High-temperature-resistant cemented carbide and method for manufacturing the same
By introducing composite additives into tungsten carbide cemented carbide to form a cross-linked carbon network structure, the problem of decreased mechanical properties of tungsten carbide cemented carbide at high temperatures was solved, achieving higher mechanical properties and high-temperature resistance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- PENG TUNGSTEN ALLOY (SHANDONG) CO LTD
- Filing Date
- 2026-05-08
- Publication Date
- 2026-06-05
Smart Images
Figure SMS_1
Abstract
Description
Technical Field
[0001] This invention relates to the field of cemented carbide technology, specifically to a high-temperature resistant cemented carbide and its preparation method. Background Technology
[0002] Hard alloys are composite materials prepared by powder metallurgy, using hard compounds of refractory metals (tungsten carbide, titanium carbide, tantalum carbide, etc.) as the hard phase and transition metal elements (cobalt, nickel, iron, etc.) as the binder phase. They have excellent properties such as high hardness, high strength, high toughness, wear resistance, high temperature resistance and low coefficient of expansion, and are widely used in cutting, drilling, mining, tool forming and wear-resistant parts.
[0003] Tungsten carbide cemented carbide, prepared with tungsten carbide as the hard phase and cobalt, nickel, and iron as the binder phase, has advantages such as high hardness, excellent wear resistance, and good impact fracture toughness. However, when tungsten carbide cemented carbide works in a high-temperature environment for a long time, the heat is difficult to dissipate in the tungsten carbide cemented carbide, which leads to a decrease in the mechanical properties of the tungsten carbide cemented carbide and easy deformation, affecting the service life of the tungsten carbide cemented carbide cemented carbide. Summary of the Invention
[0004] This invention provides a high-temperature resistant cemented carbide and its preparation method, which solves the problem that when tungsten carbide works in a high-temperature environment for a long time, heat is difficult to dissipate, leading to a decline in the mechanical properties of tungsten carbide.
[0005] The technical solution of the present invention: A high-temperature resistant cemented carbide comprises the following raw materials in parts by weight: 80-90 parts tungsten carbide powder, 1.5-2 parts cobalt powder, 2-3 parts nickel powder, 1-2 parts iron powder, 0.5-1 part niobium powder, 0.5-1 part tantalum powder, and 3-5 parts composite additives. The composite additive is obtained by modifying carbon fibers on the surface of carboxymethyl cellulose and then mixing them with composite core-shell particles. The composite core-shell particles are formed by adhering nano-zirconium carbide to the surface of yttrium oxide with tannic acid. After the core-shell particles are modified with aminosilane, they are then mixed and reacted with sulfonated lignin and boric acid.
[0006] A method for preparing a high-temperature resistant cemented carbide includes the following preparation steps: S1. Tungsten carbide powder, cobalt powder, nickel powder, iron powder, niobium powder, tantalum powder and composite additives are mixed, dried and ball-milled to obtain a mixture; S2. The mixture is placed in a pressure mold to be pressed into a green blank, and then the green blank is placed in a sintering furnace for sintering. After sintering, it is cooled to room temperature to obtain a high-temperature resistant cemented carbide.
[0007] Furthermore, in step S1, the drying temperature is 80-88℃ and the drying time is 10-15 min.
[0008] Furthermore, in step S1, the ball milling is carried out using a ball mill, the ball material is silicon carbide ceramic grinding balls with a diameter of 10 mm, the ball-to-material ratio in the ball mill is (5-10):1, the rotation speed is 1000-1200 r / min, and the ball milling time is 10-12 h.
[0009] Furthermore, in step S2, the pressing pressure is 250-300 MPa, and the pressing time is 2-3 min.
[0010] Furthermore, in step S2, the sintering temperature is 1580-1660℃, and the high-temperature sintering time is 3-4h.
[0011] Furthermore, the composite additive is prepared by the following steps: A1. Add tannic acid to ethanol and stir until completely dissolved. Add yttrium oxide and stir evenly. Add nano-zirconium carbide and continue stirring. After filtration, washing, and drying, core-shell particles are obtained. A2. Add the core-shell particles to ethanol and deionized water, stir until homogeneous, add aminosilane, stir to react, cool to room temperature, filter, wash, and dry to obtain modified core-shell particles. A3. Add sulfonated lignin to deionized water, stir evenly, add sodium hydroxide solution to adjust pH, add boric acid, stir and react, then add hydrochloric acid to adjust pH, add modified core-shell particles, continue stirring and reacting, filter, wash, and dry to obtain composite core-shell particles. A4. Mix carboxymethyl cellulose and deionized water, stir until completely dissolved, add carbon fiber, stir evenly, add composite core-shell particles, continue stirring, filter, wash, and dry to obtain composite additive.
[0012] In the A1 reaction process described above, tannic acid contains a large number of phenolic hydroxyl groups, which have good adhesion properties, allowing nano-zirconium carbide to adhere to the surface of yttrium oxide through tannic acid, thus obtaining core-shell particles.
[0013] During the A2 reaction described above, the silanol groups generated by the hydrolysis of aminosilane can chemically bond with the hydroxyl groups on the surface of the core-shell particles, thereby grafting aminosilane onto the surface of the core-shell particles and obtaining modified core-shell particles.
[0014] During the A3 reaction described above, the oxygen-containing functional groups of sulfonated lignin can react with the boron hydroxyl groups of boric acid, causing the lignin to form a cross-linked network structure. Furthermore, the amino groups on the surface of the modified core-shell particles can also bind with sulfonated lignin and boric acid through hydrogen bonds, resulting in the modified core-shell particles being uniformly dispersed in the lignin cross-linked network structure, thus obtaining composite core-shell particles.
[0015] During the A4 reaction process described above, carboxymethyl cellulose exhibits good adhesion, and its carboxyl groups can combine with oxygen-containing functional groups on the carbon fiber surface, allowing carboxymethyl cellulose to coat the carbon fiber surface and impart active functional groups to the carbon fiber. This enables the composite core-shell particles to be adsorbed onto the carbon fiber surface, serving as a composite additive.
[0016] Further, in step A1, the mass ratio of tannic acid, ethanol, yttrium oxide and nano-zirconium carbide is (0.4-1):(50-60):(2.5-3):(1.5-1.8).
[0017] Further, in step A2, the mass ratio of core-shell particles, ethanol, deionized water and aminosilane is (3-3.3):(80-90):(30-40):(1-1.2).
[0018] Further, in step A3, the mass ratio of sulfonated lignin, deionized water, boric acid and modified core-shell particles is (3.5-4):(90-100):(1.2-1.5):(2-2.5).
[0019] Further, in step A4, the mass ratio of carboxymethyl cellulose, deionized water, carbon fiber and composite core-shell particles is (1-1.4):(100-110):(4.5-4.8):(2-2.3).
[0020] The present invention has the following beneficial effects: (1) In the technical solution of the present invention, nano-zirconium carbide is adhered to the surface of yttrium oxide by tannic acid. On the one hand, during the sintering process of cemented carbide, yttrium oxide has excellent fluidity and can fill the pores of cemented carbide, improve the density, and thus improve the mechanical properties of cemented carbide. Moreover, as a carrier of nano-zirconium carbide, yttrium oxide can increase the surface roughness of yttrium oxide, increase the contact area with cemented carbide raw materials, and improve the density and mechanical properties of the alloy. On the other hand, during the sintering process of cemented carbide, nano-zirconium carbide combines with yttrium and oxygen elements in yttrium oxide to generate nano-sized Y2Zr2O7 phase, which is dispersed at the alloy interface, promotes the grain refinement of cemented carbide, and improves the mechanical properties and high temperature resistance of cemented carbide.
[0021] (2) In the technical solution of the present invention, aminosilane is grafted onto the surface of the core-shell particles, and active functional groups amino are introduced into the surface of the core-shell particles, which is beneficial for the core-shell particles to be embedded into the lignin-based cross-linked network structure, thereby improving the dispersibility of the core-shell particles in the cemented carbide and thus improving the mechanical properties and high temperature resistance of the cemented carbide. The modified core-shell particles react with sulfonated lignin and boric acid, resulting in uniform dispersion of the modified core-shell particles within the lignin cross-linked network structure. On one hand, during the sintering process of the cemented carbide, the cross-linked network structure formed by lignin and boric acid on the surface of the modified core-shell particles carbonizes, forming a cross-linked carbon network structure that disperses within the cemented carbide, improving its mechanical properties and high-temperature resistance. On the other hand, the nano-sized Y2Zr2O7 phase formed by the modified core-shell particles disperses within the cross-linked carbon network structure, exhibiting adsorption properties that ensure uniform dispersion of the nano-sized Y2Zr2O7 phase at the cemented carbide interface. This prevents the nano-sized Y2Zr2O7 phase from agglomerating within the cemented carbide, thus maintaining its structural uniformity and improving its mechanical properties and high-temperature resistance. Furthermore, the formed cross-linked carbon network structure can absorb and weaken the attractive forces generated by external forces, further enhancing the mechanical properties of the cemented carbide.
[0022] (3) In the technical solution of the present invention, carboxymethyl cellulose is coated on the surface of carbon fiber to give the carbon fiber active functional groups, thereby adsorbing the composite core-shell particles on the surface of carbon fiber. On the one hand, carbon fiber, as a carrier of composite core-shell particles, can carry more composite core-shell particles, which is conducive to the uniform dispersion of composite core-shell particles in the alloy raw materials, so that the prepared cemented carbide has high mechanical properties and high temperature resistance. On the other hand, carbon fiber is dispersed in the alloy matrix and can bear the load through the interfacial bonding force, prevent the movement of dislocations in the cemented carbide matrix, and significantly improve the mechanical properties of cemented carbide. In addition, carboxymethyl cellulose is carbonized during the sintering process, which can supplement carbon elements and increase the metal carbide phase in the alloy system. The metal carbide phase is dispersed in the alloy system, which improves the mechanical properties and high temperature resistance of the alloy. Detailed Implementation
[0023] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0024] The raw materials used in the embodiments of this invention are shown below, and all reagents used are analytical grade.
[0025] The tungsten carbide powder, with a Fisher particle size of 1.5µm, was purchased from Xiamen Jinlu Special Alloy Co., Ltd.
[0026] Cobalt powder: Fischer particle size 3.5µm, purchased from Bohuas Nanotechnology (Ningbo) Co., Ltd.
[0027] Nickel powder: 2.5µm Fisher particle size, purchased from Shanghai Shuitian Technology Co., Ltd.
[0028] Iron powder: average particle size 2.5µm, purchased from Ultramicro Nano Co., Ltd.
[0029] The niobium powder had an average particle size of 3.5µm and the tantalum powder had an average particle size of 4µm, and were purchased from Shanghai Maclean Biochemical Technology Co., Ltd.
[0030] Yttrium oxide with a particle size of 500 nm, product number JLY-P04, was purchased from Qinghe County Chaotai Metal Materials Co., Ltd.
[0031] The nano-zirconium carbide particles have a diameter of 50 nm and were purchased from Shanghai Yingfeng Ruihuang Metal Materials Co., Ltd.
[0032] The carbon fiber has a diameter of 1.5µm and a length of 10µm.
[0033] The aminosilane is (3-aminopropyl)triethoxysilane.
[0034] The sulfonated lignin, model MDH, was purchased from Hubei Maidehao Biotechnology Co., Ltd.
[0035] Example 1 A high-temperature resistant cemented carbide comprises the following raw materials in parts by weight: 80 parts tungsten carbide powder, 1.5 parts cobalt powder, 2 parts nickel powder, 1 part iron powder, 0.5 parts niobium powder, 0.5 parts tantalum powder, and 3 parts composite additives. A method for preparing a high-temperature resistant cemented carbide includes the following preparation steps: S1. Tungsten carbide powder, cobalt powder, nickel powder, iron powder, niobium powder, tantalum powder and composite additives are mixed, dried and ball-milled to obtain a mixture; wherein, the drying temperature is 80℃ and the drying time is 10min; ball milling is carried out using a ball mill, the ball material is silicon carbide ceramic grinding balls with a diameter of 10mm, the ball-to-material ratio in the ball mill is 5:1, the rotation speed is 1000r / min, and the ball milling time is 10h; S2. The mixture is placed in a pressure mold to be pressed into a green blank, and then the green blank is placed in a sintering furnace for sintering. After sintering, it is cooled to room temperature to obtain a high-temperature resistant cemented carbide. The pressing pressure is 250 MPa, the pressing time is 2 min, the sintering temperature is 1580℃, and the high-temperature sintering time is 3 h.
[0036] The composite additive is specifically prepared by the following steps: A1. Add tannic acid to ethanol and stir until completely dissolved. Add yttrium oxide and stir at 70°C for 40 min. Add nano-zirconium carbide and continue stirring for 40 min. After filtration, wash three times with deionized water and dry in an oven at 70°C for 10 min to obtain core-shell particles. The mass ratio of tannic acid, ethanol, yttrium oxide and nano-zirconium carbide is 0.4:50:2.5:1.5. A2. The core-shell particles were added to ethanol and deionized water and stirred until homogeneous. Then (3-aminopropyl)triethoxysilane was added and the mixture was stirred at 70°C for 1.5 h. After cooling to room temperature, the mixture was filtered, washed three times with ethanol and three times with deionized water, and dried in an oven at 70°C for 10 min to obtain modified core-shell particles. The mass ratio of core-shell particles, ethanol, deionized water and (3-aminopropyl)triethoxysilane was 3:80:30:1. A3. Sulfonated lignin was added to deionized water and stirred until homogeneous. The pH was adjusted to 11 with 0.1 mol / L sodium hydroxide solution, followed by the addition of boric acid. The mixture was stirred at 75°C for 1.5 h. Then, 0.1 mol / L hydrochloric acid was added to adjust the pH to 2.5. Modified core-shell particles were added, and the mixture was stirred for another 1.5 h. After filtration, the mixture was washed three times with deionized water and dried in an oven at 80°C for 10 min to obtain composite core-shell particles. The mass ratio of sulfonated lignin, deionized water, boric acid, and modified core-shell particles was 3.5:90:1.2:2. A4. Mix carboxymethyl cellulose and deionized water, stir until completely dissolved, add carbon fiber, stir at 60℃ for 30 min, add composite core-shell particles, continue stirring for 30 min, filter, wash 3 times with deionized water, and dry in an oven at 60℃ for 20 min to obtain composite additive; the mass ratio of carboxymethyl cellulose, deionized water, carbon fiber and composite core-shell particles is 1:100:4.5:2.
[0037] Example 2 A high-temperature resistant cemented carbide comprises the following raw materials in parts by weight: 85 parts tungsten carbide powder, 1.8 parts cobalt powder, 2.5 parts nickel powder, 1.5 parts iron powder, 0.8 parts niobium powder, 0.8 parts tantalum powder, and 4 parts composite additives; A method for preparing a high-temperature resistant cemented carbide includes the following preparation steps: S1. Tungsten carbide powder, cobalt powder, nickel powder, iron powder, niobium powder, tantalum powder and composite additives are mixed, dried and ball-milled to obtain a mixture; wherein, the drying temperature is 85℃ and the drying time is 13min; ball milling is carried out using a ball mill, the ball material is silicon carbide ceramic grinding balls with a diameter of 10mm, the ball-to-material ratio in the ball mill is 8:1, the rotation speed is 1100r / min, and the ball milling time is 11h; S2. The mixture is placed in a pressure mold to be pressed into a green blank, and then the green blank is placed in a sintering furnace for sintering. After sintering, it is cooled to room temperature to obtain a high-temperature resistant cemented carbide. The pressing pressure is 280 MPa, the pressing time is 2.5 min, the sintering temperature is 1620℃, and the high-temperature sintering time is 3.5 h.
[0038] The composite additive is specifically prepared by the following steps: A1. Add tannic acid to ethanol and stir until completely dissolved. Add yttrium oxide and stir at 70°C for 40 min. Add nano-zirconium carbide and continue stirring for 40 min. After filtration, wash three times with deionized water and dry in an oven at 70°C for 10 min to obtain core-shell particles. The mass ratio of tannic acid, ethanol, yttrium oxide and nano-zirconium carbide is 0.7:55:2.8:1.6. A2. The core-shell particles were added to ethanol and deionized water and stirred until homogeneous. Then (3-aminopropyl)triethoxysilane was added and the mixture was stirred at 70°C for 1.5 h. After cooling to room temperature, the mixture was filtered, washed three times with ethanol and three times with deionized water, and dried in an oven at 70°C for 10 min to obtain modified core-shell particles. The mass ratio of core-shell particles, ethanol, deionized water and (3-aminopropyl)triethoxysilane was 3.2:85:35:1.1. A3. Sulfonated lignin was added to deionized water and stirred until homogeneous. The pH was adjusted to 11 with 0.1 mol / L sodium hydroxide solution, followed by the addition of boric acid. The mixture was stirred at 75°C for 1.5 h. Then, 0.1 mol / L hydrochloric acid was added to adjust the pH to 2.5. Modified core-shell particles were added, and the mixture was stirred for another 1.5 h. After filtration, the mixture was washed three times with deionized water and dried in an oven at 80°C for 10 min to obtain composite core-shell particles. The mass ratio of sulfonated lignin, deionized water, boric acid, and modified core-shell particles was 3.8:95:1.3:2.4. A4. Mix carboxymethyl cellulose and deionized water, stir until completely dissolved, add carbon fiber, stir at 60℃ for 30 min, add composite core-shell particles, continue stirring for 30 min, filter, wash three times with deionized water, and dry in a 60℃ oven for 20 min to obtain composite additive; the mass ratio of carboxymethyl cellulose, deionized water, carbon fiber and composite core-shell particles is 1.2:105:4.7:2.2.
[0039] Example 3 A high-temperature resistant cemented carbide comprises the following raw materials in parts by weight: 90 parts tungsten carbide powder, 2 parts cobalt powder, 3 parts nickel powder, 2 parts iron powder, 1 part niobium powder, 1 part tantalum powder, and 5 parts composite additives. A method for preparing a high-temperature resistant cemented carbide includes the following preparation steps: S1. Tungsten carbide powder, cobalt powder, nickel powder, iron powder, niobium powder, tantalum powder and composite additives are mixed, dried and ball-milled to obtain a mixture; wherein, the drying temperature is 88℃ and the drying time is 15min; ball milling is carried out using a ball mill, the ball material is silicon carbide ceramic grinding balls with a diameter of 10mm, the ball-to-material ratio in the ball mill is 10:1, the rotation speed is 1200r / min, and the ball milling time is 12h; S2. The mixture is placed in a pressure mold to be pressed into a green blank, and then the green blank is placed in a sintering furnace for sintering. After sintering, it is cooled to room temperature to obtain a high-temperature resistant cemented carbide. The pressing pressure is 300 MPa, the pressing time is 3 min, the sintering temperature is 1660℃, and the high-temperature sintering time is 4 h.
[0040] The composite additive is specifically prepared by the following steps: A1. Add tannic acid to ethanol and stir until completely dissolved. Add yttrium oxide and stir at 70°C for 40 min. Add nano-zirconium carbide and continue stirring for 40 min. After filtration, wash three times with deionized water and dry in an oven at 70°C for 10 min to obtain core-shell particles. The mass ratio of tannic acid, ethanol, yttrium oxide and nano-zirconium carbide is 1:60:3:1.8. A2. The core-shell particles were added to ethanol and deionized water and stirred until homogeneous. Then (3-aminopropyl)triethoxysilane was added, and the mixture was stirred at 70°C for 1.5 h. After cooling to room temperature, the mixture was filtered, washed three times with ethanol, and three times with deionized water. The mixture was then dried in an oven at 70°C for 10 min to obtain the modified core-shell particles. The mass ratio of core-shell particles, ethanol, deionized water, and (3-aminopropyl)triethoxysilane was 3.3:90:40:1.2. A3. Sulfonated lignin was added to deionized water and stirred until homogeneous. The pH was adjusted to 11 with 0.1 mol / L sodium hydroxide solution, followed by the addition of boric acid. The mixture was stirred at 75°C for 1.5 h. Then, 0.1 mol / L hydrochloric acid was added to adjust the pH to 2.5. Modified core-shell particles were added, and the mixture was stirred for another 1.5 h. After filtration, the mixture was washed three times with deionized water and dried in an oven at 80°C for 10 min to obtain composite core-shell particles. The mass ratio of sulfonated lignin, deionized water, boric acid, and modified core-shell particles was 4:100:1.5:2.5. A4. Mix carboxymethyl cellulose and deionized water, stir until completely dissolved, add carbon fiber, stir at 60℃ for 30 min, add composite core-shell particles, continue stirring for 30 min, filter, wash three times with deionized water, and dry in a 60℃ oven for 20 min to obtain composite additive; the mass ratio of carboxymethyl cellulose, deionized water, carbon fiber and composite core-shell particles is 1.4:110:4.8:2.3.
[0041] Comparative Example 1 A high-temperature resistant cemented carbide comprises the following raw materials in parts by weight: 90 parts tungsten carbide powder, 2 parts cobalt powder, 3 parts nickel powder, 2 parts iron powder, 1 part niobium powder, 1 part tantalum powder, and 5 parts composite additives. A method for preparing a high-temperature resistant cemented carbide includes the following preparation steps: S1. Tungsten carbide powder, cobalt powder, nickel powder, iron powder, niobium powder, tantalum powder and composite additives are mixed, dried and ball-milled to obtain a mixture; wherein, the drying temperature is 88℃ and the drying time is 15min; ball milling is carried out using a ball mill, the ball material is silicon carbide ceramic grinding balls with a diameter of 10mm, the ball-to-material ratio in the ball mill is 10:1, the rotation speed is 1200r / min, and the ball milling time is 12h; S2. The mixture is placed in a pressure mold to be pressed into a green blank, and then the green blank is placed in a sintering furnace for sintering. After sintering, it is cooled to room temperature to obtain a high-temperature resistant cemented carbide. The pressing pressure is 300 MPa, the pressing time is 3 min, the sintering temperature is 1660℃, and the high-temperature sintering time is 4 h.
[0042] The composite additive is specifically prepared by the following steps: A1. Ethanol and yttrium oxide were stirred at 70°C for 40 min, nano-zirconium carbide was added, and stirring was continued for another 40 min. After filtration, the mixture was washed three times with deionized water and dried in an oven at 70°C for 10 min to obtain a mixture. The mass ratio of ethanol, yttrium oxide and nano-zirconium carbide was 60:3:2.8. A2. Add the mixture to ethanol and deionized water, stir until homogeneous, add (3-aminopropyl)triethoxysilane, stir and react at 70℃ for 1.5h, cool to room temperature, filter, wash 3 times with ethanol and 3 times with deionized water, and dry in an oven at 70℃ for 10min to obtain the modified mixture; the mass ratio of the mixture, ethanol, deionized water and (3-aminopropyl)triethoxysilane is 3.3:90:40:1.2; A3. Sulfonated lignin was added to deionized water and stirred until homogeneous. The pH was adjusted to 11 with 0.1 mol / L sodium hydroxide solution, followed by the addition of boric acid. The mixture was stirred at 75°C for 1.5 h. Then, 0.1 mol / L hydrochloric acid was added to adjust the pH to 2.5. The modified mixture was added, and stirring continued for 1.5 h. After filtration, the mixture was washed three times with deionized water and dried in an oven at 80°C for 10 min to obtain the composite. The mass ratio of sulfonated lignin, deionized water, boric acid, and the modified mixture was 4:100:1.5:2.5. A4. Mix carboxymethyl cellulose and deionized water, stir until completely dissolved, add carbon fiber, stir at 60℃ for 30 min, add the composite, continue stirring for 30 min, filter, wash three times with deionized water, and dry in an oven at 60℃ for 20 min to obtain the composite additive; the mass ratio of carboxymethyl cellulose, deionized water, carbon fiber and composite is 1.4:110:4.8:2.3.
[0043] Comparative Example 2 A high-temperature resistant cemented carbide comprises the following raw materials in parts by weight: 90 parts tungsten carbide powder, 2 parts cobalt powder, 3 parts nickel powder, 2 parts iron powder, 1 part niobium powder, 1 part tantalum powder, and 5 parts composite additives. A method for preparing a high-temperature resistant cemented carbide includes the following preparation steps: S1. Tungsten carbide powder, cobalt powder, nickel powder, iron powder, niobium powder, tantalum powder and composite additives are mixed, dried and ball-milled to obtain a mixture; wherein, the drying temperature is 88℃ and the drying time is 15min; ball milling is carried out using a ball mill, the ball material is silicon carbide ceramic grinding balls with a diameter of 10mm, the ball-to-material ratio in the ball mill is 10:1, the rotation speed is 1200r / min, and the ball milling time is 12h; S2. The mixture is placed in a pressure mold to be pressed into a green blank, and then the green blank is placed in a sintering furnace for sintering. After sintering, it is cooled to room temperature to obtain a high-temperature resistant cemented carbide. The pressing pressure is 300 MPa, the pressing time is 3 min, the sintering temperature is 1660℃, and the high-temperature sintering time is 4 h.
[0044] The composite additive is specifically prepared by the following steps: A1. Add tannic acid to ethanol and stir until completely dissolved. Add yttrium oxide and stir at 70°C for 40 min. Add nano-zirconium carbide and continue stirring for 40 min. After filtration, wash three times with deionized water and dry in an oven at 70°C for 10 min to obtain core-shell particles. The mass ratio of tannic acid, ethanol, yttrium oxide and nano-zirconium carbide is 1:60:3:1.8. A2. Sulfonated lignin was added to deionized water and stirred until homogeneous. The pH was adjusted to 11 with 0.1 mol / L sodium hydroxide solution, followed by the addition of boric acid. The mixture was stirred at 75°C for 1.5 h. Then, 0.1 mol / L hydrochloric acid was added to adjust the pH to 2.5. Core-shell particles were added, and the mixture was stirred for another 1.5 h. After filtration, the mixture was washed three times with deionized water and dried in an oven at 80°C for 10 min to obtain composite core-shell particles. The mass ratio of sulfonated lignin, deionized water, boric acid, and core-shell particles was 4:100:1.5:2.5. A3. Mix carboxymethyl cellulose and deionized water, stir until completely dissolved, add carbon fiber, stir at 60℃ for 30 min, add composite core-shell particles, continue stirring for 30 min, filter, wash three times with deionized water, and dry in a 60℃ oven for 20 min to obtain composite additive; the mass ratio of carboxymethyl cellulose, deionized water, carbon fiber and composite core-shell particles is 1.4:110:4.8:2.3.
[0045] Comparative Example 3 A high-temperature resistant cemented carbide comprises the following raw materials in parts by weight: 90 parts tungsten carbide powder, 2 parts cobalt powder, 3 parts nickel powder, 2 parts iron powder, 1 part niobium powder, 1 part tantalum powder, and 5 parts composite additives. A method for preparing a high-temperature resistant cemented carbide includes the following preparation steps: S1. Tungsten carbide powder, cobalt powder, nickel powder, iron powder, niobium powder, tantalum powder and composite additives are mixed, dried and ball-milled to obtain a mixture; wherein, the drying temperature is 88℃ and the drying time is 15min; ball milling is carried out using a ball mill, the ball material is silicon carbide ceramic grinding balls with a diameter of 10mm, the ball-to-material ratio in the ball mill is 10:1, the rotation speed is 1200r / min, and the ball milling time is 12h; S2. The mixture is placed in a pressure mold to be pressed into a green blank, and then the green blank is placed in a sintering furnace for sintering. After sintering, it is cooled to room temperature to obtain a high-temperature resistant cemented carbide. The pressing pressure is 300 MPa, the pressing time is 3 min, the sintering temperature is 1660℃, and the high-temperature sintering time is 4 h.
[0046] The composite additive is specifically prepared by the following steps: A1. Add tannic acid to ethanol and stir until completely dissolved. Add yttrium oxide and stir at 70°C for 40 min. Add nano-zirconium carbide and continue stirring for 40 min. After filtration, wash three times with deionized water and dry in an oven at 70°C for 10 min to obtain core-shell particles. The mass ratio of tannic acid, ethanol, yttrium oxide and nano-zirconium carbide is 1:60:3:1.8. A2. The core-shell particles were added to ethanol and deionized water and stirred until homogeneous. Then (3-aminopropyl)triethoxysilane was added, and the mixture was stirred at 70°C for 1.5 h. After cooling to room temperature, the mixture was filtered, washed three times with ethanol, and three times with deionized water. The mixture was then dried in an oven at 70°C for 10 min to obtain the modified core-shell particles. The mass ratio of core-shell particles, ethanol, deionized water, and (3-aminopropyl)triethoxysilane was 3.3:90:40:1.2. A3. Mix deionized water and boric acid, stir at 75℃ for 1.5h, add 0.1mol / L hydrochloric acid to adjust the pH to 2.5, add modified core-shell particles, continue stirring for 1.5h, filter, wash three times with deionized water, and dry in an oven at 80℃ for 10min to obtain composite core-shell particles; the mass ratio of deionized water, boric acid and modified core-shell particles is 100:5.5:2.5; A4. Mix carboxymethyl cellulose and deionized water, stir until completely dissolved, add carbon fiber, stir at 60℃ for 30 min, add composite core-shell particles, continue stirring for 30 min, filter, wash three times with deionized water, and dry in a 60℃ oven for 20 min to obtain composite additive; the mass ratio of carboxymethyl cellulose, deionized water, carbon fiber and composite core-shell particles is 1.4:110:4.8:2.3.
[0047] Comparative Example 4 A high-temperature resistant cemented carbide comprises the following raw materials in parts by weight: 90 parts tungsten carbide powder, 2 parts cobalt powder, 3 parts nickel powder, 2 parts iron powder, 1 part niobium powder, 1 part tantalum powder, and 5 parts composite additives. A method for preparing a high-temperature resistant cemented carbide includes the following preparation steps: S1. Tungsten carbide powder, cobalt powder, nickel powder, iron powder, niobium powder, tantalum powder and composite additives are mixed, dried and ball-milled to obtain a mixture; wherein, the drying temperature is 88℃ and the drying time is 15min; ball milling is carried out using a ball mill, the ball material is silicon carbide ceramic grinding balls with a diameter of 10mm, the ball-to-material ratio in the ball mill is 10:1, the rotation speed is 1200r / min, and the ball milling time is 12h; S2. The mixture is placed in a pressure mold to be pressed into a green blank, and then the green blank is placed in a sintering furnace for sintering. After sintering, it is cooled to room temperature to obtain a high-temperature resistant cemented carbide. The pressing pressure is 300 MPa, the pressing time is 3 min, the sintering temperature is 1660℃, and the high-temperature sintering time is 4 h.
[0048] The composite additive is specifically prepared by the following steps: A1. Add tannic acid to ethanol and stir until completely dissolved. Add yttrium oxide and stir at 70°C for 40 min. Add nano-zirconium carbide and continue stirring for 40 min. After filtration, wash three times with deionized water and dry in an oven at 70°C for 10 min to obtain core-shell particles. The mass ratio of tannic acid, ethanol, yttrium oxide and nano-zirconium carbide is 1:60:3:1.8. A2. The core-shell particles were added to ethanol and deionized water and stirred until homogeneous. Then (3-aminopropyl)triethoxysilane was added, and the mixture was stirred at 70°C for 1.5 h. After cooling to room temperature, the mixture was filtered, washed three times with ethanol, and three times with deionized water. The mixture was then dried in an oven at 70°C for 10 min to obtain the modified core-shell particles. The mass ratio of core-shell particles, ethanol, deionized water, and (3-aminopropyl)triethoxysilane was 3.3:90:40:1.2. A3. Sulfonated lignin was added to deionized water and stirred until homogeneous. The pH was adjusted to 11 with 0.1 mol / L sodium hydroxide solution, followed by the addition of boric acid. The mixture was stirred at 75°C for 1.5 h. Then, 0.1 mol / L hydrochloric acid was added to adjust the pH to 2.5. Modified core-shell particles were added, and the mixture was stirred for another 1.5 h. After filtration, the mixture was washed three times with deionized water and dried in an oven at 80°C for 10 min to obtain composite core-shell particles. The mass ratio of sulfonated lignin, deionized water, boric acid, and modified core-shell particles was 4:100:1.5:2.5. A4. Mix deionized water and carbon fiber, stir at 60℃ for 30 min, add composite core-shell particles, continue stirring for 30 min, filter, wash 3 times with deionized water, and dry in an oven at 60℃ for 20 min to obtain composite additive; the mass ratio of deionized water, carbon fiber and composite core-shell particles is 110:6.2:2.3.
[0049] Comparative Example 5 A high-temperature resistant cemented carbide comprises the following raw materials in parts by weight: 90 parts tungsten carbide powder, 2 parts cobalt powder, 3 parts nickel powder, 2 parts iron powder, 1 part niobium powder, 1 part tantalum powder, and 5 parts composite additives. A method for preparing a high-temperature resistant cemented carbide includes the following preparation steps: S1. Tungsten carbide powder, cobalt powder, nickel powder, iron powder, niobium powder, tantalum powder and composite additives are mixed, dried and ball-milled to obtain a mixture; wherein, the drying temperature is 88℃ and the drying time is 15min; ball milling is carried out using a ball mill, the ball material is silicon carbide ceramic grinding balls with a diameter of 10mm, the ball-to-material ratio in the ball mill is 10:1, the rotation speed is 1200r / min, and the ball milling time is 12h; S2. The mixture is placed in a pressure mold to be pressed into a green blank, and then the green blank is placed in a sintering furnace for sintering. After sintering, it is cooled to room temperature to obtain a high-temperature resistant cemented carbide. The pressing pressure is 300 MPa, the pressing time is 3 min, the sintering temperature is 1660℃, and the high-temperature sintering time is 4 h.
[0050] The composite additive is specifically prepared by the following steps: A1. Add tannic acid to ethanol and stir until completely dissolved. Add yttrium oxide and stir at 70°C for 40 min. Add nano-zirconium carbide and continue stirring for 40 min. After filtration, wash three times with deionized water and dry in an oven at 70°C for 10 min to obtain core-shell particles. The mass ratio of tannic acid, ethanol, yttrium oxide and nano-zirconium carbide is 1:60:3:1.8. A2. The core-shell particles were added to ethanol and deionized water and stirred until homogeneous. Then (3-aminopropyl)triethoxysilane was added, and the mixture was stirred at 70°C for 1.5 h. After cooling to room temperature, the mixture was filtered, washed three times with ethanol, and three times with deionized water. The mixture was then dried in an oven at 70°C for 10 min to obtain the modified core-shell particles. The mass ratio of core-shell particles, ethanol, deionized water, and (3-aminopropyl)triethoxysilane was 3.3:90:40:1.2. A3. Sulfonated lignin was added to deionized water and stirred until homogeneous. The pH was adjusted to 11 with 0.1 mol / L sodium hydroxide solution, followed by the addition of boric acid. The mixture was stirred at 75°C for 1.5 h. Then, 0.1 mol / L hydrochloric acid was added to adjust the pH to 2.5. Modified core-shell particles were added, and the mixture was stirred for another 1.5 h. After filtration, the mixture was washed three times with deionized water and dried in an oven at 80°C for 10 min to obtain composite core-shell particles. The mass ratio of sulfonated lignin, deionized water, boric acid, and modified core-shell particles was 4:100:1.5:2.5. A4. Mix carboxymethyl cellulose and deionized water, stir until completely dissolved, add composite core-shell particles, continue stirring for 30 min, filter, wash 3 times with deionized water, and dry in an oven at 60℃ for 20 min to obtain composite additive; the mass ratio of carboxymethyl cellulose, deionized water and composite core-shell particles is 1.4:110:7.1.
[0051] The performance of the high-temperature resistant cemented carbides prepared in Examples 1-3 and Comparative Examples 1-5 was then tested.
[0052] Mechanical performance testing: The yield strength and tensile strength of the cemented carbide bearings prepared above were determined in accordance with GB / T228-2010 (Metallic materials, tensile test at room temperature).
[0053] Hardness (HRA) test: The hardness value of the high temperature resistant cemented carbide prepared above was tested according to the standard GB / T3849.1-2015; the cemented carbide bearing prepared above was placed at 1000℃ and the hardness value of the cemented carbide bearing at high temperature was tested.
[0054] The test results are shown in Table 1.
[0055] Table 1. Performance testing of high-temperature resistant cemented carbides prepared in Examples 1-3 and Comparative Examples 1-5
[0056] As can be seen from the data in Table 1, the high-temperature resistant cemented carbides prepared in Examples 1-3 have high mechanical strength and good high-temperature resistance.
[0057] Comparative Example 1 showed that when tannic acid was replaced by a composite additive made of nano-zirconium carbide, its mechanical properties and high-temperature resistance decreased. This demonstrates that nano-zirconium carbide can adhere to the surface of yttrium oxide through tannic acid to form core-shell particles, which can increase the surface roughness of yttrium oxide, increase the contact area with the cemented carbide raw material, and improve the density and mechanical properties of the alloy. Furthermore, nano-zirconium carbide combines with yttrium and oxygen elements in yttrium oxide to form a nano-sized Y2Zr2O7 phase, which is dispersed at the alloy interface, promoting the grain refinement of the cemented carbide and thus improving its mechanical properties and high-temperature resistance.
[0058] Comparative Example 2 showed that when the modified core-shell particles were replaced with a composite additive prepared from core-shell particles and added to a high-temperature resistant cemented carbide, its mechanical properties and high-temperature resistance decreased. This demonstrates that the grafting of aminosilane onto the surface of the core-shell particles introduces active functional groups of amino groups, which is beneficial for the core-shell particles to be embedded in the lignin-based cross-linked network structure, thereby improving the dispersibility of the core-shell particles in the cemented carbide and thus improving the mechanical properties and high-temperature resistance of the cemented carbide.
[0059] Comparative Example 3 showed that when a composite additive prepared by replacing sulfonated lignin with boric acid was added to a high-temperature resistant cemented carbide, its mechanical properties and high-temperature resistance decreased. This demonstrates that the reaction between sulfonated lignin and boric acid forms a cross-linked network structure, which allows the modified core-shell particles to be uniformly dispersed in the lignin cross-linked network structure, improving the dispersibility of the core-shell particles in the cemented carbide. Furthermore, during the sintering process of the cemented carbide, the formed cross-linked network structure carbonizes, forming a cross-linked carbon network structure dispersed in the cemented carbide, thus improving the mechanical properties and high-temperature resistance of the cemented carbide. In addition, the nano-sized Y2Zr2O7 phase formed by the modified core-shell particles is dispersed in the cross-linked carbon network structure, which has an adsorption effect on the nano-sized Y2Zr2O7 phase, making the nano-sized Y2Zr2O7 phase uniformly dispersed at the cemented carbide interface, thus improving the mechanical properties and high-temperature resistance of the cemented carbide.
[0060] Comparative Example 4 showed that when carboxymethyl cellulose was replaced by carbon fiber as a composite additive in a high-temperature resistant cemented carbide, its mechanical properties and high-temperature resistance decreased. This demonstrates that carboxymethyl cellulose coating the carbon fiber surface imparts active functional groups to the carbon fiber, thereby adsorbing the composite core-shell particles onto the carbon fiber surface. This facilitates the uniform dispersion of the composite core-shell particles in the alloy raw materials, resulting in a cemented carbide with higher mechanical properties and high-temperature resistance. Furthermore, the carbonization of carboxymethyl cellulose during sintering replenishes carbon elements, increasing the presence of metal carbide phases in the alloy system. The dispersion of these metal carbide phases in the alloy system further enhances the mechanical properties and high-temperature resistance of the alloy.
[0061] Comparative Example 5 showed that when carbon fiber was replaced by a composite additive made of composite core-shell particles, the mechanical properties and high-temperature resistance of the cemented carbide decreased. This demonstrates that carbon fiber, as a carrier of composite core-shell particles, can support a large number of composite core-shell particles, which is beneficial for the uniform dispersion of composite core-shell particles in the alloy raw materials. Furthermore, the carbon fiber, dispersed in the alloy matrix, can bear the load through interfacial bonding forces, prevent dislocation movement in the cemented carbide matrix, and significantly improve the mechanical properties of the cemented carbide.
[0062] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0063] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.
Claims
1. A high-temperature resistant cemented carbide, characterized in that, The raw materials include the following parts by weight: 80-90 parts tungsten carbide powder, 1.5-2 parts cobalt powder, 2-3 parts nickel powder, 1-2 parts iron powder, 0.5-1 part niobium powder, 0.5-1 part tantalum powder, and 3-5 parts composite additives; The composite additive is obtained by modifying carbon fibers on the surface of carboxymethyl cellulose and then mixing them with composite core-shell particles; The composite core-shell particles are formed by adhering nano-zirconium carbide to the surface of yttrium oxide with tannic acid. The core-shell particles are then modified with aminosilane and reacted with sulfonated lignin and boric acid.
2. The high-temperature resistant cemented carbide according to claim 1, characterized in that, The composite additive is prepared by the following steps: A1. Add tannic acid to ethanol and stir until completely dissolved. Add yttrium oxide and stir evenly. Add nano-zirconium carbide and continue stirring. After filtration, washing, and drying, core-shell particles are obtained. A2. Add the core-shell particles to ethanol and deionized water, stir until homogeneous, add aminosilane, stir to react, cool to room temperature, filter, wash, and dry to obtain modified core-shell particles. A3. Add sulfonated lignin to deionized water, stir evenly, add sodium hydroxide solution to adjust pH, add boric acid, stir and react, then add hydrochloric acid to adjust pH, add modified core-shell particles, continue stirring and reacting, filter, wash, and dry to obtain composite core-shell particles. A4. Mix carboxymethyl cellulose and deionized water, stir until completely dissolved, add carbon fiber, stir evenly, add composite core-shell particles, continue stirring, filter, wash, and dry to obtain composite additive.
3. The high-temperature resistant cemented carbide according to claim 2, characterized in that, In step A1, the mass ratio of tannic acid, ethanol, yttrium oxide and nano-zirconium carbide is (0.4-1):(50-60):(2.5-3):(1.5-1.8).
4. The high-temperature resistant cemented carbide according to claim 2, characterized in that, In step A2, the mass ratio of the core-shell particles, ethanol, deionized water and aminosilane is (3-3.3):(80-90):(30-40):(1-1.2).
5. The high-temperature resistant cemented carbide according to claim 2, characterized in that, In step A3, the mass ratio of sulfonated lignin, deionized water, boric acid and modified core-shell particles is (3.5-4):(90-100):(1.2-1.5):(2-2.5).
6. The high-temperature resistant cemented carbide according to claim 2, characterized in that, In step A4, the mass ratio of carboxymethyl cellulose, deionized water, carbon fiber and composite core-shell particles is (1-1.4):(100-110):(4.5-4.8):(2-2.3).
7. A method for preparing a high-temperature resistant cemented carbide as described in any one of claims 1-6, characterized in that, The preparation steps include the following: S1. Tungsten carbide powder, cobalt powder, nickel powder, iron powder, niobium powder, tantalum powder and composite additives are mixed, dried and ball-milled to obtain a mixture; S2. The mixture is placed in a pressure mold to be pressed into a green blank, and then the green blank is placed in a sintering furnace for sintering. After sintering, it is cooled to room temperature to obtain a high-temperature resistant cemented carbide.
8. The method for preparing a high-temperature resistant cemented carbide according to claim 7, characterized in that, In step S1, the drying temperature is 80-88℃ and the drying time is 10-15 min.
9. The method for preparing a high-temperature resistant cemented carbide according to claim 7, characterized in that, In step S2, the pressing pressure is 250-300 MPa, and the pressing time is 2-3 min; The sintering temperature is 1580-1660℃, and the sintering time is 3-4h.