation sites. Aluminum dihydrogen phosphate can also catalyze the hydrolysis and condensation reaction of tetraethyl orthosilicate, improving the deposition effect of nano-nickel. Compared with the traditional method of directly adding nickel, it can improve the poor wettability of nickel on the surface of tungsten carbide, making the nickel in the bonding phase evenly distributed on the surface of tungsten carbide, improving the sinterability of nickel-coated tungsten carbide, and increasing the density of the alloy. While maintaining the toughness of the alloy, it improves the hardness and corrosion resistance of the alloy; the addition of lanthanum metal powder reacts with impurities such as oxygen and sulfur in the alloy to form stable compounds, changing the distribution state of impurities, reducing interfacial segregation, increasing the bonding strength of the matrix interface of the alloy, and enhancing mechanical properties and wear resistance; tungsten carbide replaces chromium metal in the traditional process. On the one hand, it can increase the carbon content in the raw materials, prevent the decarburization effect of oxygen in rare earth oxides on cemented carbide, and prevent problems such as product cracking during sintering, ensuring the structural stability of the alloy, thus ensuring the original bending strength and corrosion resistance of the alloy. On the other hand, it also prevents the generation of a large amount of nickel-chromium alloy in the alloy from damaging the original structure of the alloy and reducing the performance of the alloy. In addition, the MXene material is prepared by the etching-stripping process. The addition of the MXene material not only significantly inhibits the growth of tungsten carbide grains, and grain refinement helps to improve the hardness and toughness of the alloy, but also the addition of the MXene material can form a dense oxide layer on the surface of the alloy, improving the corrosion resistance of the alloy; in addition, tantalum nitride plays a role in refining grains and precipitation strengthening, increasing the hardness and wear resistance of the alloy; and during the sintering process, tantalum nitride decomposes and reacts with nickel to generate free nitrogen. The generation of free nitrogen can promote grain growth, and together with tantalum nitride and chromium carbide, it prevents the grains from being too small, reasonably adjusting the grain size.

[0036] 2. The present invention covalently links a modifier, dopamine, and hydroxypropyl-terminated polydimethylsiloxane to form an organic-inorganic three-dimensional crosslinked network: the lamellar structure of aluminum hydroxide on the outer layer of the modifier combines with the spherical structure of nano-zinc oxide. The lamellar structure blocks the straight through-holes in the coating and can play a lubricating role. The spherical nano-zinc oxide not only has high hardness but also can further fill the micropores between the coating and the alloy substrate. At the same time, it can form a dense oxide layer on the surface of the alloy substrate, improving the wear resistance and corrosion resistance of the coating; the abundant hydroxyl groups in the organic-inorganic three-dimensional crosslinked network structure enable the coating to directly form a strong binding force with the alloy substrate, improving the adhesion of the coating; in addition, the polydopamine in the present invention can form a stable hydrogen bond interaction with the modifier, improving the dispersibility of the modifier in the functional coating and the binding strength with hydroxypropyl-terminated polydimethylsiloxane, improving the corrosion resistance and wear resistance of the coating; in addition, both polydopamine and alumina are excellent corrosion inhibitors, which can delay or prevent metal corrosion, realizing active anti-corrosion. Combining with the physical barrier and chemical anti-corrosion of hydroxypropyl-terminated polydimethylsiloxane, a better anti-corrosion effect is achieved. Detailed implementation manners

[0037] To make the implementation manners of the present invention easier to understand, the present invention will be described in detail below in conjunction with specific embodiments. These embodiments are only illustrative and are not limited to the application scope of the present invention.

[0038] For those not specifying specific technologies or conditions in the embodiments, they shall be carried out according to the technologies or conditions described in the literature in this field or according to the product specifications. For reagents or instruments not indicating the manufacturer, they are all conventional products that can be obtained through regular channels.

[0039] The aluminum dihydrogen phosphate is the Jinshuo brand liquid industrial-grade aluminum dihydrogen phosphate sold by Zhengzhou Jinshuo Thermal Insulation and Refractory Materials Co., Ltd., and the hydroxypropyl-terminated polydimethylsiloxane is produced by Guangdong Wengjiang Chemical Reagent Co., Ltd., with the CAS number 104780-66-7.

[0040] The present invention will be further described in detail below in conjunction with the embodiments and comparative examples.

[0041] Preparation Examples 1-3 and Comparative Preparation Example 1 provide the preparation methods of the modified silica sol.

[0042] Preparation Example 1

[0043] This preparation example provides a modified silica sol, which is made by the following steps:

[0044] Tetraethyl orthosilicate and absolute ethanol were stirred at 600 rpm for 14 min until homogeneous. The rotation speed was maintained unchanged at 30 °C, and the pH value was adjusted to 4 with 0.6 M hydrochloric acid aqueous solution while stirring. The reaction was carried out for 2 h, and an aluminum dihydrogen phosphate solution with a mass fraction of 32% was added. The reaction was continued with stirring at 50 °C for 4 h to obtain a modified silica sol. Among them, the mass ratio of tetraethyl orthosilicate, absolute ethanol, and aluminum dihydrogen phosphate solution was 16:5.5:14.

[0045] Preparation Example 2

[0046] This preparation example provides a modified silica sol, which is prepared by the following steps:

[0047] Tetraethyl orthosilicate and absolute ethanol were stirred at 650 rpm for 16 min until homogeneous. The rotation speed was maintained unchanged at 35 °C, and the pH value was adjusted to 4.5 with 0.8 M hydrochloric acid aqueous solution while stirring. The reaction was carried out for 3 h, and an aluminum dihydrogen phosphate solution with a mass fraction of 34% was added. The reaction was continued with stirring at 60 °C for 5 h to obtain a modified silica sol. Among them, the mass ratio of tetraethyl orthosilicate, absolute ethanol, and aluminum dihydrogen phosphate solution was 17:6.0:15.

[0048] Preparation Example 3

[0049] This preparation example provides a modified silica sol, which is prepared by the following steps:

[0050] Tetraethyl orthosilicate and absolute ethanol were stirred at 700 rpm for 18 min until homogeneous. The rotation speed was maintained unchanged at 40 °C, and the pH value was adjusted to 5 with 1.0 M hydrochloric acid aqueous solution while stirring. The reaction was carried out for 4 h, and an aluminum dihydrogen phosphate solution with a mass fraction of 36% was added. The reaction was stirred at 70 °C for 6 h to obtain a modified silica sol. Among them, the mass ratio of tetraethyl orthosilicate, absolute ethanol, and aluminum dihydrogen phosphate solution was 18:6.5:16.

[0051] Comparative Preparation Example 1

[0052] This comparative preparation example provides a modified silica sol, which is prepared by the following steps:

[0053] Tetraethyl orthosilicate and absolute ethanol were stirred at 600 rpm for 14 min until homogeneous. The rotation speed was maintained unchanged at 30 °C, and the pH value was adjusted to 4 with 0.6 M hydrochloric acid aqueous solution while stirring. The reaction was carried out for 2 h, and an aqueous solution of silane coupling agent KH-560 with a mass fraction of 32% was added. The reaction was continued with stirring at 50 °C for 4 h to obtain a modified silica sol. Among them, the mass ratio of tetraethyl orthosilicate, absolute ethanol, and aqueous solution of silane coupling agent KH-560 was 16:5.5:14.

[0054] Preparation Examples 4-6 and Comparative Preparation Example 2 provide an MXene material.

[0055] Preparation Example 4

[0056] This preparation example provides an MXene material, which is prepared by the following steps:

[0057] Immerse the aluminum carbonitride powder in a hydrofluoric acid solution with a mass fraction of 35%, seal it, place it in a ventilated environment and heat it to 35°C, stir and react at a rotation speed of 550 rpm for 18 h. After the reaction is completed, cool it to room temperature, remove the supernatant, wash it with deionized water until neutral, dry it to constant weight at 75°C, grind it through a 300-mesh sieve, and then place it in hydrofluoric acid and stir for 24 h to obtain the MXene material. Among them, the mass ratio of the aluminum carbonitride powder, the hydrofluoric acid solution and hydrofluoric acid is 1:20:10.

[0058] Preparation Example 5

[0059] This preparation example provides an MXene material, which is prepared by the following steps:

[0060] Immerse the aluminum carbonitride powder in a hydrofluoric acid solution with a mass fraction of 40%, seal it, place it in a ventilated environment and heat it to 40°C, stir and react at a rotation speed of 600 rpm for 21 h. After the reaction is completed, cool it to room temperature, remove the supernatant, wash it with deionized water until neutral, dry it to constant weight at 80°C, grind it through a 350-mesh sieve, and then place it in hydrofluoric acid and stir for 36 h to obtain the MXene material. Among them, the mass ratio of the aluminum carbonitride powder, the hydrofluoric acid solution and hydrofluoric acid is 1.5:25:12.

[0061] Preparation Example 6

[0062] This preparation example provides an MXene material, which is prepared by the following steps:

[0063] Immerse the aluminum carbonitride powder in a hydrofluoric acid solution with a mass fraction of 45%, seal it, place it in a ventilated environment and heat it to 45°C, stir and react at a rotation speed of 650 rpm for 24 h. After the reaction is completed, cool it to room temperature, remove the supernatant, wash it with deionized water until neutral, dry it to constant weight at 85°C, grind it through a 400-mesh sieve, and then place it in hydrofluoric acid and stir for 48 h to obtain the MXene material. Among them, the mass ratio of the aluminum carbonitride powder, the hydrofluoric acid solution and hydrofluoric acid is 2:30:14.

[0064] Comparative Preparation Example 2

[0065] This comparative preparation example provides an MXene material, which is prepared by the following steps:

[0066] Immerse aluminum carbide-titanium powder in a hydrofluoric acid solution with a mass fraction of 35%, seal it, place it in a ventilated environment, heat it up to 35°C, stir and react at a rotation speed of 550 rpm for 18 h. After the reaction, cool it to room temperature, remove the supernatant, wash it with deionized water until neutral, dry it to a constant weight at 75°C, grind it through a 300-mesh sieve, and then place it in deionized water and stir for 24 h to obtain the MXene material. Among them, the mass ratio of aluminum carbide-titanium powder, hydrofluoric acid solution, and hydrofluoric acid is 1:20:10.

[0067] Preparation Examples 7-9 and Comparative Preparation Examples 3-5 provide a preparation method for a functionalized coating.

[0068] Preparation Example 7

[0069] This preparation example provides a preparation method for a functionalized coating. The preparation method for this functionalized coating includes the following steps:

[0070] Step A1: Dissolve zinc sulfate heptahydrate in deionized water, add an aqueous solution of ammonium bicarbonate, and while stirring, dropwise add a mixed solution a of ammonium aluminum sulfate and deionized water. Control the dropping to be completed within 15 min. After dropping, heat it up to 54°C and stir and react at a rotation speed of 600 rpm for 0.4 h. Filter, wash it 3 times with deionized water, and dry it to a constant weight at 110°C to obtain a modifier. Among them, the mass ratio of zinc sulfate heptahydrate, deionized water, aqueous solution of ammonium bicarbonate, and mixed solution a is 60:300:290:70. In the mixed solution a, the mass ratio of ammonium aluminum sulfate and deionized water is 1:8, and the mass fraction of the aqueous solution of ammonium bicarbonate is 13.2%;

[0071] Step A2: Ultrasonically disperse the modifier in a Tris-HCl buffer solution with a pH of 8. Control the ultrasonic frequency to be 35 kHz and the ultrasonic power to be 550 w, and ultrasonically treat for 22 min. Then add dopamine and stir and react at a rotation speed of 720 rpm for 3 h. Then add aluminum nitrate nonahydrate, maintain the rotation speed unchanged, and continue to stir for 3.5 h. After centrifugation, wash it 3 times with anhydrous ethanol and deionized water in sequence to obtain a functionalized filler. Among them, the mass ratio of the modifier, Tris-HCl buffer solution, dopamine, and aluminum nitrate nonahydrate is 2:45:0.7:0.2;

[0072] Step A3: Add aluminum dihydrogen phosphate and the functionalized filler to anhydrous DMF, heat it up to 55°C, stir at a rotation speed of 700 rpm for 12 min until homogeneous, then dropwise add a mixed solution b of hydroxypropyl-terminated polydimethylsiloxane and toluene. Control the dropping to be completed within 15 min. After dropping, heat it up to 75°C, maintain the rotation speed unchanged, and continue to stir for 12 min to obtain a functionalized coating. Among them, the mass ratio of aluminum dihydrogen phosphate, functionalized filler, anhydrous DMF, and mixed solution b is 35:6:80:16. In the mixed solution b, the mass ratio of hydroxypropyl-terminated polydimethylsiloxane and toluene is 3:20.

[0073] Preparation Example 8

[0074] This preparation example provides a method for preparing a functionalized coating. The method for preparing the functionalized coating includes the following steps:

[0075] Step A1: Dissolve zinc sulfate heptahydrate in deionized water, add an aqueous ammonium bicarbonate solution, and while stirring, dropwise add a mixed solution a of ammonium aluminum sulfate and deionized water. Control to finish dropping within 15 minutes. After dropping, raise the temperature to 57 °C, stir and react at a rotation speed of 650 rpm for 0.4 h, filter, wash 4 times with deionized water, and dry to constant weight at 115 °C to obtain a modifier. Among them, the mass ratio of zinc sulfate heptahydrate, deionized water, aqueous ammonium bicarbonate solution, and mixed solution a is 60:300:290:70. In the mixed solution a, the mass ratio of ammonium aluminum sulfate and deionized water is 1:8, and the mass fraction of the aqueous ammonium bicarbonate solution is 13.4%;

[0076] Step A2: Ultrasonically disperse the modifier in a Tris-HCl buffer solution with a pH of 8.5. Control the ultrasonic frequency to be 40 kHz, the ultrasonic power to be 600 w, and ultrasonicate for 24 minutes. Then add dopamine, stir and react for 4 h, then add aluminum nitrate nonahydrate, and continue to stir for 4.0 h. After centrifugation, wash 4 times with anhydrous ethanol and deionized water in sequence to obtain a functionalized filler. Among them, the mass ratio of the modifier, Tris-HCl buffer solution, dopamine, and aluminum nitrate nonahydrate is 2.5:50:0.9:0.35;

[0077] Step A3: Add aluminum dihydrogen phosphate and the functionalized filler to anhydrous DMF, raise the temperature to 60 °C, stir at a rotation speed of 740 rpm for 26 minutes, then dropwise add a mixed solution b of hydroxypropyl-terminated polydimethylsiloxane and toluene. Control to finish dropping within 15 minutes. After dropping, raise the temperature to 80 °C, maintain the rotation speed unchanged, and continue to stir for 14 minutes to obtain a functionalized coating. Among them, the mass ratio of aluminum dihydrogen phosphate, functionalized filler, anhydrous DMF, and mixed solution b is 40:8:90:19. In the mixed solution b, the mass ratio of hydroxypropyl-terminated polydimethylsiloxane and toluene is 4:20

[0078] Dissolve hydroxypropyl-terminated polydimethylsiloxane in anhydrous ethanol, then add the functionalized filler, raise the temperature to 55 °C, stir at a rotation speed of 740 rpm for 14 minutes to obtain a functionalized coating. Among them, the mass ratio of hydroxypropyl-terminated polydimethylsiloxane, anhydrous ethanol, and functionalized filler is 5:19:0.8.

[0079] Preparation Example 9

[0080] This preparation example provides a method for preparing a functionalized coating. The method for preparing the functionalized coating includes the following steps:

[0081] Step A1: Dissolve zinc sulfate heptahydrate in deionized water, add ammonium bicarbonate aqueous solution, and while stirring, dropwise add the mixed solution a of ammonium aluminum sulfate and deionized water. Control to finish dropping within 15 minutes. After dropping, raise the temperature to 60 °C, stir and react at a rotation speed of 700 rpm for 0.6 h, filter, wash with deionized water 5 times, and dry at 120 °C to constant weight to obtain a modifier. Among them, the mass ratio of zinc sulfate heptahydrate, deionized water, ammonium bicarbonate aqueous solution, and mixed solution a is 70:300:300:80. In the mixed solution a, the mass ratio of ammonium aluminum sulfate and deionized water is 1:9, and the mass fraction of the ammonium bicarbonate aqueous solution is 13.6%;

[0082] Step A2: Ultrasonically disperse the modifier in a Tris-HC1 buffer solution with a pH of 9. Control the ultrasonic frequency to be 45 kHz and the ultrasonic power to be 650 w, and ultrasonicate for 26 min. Then add dopamine, stir and react for 5 h. Then add aluminum nitrate nonahydrate and continue to stir for 4.5 h. After centrifugation, wash with absolute ethanol and deionized water 5 times in sequence to obtain a functionalized filler. Among them, the mass ratio of the modifier, Tris-HC1 buffer solution, dopamine, and aluminum nitrate nonahydrate is 3:55:1.1:0.5;

[0083] Step A3: Add aluminum dihydrogen phosphate and the functionalized filler to anhydrous DMF, raise the temperature to 65 °C, stir at a rotation speed of 780 rpm for 30 min until uniform, then dropwise add the mixed solution b of hydroxypropyl-terminated polydimethylsiloxane and toluene. Control to finish dropping within 15 minutes. After dropping, raise the temperature to 85 °C, keep the rotation speed unchanged, and continue to stir for 16 min to obtain a functionalized coating. Among them, the mass ratio of aluminum dihydrogen phosphate, the functionalized filler, anhydrous DMF, and mixed solution b is 45:10:100:22. In the mixed solution b, the mass ratio of hydroxypropyl-terminated polydimethylsiloxane and toluene is 5:20.

[0084] Comparative Preparation Example 3

[0085] This comparative preparation example provides a preparation method of a functionalized coating. The preparation method of the functionalized coating includes the following steps:

[0086] Step A1: Dissolve copper sulfate in deionized water, add ammonium bicarbonate aqueous solution, and while stirring, dropwise add the mixed solution a of ammonium aluminum sulfate and deionized water. Control to finish dropping within 15 minutes. After dropping, raise the temperature to 54 °C, stir and react at a rotation speed of 600 rpm for 0.4 h, filter, wash with deionized water 3 times, and dry at 110 °C to constant weight to obtain a modifier. Among them, the mass ratio of copper sulfate, deionized water, ammonium bicarbonate aqueous solution, and mixed solution a is 60:300:290:70. In the mixed solution a, the mass ratio of ammonium aluminum sulfate and deionized water is 1:8, and the mass fraction of the ammonium bicarbonate aqueous solution is 13.2%;

[0087] Step A2: Ultrasonically disperse the modifier in Tris-HC1 buffer solution with a pH of 8, control the ultrasonic frequency at 35 kHz, ultrasonic power at 550 w, ultrasonicate for 22 min, then add dopamine, stir and react at a rotation speed of 720 rpm for 3 h, then add aluminum nitrate nonahydrate, maintain the rotation speed unchanged, continue to stir for 3.5 h, centrifuge, and wash 3 times with anhydrous ethanol and deionized water in sequence to obtain the functionalized filler. Among them, the mass ratio of the modifier, Tris-HC1 buffer solution, dopamine, and aluminum nitrate nonahydrate is 2:45:0.7:0.2;

[0088] Step A3: Add aluminum dihydrogen phosphate and the functionalized filler to anhydrous DMF, heat up to 55 °C, stir at a rotation speed of 700 rpm for 12 min until uniform, then dropwise add the mixed solution b of hydroxypropyl-terminated polydimethylsiloxane and toluene, control to finish dropping within 15 min, after dropping, heat up to 75 °C, maintain the rotation speed unchanged, continue to stir for 12 min to obtain the functionalized coating. Among them, the mass ratio of aluminum dihydrogen phosphate, the functionalized filler, anhydrous DMF, and the mixed solution b is 35:6:80:16. In the mixed solution b, the mass ratio of hydroxypropyl-terminated polydimethylsiloxane and toluene is 3:20.

[0089] Comparative Preparation Example 4

[0090] This comparative preparation example provides a preparation method of a functionalized coating. The preparation method of the functionalized coating includes the following steps:

[0091] Step A1: Dissolve zinc sulfate heptahydrate in deionized water, add an aqueous solution of ammonium bicarbonate, dropwise add the mixed solution a of ammonium copper sulfate and deionized water while stirring, control to finish dropping within 15 min, after dropping, heat up to 54 °C, stir and react at a rotation speed of 600 rpm for 0.4 h, filter, wash 3 times with deionized water, and dry at 110 °C to constant weight to obtain the modifier. Among them, the mass ratio of zinc sulfate heptahydrate, deionized water, aqueous solution of ammonium bicarbonate, and the mixed solution a is 60:300:290:70. In the mixed solution a, the mass ratio of ammonium copper sulfate and deionized water is 1:8, and the mass fraction of the aqueous solution of ammonium bicarbonate is 13.2%;

[0092] Step A2: Ultrasonically disperse the modifier in Tris-HC1 buffer solution with a pH of 8, control the ultrasonic frequency at 35 kHz, ultrasonic power at 550 w, ultrasonicate for 22 min, then add dopamine, stir and react at a rotation speed of 720 rpm for 3 h, then add aluminum nitrate nonahydrate, maintain the rotation speed unchanged, continue to stir for 3.5 h, centrifuge, and wash 3 times with anhydrous ethanol and deionized water in sequence to obtain the functionalized filler. Among them, the mass ratio of the modifier, Tris-HC1 buffer solution, dopamine, and aluminum nitrate nonahydrate is 2:45:0.7:0.2;

[0093] Step A3: Add aluminum dihydrogen phosphate and functionalized filler into anhydrous DMF, heat up to 55°C, stir for 12 min at a rotation speed of 700 rpm until homogeneous, then dropwise add the mixed solution b of hydroxypropyl-terminated polydimethylsiloxane and toluene, control to finish dropping within 15 min. After dropping, heat up to 75°C, keep the rotation speed unchanged, and continue to stir for 12 min to obtain the functionalized coating. Among them, the mass ratio of aluminum dihydrogen phosphate, functionalized filler, anhydrous DMF and the mixed solution b is 35:6:80:16. In the mixed solution b, the mass ratio of hydroxypropyl-terminated polydimethylsiloxane and toluene is 3:20.

[0094] Comparative Preparation Example 5

[0095] This comparative preparation example provides a preparation method of a functionalized coating. The preparation method of this functionalized coating includes the following steps:

[0096] Step A1: Dissolve zinc sulfate heptahydrate in deionized water, add an aqueous solution of ammonium bicarbonate, and dropwise add the mixed solution a of ammonium aluminum sulfate and deionized water while stirring, control to finish dropping within 15 min. After dropping, heat up to 54°C, stir and react at a rotation speed of 600 rpm for 0.4 h, filter, wash with deionized water 3 times, and dry at 110°C to constant weight to obtain the modifier. Among them, the mass ratio of zinc sulfate heptahydrate, deionized water, aqueous solution of ammonium bicarbonate and the mixed solution a is 60:300:290:70. In the mixed solution a, the mass ratio of ammonium aluminum sulfate and deionized water is 1:8, and the mass fraction of the aqueous solution of ammonium bicarbonate is 13.2%;

[0097] Step A2: Ultrasonically disperse the modifier in a Tris-HCl buffer solution with a pH of 8, control the ultrasonic frequency to be 35 kHz, the ultrasonic power to be 550 w, and ultrasonically treat for 22 min. Then add dopamine, stir and react at a rotation speed of 720 rpm for 3 h, then add cerium nitrate, keep the rotation speed unchanged, and continue to stir for 3.5 h. After centrifugation, wash with absolute ethanol and deionized water 3 times respectively to obtain the functionalized filler. Among them, the mass ratio of the modifier, Tris-HCl buffer solution, dopamine and cerium nitrate is 2:45:0.7:0.2;

[0098] Step A3: Add aluminum dihydrogen phosphate and functionalized filler into anhydrous DMF, heat up to 55°C, stir for 12 min at a rotation speed of 700 rpm until homogeneous, then dropwise add the mixed solution b of hydroxypropyl-terminated polydimethylsiloxane and toluene, control to finish dropping within 15 min. After dropping, heat up to 75°C, keep the rotation speed unchanged, and continue to stir for 12 min to obtain the functionalized coating. Among them, the mass ratio of aluminum dihydrogen phosphate, functionalized filler, anhydrous DMF and the mixed solution b is 35:6:80:16. In the mixed solution b, the mass ratio of hydroxypropyl-terminated polydimethylsiloxane and toluene is 3:20.

[0099] Examples 1-3 and Comparative Examples 1-5 provide a method for preparing a high-strength cemented carbide tool substrate material.

[0100] Example 1

[0101] This example provides a method for preparing a high-strength cemented carbide tool substrate material, including the following steps:

[0102] Step S1: Add the nickel precursor solution to the tungsten carbide powder, first evaporate it, and then place it in an argon atmosphere. Heat it to 480 °C at a heating rate of 5 °C / min to obtain nickel-coated tungsten carbide, where the nickel content in the nickel-coated tungsten carbide is 12 wt%. The nickel precursor solution is obtained by mixing nickel nitrate hexahydrate, nickel acetate tetrahydrate, triethanolamine, and the modified silica sol prepared in Preparation Example 1 in a mass ratio of 8.5:1:0.3:2.8;

[0103] Step S2: Add the nickel-coated tungsten carbide, lanthanum powder, and chromium carbide powder to anhydrous ethanol, ball mill, control the ball-to-material ratio to be 3:1, the solid-to-liquid ratio to be 1:4, the ball rotation speed to be 40 rpm, and the ball milling time to be 48 h. Then dry it at 76 °C for 3 h, grind it for 12 min, and pass through a 300-mesh sieve to obtain a composite powder, where the mass ratio of the nickel-coated tungsten carbide, lanthanum powder, and chromium carbide powder is 83:0.12:0.8;

[0104] Step S3: Add cetyltrimethylammonium bromide and the composite powder to deionized water, stir at a rotation speed of 600 rpm at room temperature for 12 min until homogeneous, then add the MXene material prepared in Preparation Example 4, maintain the rotation speed unchanged, continue to stir for 60 min, then dropwise add ammonia water with a mass fraction of 0.6%, control to finish dropping within 10 min, after dropping, continue to stir and react for 20 min, heat up to 170 °C and stir and react for 22 h, cool to room temperature, centrifugally separate, wash with deionized water 3 times, and dry at 60 °C to constant weight to obtain a modified composite powder, where the mass ratio of cetyltrimethylammonium bromide, the composite powder, deionized water, the MXene material, and ammonia water is 7.6:9:320:0.08:5;

[0105] Step S4: Add the modified composite powder, molybdenum powder, and tantalum nitride to anhydrous ethanol, ball mill, control the ball milling rotation speed to be 240 rpm, the ball milling time to be 2 h, the ball-to-material ratio to be 6:1, and the solid-to-liquid ratio to be 1:5; dry, and then dry at 80 °C for 2.6 h, grind for 8 min, and pass through a 120-mesh sieve to obtain a premix, where the mass ratio of the modified composite powder, molybdenum powder, and tantalum nitride is 84:0.8:1.2;

[0106] Step S5: The premix is made into a green body by dry pressing, then the pressure is increased to 20 MPa within 3 min and held for 3 min to form a billet. Finally, in an argon atmosphere, it is heated from room temperature to 920 °C at a heating rate of 3 °C / min and held for 12 min, then heated to 1420 °C at a heating rate of 15 °C / min and held for 12 min, and naturally cooled to room temperature to obtain cemented carbide.

[0107] Step S6: The functionalized coating prepared in Preparation Example 7 is sprayed on the surface of the cemented carbide with a spraying thickness of 100 µm, and heat-treated at 120 °C and 160 °C for 60 min successively, and cured to obtain a high-strength cemented carbide tool substrate material.

[0108] Example 2

[0109] This example provides a preparation method of the high-strength cemented carbide tool substrate material, including the following steps:

[0110] Step S1: The nickel precursor solution is added to the tungsten carbide powder, first evaporated, and then placed in an argon atmosphere and heated to 500 °C at a heating rate of 8 °C / min to obtain nickel-coated tungsten carbide, wherein the nickel content in the nickel-coated tungsten carbide is 14 wt%; the nickel precursor solution is obtained by mixing nickel nitrate hexahydrate, nickel acetate tetrahydrate, triethanolamine and the modified silica sol prepared in Preparation Example 2 in a mass ratio of 9.0:1:0.4:3.1.

[0111] Step S2: The nickel-coated tungsten carbide, lanthanum powder, and chromium carbide powder are added to anhydrous ethanol and ball-milled. The ball-to-material ratio is controlled at 4:1, the solid-to-liquid ratio is 1:6, the ball rotation speed is 45 rpm, and the ball-milling time is 58 h. Then it is dried at 80 °C for 3.5 h, ground for 16 min, and sieved through a 320-mesh sieve to obtain a composite powder, wherein the mass ratio of the nickel-coated tungsten carbide, lanthanum powder, and chromium carbide powder is 83.5:0.14:1.0.

[0112] Step S3: Cetyltrimethylammonium bromide and the composite powder are added to deionized water, and stirred at a rotation speed of 640 rpm at room temperature for 16 min until uniform. Then the MXene material prepared in Preparation Example 5 is added, and the rotation speed is maintained unchanged, and stirring is continued for 75 min. Then, ammonia water with a mass fraction of 0.7% is added dropwise, and the addition is controlled to be completed within 10 min. After the addition is completed, stirring reaction is continued for 30 min, and then heated to 175 °C and stirred for reaction for 24 h. It is cooled to room temperature, centrifuged and separated, washed 4 times with deionized water, and dried to constant weight at 65 °C to obtain a modified composite powder, wherein the mass ratio of cetyltrimethylammonium bromide, composite powder, deionized water, MXene material, and ammonia water is 10.2:12.5:390:0.11:7.5.

[0113] Step S4: Add the modified composite powder, molybdenum powder, and tantalum nitride into absolute ethanol, and ball-mill them. Control the ball-milling speed at 280 rpm, the ball-milling time at 2.5 h, the ball-to-material ratio at 7:1, and the solid-to-liquid ratio at 1:6. Then dry them at 85°C for 2.9 h, grind them for 12 min, and pass through a 140-mesh sieve to obtain a premix. Among them, the mass ratio of the modified composite powder, molybdenum powder, and tantalum nitride is 85:0.8:1.7;

[0114] Step S5: Form a green compact by dry pressing the premix, then raise the pressure to 250 MPa within 4 min and hold the pressure for 4 min to form a blank. Finally, in an argon atmosphere, heat it from room temperature to 990°C at a heating rate of 4°C / min and hold for 15 min, then heat it to 1460°C at a heating rate of 18°C / min and hold for 14 min, and naturally cool it to room temperature to obtain cemented carbide;

[0115] Step S6: Spray the functionalized coating prepared in Preparation Example 8 on the surface of the cemented carbide, with a spraying thickness of 110 µm, and heat-treat it at 125°C and 170°C for 70 min successively, and cure it to obtain a high-strength cemented carbide tool substrate material.

[0116] Example 3

[0117] This example provides a preparation method of a high-strength cemented carbide tool substrate material, including the following steps:

[0118] Step S1: Add the nickel precursor solution to the tungsten carbide powder, first evaporate it, and then place it in an argon atmosphere and heat it to 520°C at a heating rate of 10°C / min to obtain nickel-coated tungsten carbide. Among them, the nickel content in the nickel-coated tungsten carbide is 16 wt%; the nickel precursor solution is obtained by mixing nickel nitrate hexahydrate, nickel acetate tetrahydrate, triethanolamine, and the modified silica sol prepared in Preparation Example 3 in a mass ratio of 9.5:1:0.5:3.4;

[0119] Step S2: Add the nickel-coated tungsten carbide, lanthanum powder, and chromium carbide powder into absolute ethanol, and ball-mill them. Control the ball-to-material ratio at 5:1, the solid-to-liquid ratio at 1:8, the ball speed at 50 rpm, and the ball-milling time at 68 h. Then dry them at 84°C for 4 h, grind them for 20 min, and pass through a 340-mesh sieve to obtain a composite powder. Among them, the mass ratio of the nickel-coated tungsten carbide, lanthanum powder, and chromium carbide powder is 84:0.16:1.2;

[0120] Step S3: Add cetyltrimethylammonium bromide and composite powder into deionized water, stir at a rotation speed of 680 rpm at room temperature for 20 min until uniform, then add the MXene material prepared in Preparation Example 6, continue stirring for 90 min, then dropwise add ammonia water with a mass fraction of 0.8%, control to finish dropping within 10 min, after dropping, continue stirring and reacting for 40 min, raise the temperature to 180 °C and stir and react for 26 h, cool to room temperature, filter, perform centrifugal separation, wash with deionized water 5 times, and dry at 70 °C to constant weight to obtain the modified composite powder, wherein the mass ratio of cetyltrimethylammonium bromide, composite powder, deionized water, MXene material, and ammonia water is 12.8:16:460:0.14:10;

[0121] Step S4: Add the modified composite powder, molybdenum powder, and tantalum nitride into absolute ethanol, perform ball milling, control the ball milling rotation speed to be 320 rpm, the ball milling time to be 3 h, the ball-to-material ratio to be 8:1, and the solid-to-liquid ratio to be 1:7, then place it in an oven at 90 °C and dry for 3.2 h, and pass through a 160-mesh sieve to obtain the premix, wherein the mass ratio of the modified composite powder, molybdenum powder, and tantalum nitride is 86:0.8:2.2;

[0122] Step S5: Make the premix into a green compact by dry pressing, then raise the pressure to 300 MPa within 5 min and hold the pressure for 5 min to form a billet, and finally in an argon atmosphere, raise the temperature from room temperature to 1060 °C at a heating rate of 5 °C / min and hold for 18 min, then raise the temperature to 1500 °C at a heating rate of 20 °C / min and hold for 16 min, and naturally cool to room temperature to obtain the cemented carbide;

[0123] Step S6: Spray the functionalized coating prepared in Preparation Example 9 on the surface of the cemented carbide, with a spraying thickness of 120 µm, and perform heat treatment at 130 °C and 180 °C for 80 min successively, and cure to obtain the high-strength cemented carbide tool substrate material.

[0124] Comparative Example 1

[0125] Comparative Example 1 is the same as Example 1, the only difference being that the modified silica sol in Example 1 is replaced with the modified silica sol prepared in Comparative Preparation Example 1.

[0126] Comparative Example 2

[0127] Comparative Example 2 is the same as Example 1, the only difference being that the MXene material in Example 1 is replaced with the modified silica sol prepared in Comparative Preparation Example 2.

[0128] Comparative Example 3

[0129] Comparative Example 3 is the same as Example 1, the only difference being that the functionalized coating in Example 1 is replaced with the functionalized coating prepared in Comparative Preparation Example 3.

[0130] Comparative Example 4

[0131] Comparative Example 4 is the same as Example 1, except that the functionalized coating in Example 1 is replaced with the functionalized coating prepared in Comparative Preparation Example 4.

[0132] Comparative Example 5

[0133] Comparative Example 5 is the same as Example 1, except that the functionalized coating in Example 1 is replaced with the functionalized coating prepared in Comparative Preparation Example 5.

[0134] Performance Test

[0135] The following performance tests were carried out on the cemented carbide tool substrate materials prepared in Examples 1-3 and Comparative Examples 1-5. The thickness of the cemented carbide tool was controlled to be 3 mm;

[0136] Flexural strength: Tested according to GB / T232-2010, and the three-point bending method was used to test the flexural strength;

[0137] Impact resistance: The prepared cemented carbide tool substrate material was used as a cutting tool to cut 42CrMo steel. The cutting speed was 250 m / min, the cutting amount was 2 mm, and the feed rate was 0.5 mm / rev. The machining length completed when obvious chipping or damage and other defects appeared on the cutting tool was used as the evaluation standard, unit, m. The larger the machining length value, the better the impact resistance of the cemented carbide;

[0138] Wear resistance: The prepared cemented carbide tool substrate material was used as a cutting tool to cut 42CrMo steel. The cutting speed was 250 m / min, the cutting amount was 2 mm, and the feed rate was 0.1 mm / rev. The machining length completed when the wear amount of the cutting tool reached 0.1 mm was used as the evaluation standard, unit, m. The larger the machining length value, the better the wear resistance of the cemented carbide;

[0139] Vickers hardness: The room temperature hardness (HV) was tested on a Vickers hardness tester with a load of 30 kg; According to the Nihara formula, the fracture toughness (KIC) was calculated from the radial crack length generated by the Vickers hardness indentation, unit MPa·m1 / 2;

[0140] Corrosion resistance test: An electrochemical workstation (CHI 660E, Shanghai Chenhua Instrument Co., Ltd.) was used to study the corrosion behavior of each group of samples in 3.5% NaCl aqueous solution.

[0141] The corrosion experiment was carried out at room temperature. The working electrode used an Ag / AgCl electrode as the reference electrode and a platinum foil electrode as the counter electrode. In the range of -1.0 - 0.4 V, the scanning speed was 1 mV / s, and the corrosion potential (Ecorr) of the prepared samples was analyzed;

[0142] The specific test results are as follows:

[0143] Table 1 Performance Test Results

[0144]

[0145] Compared with Comparative Examples 1-5, the alloy tool matrix materials prepared in Examples 1-3 have more excellent hardness, wear resistance and toughness.

[0146] The performance data of Example 1 and Comparative Example 1 show that when aluminum dihydrogen phosphate is used to synergistically modify silica sol and introduced into the synthesis system of cemented carbide, the hardness, toughness and corrosion resistance of the alloy are significantly improved; the phosphate groups on the surface of aluminum dihydrogen phosphate can act as anchor groups to adsorb and bind nano-nickel, forming uniform nucleation sites, which can improve the problem of poor wettability of nickel on the surface of tungsten carbide, make the nickel in the binder phase uniformly distributed on the surface of tungsten carbide, improve the sinterability of nickel-coated tungsten carbide, and improve the density of the alloy, while maintaining the toughness of the alloy, improving the hardness and corrosion resistance of the alloy.

[0147] According to the test results of Example 1 and Comparative Example 2, the etching process can endow MXene materials with a larger specific surface area and more active sites, which not only significantly improves the wettability of the alloy interface and the interfacial bonding strength of the material, but also helps to form a dense oxide layer on the alloy surface, improving the corrosion resistance of the alloy.

[0148] According to the comparative analysis of Example 1 and Comparative Example 3, the spherical nano-zinc oxide inside the modifier not only has high hardness itself, but also can further fill the micropores between the coating and the alloy matrix. At the same time, it can form a dense oxide layer on the surface of the alloy matrix, improving the wear resistance and corrosion resistance of the coating.

[0149] According to the test results of Example 1 and Comparative Example 4, the lamellar structure of aluminum hydroxide on the outer layer of the modifier can block the straight through holes in the coating and play a lubricating role, significantly improving the wear resistance and corrosion resistance of the alloy.

[0150] According to the test results of Example 1 and Comparative Example 5, the alumina formed by the thermal curing of aluminum nitrate nonahydrate not only has excellent physical properties itself, but also can act as a corrosion inhibitor, significantly improving the mechanical properties and corrosion resistance of the alloy.

[0151] This specific embodiment is only an explanation of the present invention, and it is not a limitation of the present invention. Those skilled in the art can make modifications to this embodiment without creative contributions according to needs after reading this specification, but as long as it is within the scope of the claims of the present invention, it is protected by the patent law.

Claims

1. A preparation method of a high-strength cemented carbide tool substrate material, characterized in that, It includes the following steps: Step S1: Treat tungsten carbide with a nickel precursor solution to obtain nickel-coated tungsten carbide; Step S2: Add nickel-coated tungsten carbide, lanthanum powder, and chromium carbide powder into absolute ethanol, ball mill, dry, grind, and sieve to obtain a composite powder; Step S3: Treat the composite powder with MXene material by using a method combining ball milling and surfactant-assisted hydrothermal method to obtain a modified composite powder; Step S4: Add the modified composite powder, molybdenum powder, and tantalum nitride into absolute ethanol, ball mill, dry, grind, and sieve to obtain a premix; Step S5: Make the premix into a green compact by dry pressing, then perform cold isostatic pressing treatment to form a blank, and finally obtain a cemented carbide through microwave sintering; Step S6: Spray a functionalized coating on the surface of the cemented carbide, perform heat treatment and curing to obtain a high-strength cemented carbide tool substrate material; The functionalized coating is first obtained by a precipitation reaction of zinc sulfate heptahydrate and ammonium bicarbonate to obtain basic zinc carbonate, then coated with aluminum hydroxide obtained by hydrolysis reaction of ammonium aluminum sulfate, thermally decomposed to obtain a modifier, and then complexed with dopamine and aluminum nitrate nonahydrate to obtain a functionalized filler, and finally crosslinked with hydroxypropyl-terminated polydimethylsiloxane; In the said Step S1, the nickel-coated tungsten carbide is specifically obtained by the following steps: Add the nickel precursor solution into tungsten carbide powder, first evaporate, then place it in an argon atmosphere, heat it to 480 - 520 °C at a heating rate of 5 - 10 °C / min to obtain nickel-coated tungsten carbide, wherein the nickel content in the nickel-coated tungsten carbide is 12 - 16 wt%; the nickel precursor solution is obtained by mixing nickel nitrate hexahydrate, nickel acetate tetrahydrate, triethanolamine, and modified silica sol in a mass ratio of (8.5 - 9.5):1:(0.3 - 0.5):(2.8 - 3.4); The said modified silica sol is made by the following steps: Mix tetraethyl orthosilicate and absolute ethanol, adjust the pH value to 4 - 5 while stirring at 30 - 40 °C, react for 2 - 4 h, add an aluminum dihydrogen phosphate solution, and stir and react at 50 - 70 °C for 4 - 6 h to obtain modified silica sol, wherein the mass ratio of tetraethyl orthosilicate, absolute ethanol, and aluminum dihydrogen phosphate solution is (16 - 18):(5.5 - 6.5):(14 - 16); The said MXene material is obtained by the following steps: Immerse aluminum carbide titanium powder into a hydrofluoric acid solution, seal it, place it in a ventilated environment and heat it to 35 - 45 °C, stir and react for 18 - 24 h. After the reaction ends, cool it to room temperature, remove the upper clear liquid, wash, dry, grind and sieve, and then place it in hydrofluoric acid and stir for 24 - 48 h to obtain MXene material, wherein the mass ratio of aluminum carbide titanium powder, hydrofluoric acid solution, and hydrofluoric acid is (1 - 2):(20 - 30):(10 - 14).

2. The preparation method of a high-strength cemented carbide tool substrate material according to claim 1, characterized in that, In the step S2, the mass ratio of nickel-coated tungsten carbide, lanthanum powder, and chromium carbide powder is (83 - 84):(0.12 - 0.16):(0.8 - 1.2); drying condition: drying at 76 - 84°C for 3 - 4 h; the mesh number for sieving is 200 - 220 meshes; ball milling condition: the ball-to-material ratio is (3 - 5):1, the solid-to-liquid ratio is 1:(4 - 8), the ball rotation speed is 40 - 50 rpm, the ball milling time is 48 - 68 h, and the grinding time is 12 - 20 min.

3. The preparation method of a high-strength cemented carbide tool substrate material according to claim 1, characterized in that, In the step S3, the modified composite powder is specifically prepared by the following steps: Add cetyltrimethylammonium bromide and the composite powder into deionized water, stir evenly at room temperature, then add the MXene material, continue stirring for 60 - 90 min, then dropwise add ammonia water, control to finish dropping within 10 min. After dropping, continue stirring and reacting for 20 - 40 min, raise the temperature to 170 - 180°C and stir and react for 22 - 26 h, cool to room temperature, filter, centrifuge, wash, and dry to obtain the modified composite powder, where the mass ratio of cetyltrimethylammonium bromide, the composite powder, deionized water, the MXene material, and ammonia water is (7.6 - 12.8):(9 - 16):(320 - 460):(0.08 - 0.14):(5 - 10).

4. The preparation method of a high-strength cemented carbide tool substrate material according to claim 3, characterized in that, In the step S4, the mass ratio of the modified composite powder, molybdenum powder, and tantalum nitride is (84 - 86): 0.8:(1.2 - 2.2); drying condition: drying at 80 - 90°C for 2.6 - 3.2 h; the grinding time is 8 - 16 min, and the solid-to-liquid ratio is 1:(5 - 7).

5. The preparation method of a high-strength cemented carbide tool substrate material according to claim 1, characterized in that, In the step S5, the cold isostatic pressing method is specifically as follows: raise the pressure to 200 - 300 MPa within 3 - 5 min, keep the pressure for 3 - 5 min. The microwave sintering is specifically as follows: in an argon atmosphere, raise the temperature from room temperature to 920 - 1060°C at a heating rate of 3 - 5°C / min and keep the temperature for 12 - 18 min, then raise the temperature to 1420 - 1500°C at a heating rate of 15 - 20°C / min and keep the temperature for 12 - 16 min, and naturally cool to room temperature.

6. The preparation method of a high-strength cemented carbide tool substrate material according to claim 1, characterized in that In the step S6, the preparation method of the functionalized coating includes the following steps: Step A1: Dissolve zinc sulfate heptahydrate in deionized water, add an aqueous solution of ammonium bicarbonate, and dropwise add a mixed solution a of ammonium alum and deionized water while stirring, control to finish dropping within 15 min. After dropping, raise the temperature to 54 - 60°C, stir and react for 0.4 - 0.6 h, filter, wash, and dry to obtain the modifier. Step A2: Ultrasonically disperse the modifier in a Tris-HC1 buffer solution with a pH of 8 - 9, then add dopamine, stir and react for 3 - 5 h, then add aluminum nitrate nonahydrate, continue stirring for 3.5 - 4.5 h, and after centrifuging and washing, obtain the functionalized filler. Step A3: Add aluminum dihydrogen phosphate and the functionalized filler into anhydrous DMF, raise the temperature to 55 - 65°C, stir evenly, then dropwise add a mixed solution b of hydroxypropyl-terminated polydimethylsiloxane and toluene, control to finish dropping within 15 min. After dropping, raise the temperature to 75 - 85°C and continue stirring for 12 - 16 min to obtain the functionalized coating.

7. A high-strength cemented carbide tool substrate material prepared by using the preparation method of the high-strength cemented carbide tool substrate material described in any one of claims 1-6.

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