High-wear-resistance zirconium oxide coating silicon carbide material and preparation method thereof

Abstract

The invention relates to a high-wear-resistance zirconium oxide coating silicon carbide material and a preparation method thereof.The high-wear-resistance zirconium oxide coating silicon carbide material comprises a core layer and a coating, the core layer is prepared from, by weight, 45-85 parts of silicon carbide, 1-5 parts of aluminum oxide, 1-5 parts of magnesium oxide, 1-5 parts of zirconium oxide, 1-5 parts of silicon dioxide and 1-3 parts of additives, and the silicon carbide comprises large silicon carbide and small silicon carbide according to the mass ratio of (2-2.3): 1; the particle size of the large silicon carbide is 0.1 mm-2mm, and the particle size of the small silicon carbide is 0.01 mm-0. 08mm; the coating takes zirconium oxide as a matrix raw material. The zirconium oxide coating silicon carbide material is not prone to being damaged by thermal oxidation, has high abrasion resistance for a long time and is suitable for being used for chemical fluid pipelines.

Description

Technical Field

[0001] This application relates to the field of special wear-resistant ceramic materials, and more specifically, it relates to a high-wear-resistant zirconia-coated silicon carbide material and a preparation method thereof. Background Art

[0002] Silicon carbide ceramics have characteristics such as high hardness, high strength, high wear resistance, and good chemical stability, so they have been widely used in the fields of mechanical seals and wear-resistant components. For example, silicon carbide ceramic seals, silicon carbide ceramic bearings, silicon carbide ceramic wear-resistant plates, etc., can also be used in the chemical and environmental protection fields, such as silicon carbide ceramic pipes, silicon carbide ceramic filters, silicon carbide ceramic reactors, etc. These components can withstand various harsh environments such as strong acids, strong alkalis, and organic solvents, ensuring the continuity and stability of chemical production, and being beneficial to environmental protection and energy conservation and emission reduction. However, silicon carbide ceramics have poor oxidation resistance in high-temperature and low-oxygen environments. When used in scenarios such as chemical high-temperature fluid pipes, volute casings, and nozzles, slagging and cracking occur due to oxidation, and they quickly become damaged after being scoured and worn by particulate matter in the fluid. Therefore, how to provide a silicon carbide material for high-temperature and low-oxygen environments to maintain high wear resistance for a long time has high economic value. Summary of the Invention

[0003] In order to solve the problem of improving the wear resistance of silicon carbide ceramics in high-temperature and low-oxygen environments, this application provides a high-wear-resistant zirconia-coated silicon carbide material and a preparation method thereof.

[0004] In a first aspect, this application provides a high-wear-resistant zirconia-coated silicon carbide material, including a core layer and a coating. The core layer is made of the following raw materials in parts by weight: 45 - 85 parts of silicon carbide, 1 - 5 parts of alumina, 1 - 5 parts of magnesia, 1 - 5 parts of zirconia, 1 - 5 parts of silica, and 1 - 3 parts of an additive. The silicon carbide includes large silicon carbide and small silicon carbide with a mass ratio of (2 - 2.3):1. The large silicon carbide has a particle size of 0.1 mm - 2 mm, and the small silicon carbide has a particle size of 0.01 - 0.08 mm; the coating uses zirconia as the matrix raw material.

[0005] By adopting the above technical solution, silicon carbide with large particle size and silicon carbide with small particle size are used together. The small particle size silicon carbide achieves better filling inside the matrix, the core layer is more dense, and oxygen is not easily invaded. After being mixed evenly, there are certain protrusions on the surface of the large particle size silicon carbide, which increases the adhesion strength of the coating, enabling the zirconia coating to better protect the core layer. By adding a certain mass of alumina, magnesia, zirconia, and silica and using them together, the properties of the prepared core layer are more balanced, and it has good wear resistance after being stressed. By adding a certain mass of additives, especially tricresyl phosphate as an additive, the core layer material has good ductility and flexibility after being mixed, and the particles are more closely formed during the subsequent preparation and pressing process, further improving the density of the material, and heat and oxygen are not easily invaded. By limiting the particle size and mass ratio of large and small silicon carbides, too large a particle size will cause the core layer material to stack unevenly, and too small a particle size will cause insufficient surface roughness. Through repeated experiments, the applicant found a particle size combination with better performance under this formula.

[0006] Preferably, the silicon carbide includes large silicon carbide and small silicon carbide with a mass ratio of (2.1-2.2):1. The particle size of the large silicon carbide is 0.2 mm - 1 mm, and the particle size of the small silicon carbide is 0.01 - 0.05 mm.

[0007] In a specific feasible embodiment, the coating includes a first coating close to the core layer and a second coating far from the core layer. The first coating includes the following raw materials in parts by mass: 20 - 40 parts of zirconia, 15 - 20 parts of small silicon carbide, and 5 - 12 parts of flaky graphene. The second coating includes the following raw materials in parts by mass: 40 - 50 parts of zirconia, 25 - 35 parts of polytetrafluoroethylene, and 5 - 12 parts of flaky graphene.

[0008] By adopting the above technical solution, the first coating close to the core layer contains a certain mass of silicon carbide, which can achieve better connection with the core layer. A certain mass of flaky graphene is added to both the first coating and the second coating. The multi-layer stacking and shielding of the flaky graphene extend the path of heat and oxygen intrusion, further protecting the core layer and extending the service life of the prepared material. At the same time, it is possible that the mechanical interpenetration is realized by the flaky graphene between layers, and the short-term wear resistance of the prepared silicon carbide material also has better performance. By adding a certain mass of polytetrafluoroethylene to the second coating, the adhesion and retention of the fluid are reduced, further reducing the damage to the prepared material.

[0009] In a second aspect, the present application provides a preparation method of a high wear-resistant zirconia-coated silicon carbide material, including the following steps: mixing the core layer raw materials evenly, drying, pressing into shape, and sintering at high temperature to obtain the core layer, mixing the first coating and second coating raw materials evenly respectively, and sequentially melting them onto the surface of the core layer at high temperature to obtain the zirconia-coated silicon carbide material.

[0010] By adopting the above technical solutions, the preparation method is simple. At the same time, since there is also a small amount of zirconia as a raw material in the core layer, when the first coating is melted and sprayed onto the core layer at high temperature, it can melt a layer of zirconia on the surface of the core layer, realizing a better connection between the coating and the core layer. Since the core layer contains silicon carbide with different particle sizes and has a certain surface roughness, the coating raw materials are also more likely to be stably connected after being melted and sprayed onto the surface of the core layer. Through the setting of zirconia and silicon carbide with different particle sizes in the core layer, it is suitable for the preparation method of high-temperature melting and spraying, and the connection strength between the obtained coating and the core layer is high.

[0011] In a specific feasible embodiment, the thickness of the first coating is 0.1 - 10 mm, and the thickness of the second coating is 0.1 - 3 mm.

[0012] In a specific feasible embodiment, the flaky graphene in the first coating is flaky graphene modified by dodecyl silane coupling agent, and the flaky graphene in the second coating is flaky graphene modified by octadecyl silane coupling agent.

[0013] By adopting the above technical solutions, the modified flaky graphene achieves better dispersion and orientation. At the same time, it may be due to the different masses of the modified flaky graphene that different accelerations are obtained during the high-temperature melting and spraying process. After high-temperature melting and spraying, the flaky graphene modified by octadecyl silane coupling agent and the flaky graphene modified by dodecyl silane coupling agent are more densely distributed at the interface where the first coating and the second coating are connected. As a result, the silicon carbide raw materials in the first coating are more densely distributed on the side close to the surface of the core layer, and similar materials achieve a closer connection. The modified flaky graphene forms better interpenetration at the interface where the first coating and the second coating are connected. Through the interpenetration of modified graphene and the melting of silicon carbide between layers, the obtained zirconia coating silicon carbide material has a dense structure, is not easily invaded by heat and oxygen, and has good long-term wear resistance.

[0014] In a specific feasible embodiment, the mass ratio of the flaky graphene modified by dodecyl silane coupling agent to the flaky graphene modified by octadecyl silane coupling agent is 1:(1 - 1.1).

[0015] By adopting the above technical solutions, at this mass ratio, the interpenetration of flaky graphene and the shielding effect on the core layer are good, and the obtained zirconia coating silicon carbide material has good long-term wear resistance.

[0016] In a specific feasible embodiment, the high-temperature sintering includes the following steps: keeping the temperature at 800 - 1000 °C for 3 - 3.5 hours, and then raising the temperature to 2000 - 2200 °C and keeping the temperature for 3 - 4 hours.

[0017] By adopting the above technical solutions, the sintering is sufficient, and the obtained material has high strength and good wear resistance.

[0018] In a specific feasible implementation, the current of high-temperature thermal spraying is 400 A and the voltage is 65 V.

[0019] By adopting the above technical solution, the thermal spraying effect is good, the obtained coating is flat and dense, the interlayer connection strength is high, and the wear resistance performance is good.

[0020] In a specific feasible implementation, the powder feeding speed of high-temperature thermal spraying is 3 - 4 r / min, and the powder feeding air pressure is 6.5 - 7 atm.

[0021] Preferably, the powder feeding speed of high-temperature thermal spraying is 3.6 - 3.7 r / min, and the powder feeding air pressure is 6.6 - 6.7 atm.

[0022] By adopting the above technical solution, the thermal spraying effect is good, the obtained coating is flat and dense, the interlayer connection strength is high. At the same time, perhaps at this powder feeding speed and air pressure, the modified flaky graphene not only forms a more reasonable distribution on the surface of the obtained material due to different acceleration magnitudes during the thermal spraying process, but also forms a certain orientation arrangement. Therefore, the modified flaky graphene achieves better protection for the core material, further improving the long-term wear resistance performance of the obtained material.

[0023] In summary, the present application has the following beneficial effects: 1. By sequentially defining the raw material settings of the core layer, the first surface layer, and the second surface layer and performing high-temperature thermal spraying, the present application realizes better compatibility between layers, improves the connection strength, enhances the surface roughness of the core layer through the raw material settings, and enables the interlayer flaky graphene to interpenetrate, resulting in good protection of the core layer by the surface layer and good long-term wear resistance of the obtained material.

[0024] 2. By respectively modifying the flaky graphene in the first coating and the second coating with dodecyl silane coupling agent and octadecyl silane coupling agent, defining the mass ratio, and defining the powder feeding speed and powder feeding air pressure of high-temperature thermal spraying, the present application better adjusts the distribution of raw materials in the layer structure and the orientation of flaky graphene, further enhancing the protection effect on the core layer and extending the service life of the obtained material. Specific Embodiments

[0025] To further assist in understanding the technical solution of the present invention, several specific embodiments are provided to describe the technical solution of the present invention more specifically. All these described embodiments are only partial embodiments of the present invention, not all; the embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The following embodiments are further descriptions of the present invention, and the present invention is not limited thereto.

[0026] In the embodiments of the present application, the components of the preparation examples refer to the components obtained by the method of the preparation examples. Unless otherwise specified, experimental reagents are all conventional commercially available brands or obtained by conventional preparation processes. Among them, dodecylsilane coupling agent CAS: 3069-21-4, octadecylsilane coupling agent CAS: 3069-42-9, epoxy group silane CAS: 2530-83-8, the average particle size of large silicon carbide is 1 mm, and the average particle size of small silicon carbide is 0.05 mm.

[0027] Preparation Example Preparation Example 1: Dodecylsilane Coupling Agent Modified Flaky Graphene S1: Add 5 g of flaky graphene and 3 g of dodecylsilane coupling agent to 200 g of 50 vt% ethanol aqueous solution, stir evenly, adjust the pH to 6, heat to 75 °C and stir for 2 hours, centrifuge, wash with ethanol and deionized water 3 times in sequence, and dry to obtain dodecylsilane coupling agent modified flaky graphene.

[0028] Preparation Example 2: Octadecylsilane Coupling Agent Modified Flaky Graphene S1: Add 5 g of flaky graphene and 3 g of octadecylsilane coupling agent to 200 g of 50 vt% ethanol aqueous solution, stir evenly, adjust the pH to 6, heat to 75 °C and stir for 2 hours, centrifuge, wash with ethanol and deionized water 3 times in sequence, and dry to obtain octadecylsilane coupling agent modified flaky graphene.

[0029] Preparation Example 3: Epoxy Group Silane Coupling Agent Modified Flaky Graphene S1: Add 5 g of flaky graphene and 3 g of epoxy group silane coupling agent to 200 g of 50 vt% ethanol aqueous solution, stir evenly, adjust the pH to 6, heat to 75 °C and stir for 2 hours, centrifuge, wash with ethanol and deionized water 3 times in sequence, and dry to obtain epoxy group silane coupling agent modified flaky graphene.

[0030] Preparation Example 4: Dodecylsilane Coupling Agent Modified Large Silicon Carbide S1: Add 5 g of large silicon carbide and 3 g of dodecylsilane coupling agent to 200 g of 50 vt% ethanol aqueous solution, stir evenly, adjust the pH to 6, heat to 75 °C and stir for 2 hours, centrifuge, wash with ethanol and deionized water 3 times in sequence, and dry to obtain dodecylsilane coupling agent modified large silicon carbide. Example

[0031] Example 1: This example contains the following raw materials by mass: Core layer: 300 g of large silicon carbide, 150 g of small silicon carbide, 10 g of alumina, 50 g of magnesia, 50 g of zirconia, 30 g of silica, 20 g of tricresyl phosphate; The first coating comprises raw materials with the following masses: 400 g of zirconia, 150 g of small silicon carbide, and 50 g of flaky graphene; The second coating comprises raw materials with the following masses: 400 g of zirconia, 250 g of polytetrafluoroethylene, and 120 g of flaky graphene.

[0032] The preparation comprises the following steps: Mix the core layer raw materials evenly, dry them, press them into shape, keep them at 900 °C for 3 hours, raise the temperature to 2100 °C and keep them sintered for 3 hours to obtain the core layer. Mix the first coating and second coating raw materials evenly respectively, and then spray them onto the surface of the core layer at high temperature in sequence. The current is 400 A, the voltage is 65 V, the powder feeding speed is 3 r / min, the powder feeding air pressure is 7 atm, and spray until the thickness of the first coating is 3 mm and the thickness of the second coating is 1.5 mm to obtain the high wear-resistant zirconia coating silicon carbide material.

[0033] Example 2: This example contains raw materials with the following masses: Core layer: 460 g of large silicon carbide, 200 g of small silicon carbide, 10 g of alumina, 50 g of magnesia, 50 g of zirconia, 30 g of silicon dioxide, and 10 g of tricresyl phosphate; The first coating comprises raw materials with the following masses: 400 g of zirconia, 150 g of large silicon carbide, and 120 g of flaky graphene; The second coating comprises raw materials with the following masses: 400 g of zirconia, 250 g of polytetrafluoroethylene, and 50 g of flaky graphene.

[0034] The preparation comprises the following steps: Mix the core layer raw materials evenly, dry them, press them into shape, keep them at 900 °C for 3 hours, raise the temperature to 2100 °C and keep them sintered for 3 hours to obtain the core layer. Mix the first coating and second coating raw materials evenly respectively, and then spray them onto the surface of the core layer at high temperature in sequence. The current is 400 A, the voltage is 65 V, the powder feeding speed is 3 r / min, the powder feeding air pressure is 7 atm, and spray until the thickness of the first coating is 3 mm and the thickness of the second coating is 1.5 mm to obtain the high wear-resistant zirconia coating silicon carbide material.

[0035] Example 3: This example contains raw materials with the following masses: Core layer: 420 g of large silicon carbide, 200 g of small silicon carbide, 30 g of alumina, 30 g of magnesia, 30 g of zirconia, 30 g of silicon dioxide, and 20 g of tricresyl phosphate; The first coating comprises raw materials with the following masses: 300 g of zirconia, 170 g of small silicon carbide, and 80 g of flaky graphene; The second coating comprises raw materials with the following masses: 450 g of zirconia, 300 g of polytetrafluoroethylene, and 120 g of flaky graphene.

[0036] The preparation comprises the following steps: Mix the core layer raw materials evenly, dry them, press them into shape, keep them at 900 °C for 3 hours, raise the temperature to 2100 °C and keep them sintered for 3 hours to obtain the core layer. Mix the raw materials of the first coating and the second coating evenly respectively, and successively spray them onto the surface of the core layer at high temperature. The current is 400 A, the voltage is 65 V, the powder feeding speed is 3 r / min, the powder feeding air pressure is 7 atm, and spray until the thickness of the first coating is 3 mm and the thickness of the second coating is 1.5 mm to obtain the high wear-resistant zirconia coating silicon carbide material.

[0037] Example 4: This example contains raw materials with the following masses: Core layer: 420 g of large silicon carbide, 200 g of small silicon carbide, 30 g of alumina, 30 g of magnesia, 30 g of zirconia, 30 g of silica, and 20 g of tricresyl phosphate; The first coating comprises raw materials with the following masses: 300 g of zirconia, 170 g of small silicon carbide, and 80 g of flaky graphene; The second coating comprises raw materials with the following masses: 300 g of zirconia, 170 g of small silicon carbide, and 80 g of flaky graphene.

[0038] The preparation comprises the following steps: Mix the core layer raw materials evenly, dry them, press them into shape, keep them at 900 °C for 3 hours, raise the temperature to 2100 °C and keep them sintered for 3 hours to obtain the core layer. Mix the raw materials of the first coating and the second coating evenly respectively, and successively spray them onto the surface of the core layer at high temperature. The current is 400 A, the voltage is 65 V, the powder feeding speed is 3 r / min, the powder feeding air pressure is 7 atm, and spray until the thickness of the first coating is 3 mm and the thickness of the second coating is 1.5 mm to obtain the high wear-resistant zirconia coating silicon carbide material.

[0039] Example 5: This example contains raw materials with the following masses: Core layer: 420 g of large silicon carbide, 200 g of small silicon carbide, 30 g of alumina, 30 g of magnesia, 30 g of zirconia, 30 g of silica, and 20 g of tricresyl phosphate; The first coating comprises raw materials with the following masses: 300 g of zirconia, 170 g of large silicon carbide, and 80 g of flaky graphene; The second coating comprises raw materials with the following masses: 450 g of zirconia, 300 g of polytetrafluoroethylene, and 120 g of flaky graphene.

[0040] The preparation comprises the following steps: Mix the core layer raw materials evenly, dry them, press them into shape, keep them at 900 °C for 3 hours, heat up to 2100 °C and keep them sintered for 3 hours to obtain the core layer. Mix the raw materials of the first coating and the second coating evenly respectively, and then spray them onto the surface of the core layer at high temperature in sequence. The current is 400 A, the voltage is 65 V, the powder feeding speed is 3 r / min, and the powder feeding air pressure is 7 atm. Spray until the thickness of the first coating is 3 mm and the thickness of the second coating is 1.5 mm to obtain a high wear-resistant zirconia coating silicon carbide material.

[0041] Example 6: This example contains raw materials with the following masses: Core layer: 420 g of large silicon carbide, 200 g of small silicon carbide, 30 g of alumina, 30 g of magnesia, 30 g of zirconia, 30 g of silica, 20 g of tricresyl phosphate; The first coating includes raw materials with the following masses: 300 g of zirconia, 170 g of small silicon carbide, 80 g of dodecylsilane coupling agent modified flaky graphene prepared in Preparation Example 1; The second coating includes raw materials with the following masses: 450 g of zirconia, 300 g of polytetrafluoroethylene, 120 g of octadecylsilane coupling agent modified flaky graphene prepared in Preparation Example 2.

[0042] The preparation includes the following steps: Mix the core layer raw materials evenly, dry them, press them into shape, keep them at 900 °C for 3 hours, heat up to 2100 °C and keep them sintered for 3 hours to obtain the core layer. Mix the raw materials of the first coating and the second coating evenly respectively, and then spray them onto the surface of the core layer at high temperature in sequence. The current is 400 A, the voltage is 65 V, the powder feeding speed is 3 r / min, and the powder feeding air pressure is 7 atm. Spray until the thickness of the first coating is 3 mm and the thickness of the second coating is 1.5 mm to obtain a high wear-resistant zirconia coating silicon carbide material.

[0043] Example 7: This example contains raw materials with the following masses: Core layer: 420 g of large silicon carbide, 200 g of small silicon carbide, 30 g of alumina, 30 g of magnesia, 30 g of zirconia, 30 g of silica, 20 g of tricresyl phosphate; The first coating includes raw materials with the following masses: 300 g of zirconia, 170 g of small silicon carbide, 100 g of dodecylsilane coupling agent modified flaky graphene prepared in Preparation Example 1; The second coating includes raw materials with the following masses: 450 g of zirconia, 300 g of polytetrafluoroethylene, 100 g of octadecylsilane coupling agent modified flaky graphene prepared in Preparation Example 2.

[0044] The preparation includes the following steps: Mix the core layer raw materials evenly, dry them, press them into shape, keep them at 900 °C for 3 hours, heat up to 2100 °C and keep them sintered for 3 hours to obtain the core layer. Mix the raw materials of the first coating and the second coating evenly respectively, and then spray them onto the surface of the core layer at high temperature in sequence. The current is 400 A, the voltage is 65 V, the powder feeding speed is 3 r / min, the powder feeding air pressure is 7 atm, and the thickness of the first coating sprayed is 3 mm and the thickness of the second coating is 1.5 mm to obtain the high wear-resistant zirconia coating silicon carbide material.

[0045] Example 8: This example contains the following raw materials by mass: Core layer: 420 g of large silicon carbide, 200 g of small silicon carbide, 30 g of alumina, 30 g of magnesia, 30 g of zirconia, 30 g of silica, 20 g of tricresyl phosphate; The first coating includes the following raw materials by mass: 300 g of zirconia, 170 g of small silicon carbide, 80 g of octadecylsilane coupling agent modified flaky graphene prepared in Preparation Example 2; The second coating includes the following raw materials by mass: 450 g of zirconia, 300 g of polytetrafluoroethylene, 120 g of dodecylsilane coupling agent modified flaky graphene prepared in Preparation Example 1.

[0046] The preparation includes the following steps: Mix the core layer raw materials evenly, dry them, press them into shape, keep them at 900 °C for 3 hours, heat up to 2100 °C and keep them sintered for 3 hours to obtain the core layer. Mix the raw materials of the first coating and the second coating evenly respectively, and then spray them onto the surface of the core layer at high temperature in sequence. The current is 400 A, the voltage is 65 V, the powder feeding speed is 3 r / min, the powder feeding air pressure is 7 atm, and the thickness of the first coating sprayed is 3 mm and the thickness of the second coating is 1.5 mm to obtain the high wear-resistant zirconia coating silicon carbide material.

[0047] Example 9: This example contains the following raw materials by mass: Core layer: 420 g of large silicon carbide, 200 g of small silicon carbide, 30 g of alumina, 30 g of magnesia, 30 g of zirconia, 30 g of silica, 20 g of tricresyl phosphate; The first coating includes the following raw materials by mass: 300 g of zirconia, 170 g of small silicon carbide, 80 g of dodecylsilane coupling agent modified flaky graphene prepared in Preparation Example 1; The second coating includes the following raw materials by mass: 450 g of zirconia, 300 g of polytetrafluoroethylene, 120 g of epoxy group silane coupling agent modified flaky graphene prepared in Preparation Example 3.

[0048] The preparation includes the following steps: Mix the core layer raw materials evenly, dry them, press them into shape, keep them at 900 °C for 3 hours, heat up to 2100 °C and keep them sintered for 3 hours to obtain the core layer. Mix the raw materials of the first coating and the second coating evenly respectively, and then spray them onto the surface of the core layer at high temperature successively. The current is 400 A, the voltage is 65 V, the powder feeding speed is 3 r / min, and the powder feeding air pressure is 7 atm. Spray until the thickness of the first coating is 3 mm and the thickness of the second coating is 1.5 mm to obtain the high wear-resistant zirconia coating silicon carbide material.

[0049] Example 10: This example contains raw materials with the following masses: Core layer: 420 g of large silicon carbide, 200 g of small silicon carbide, 30 g of alumina, 30 g of magnesia, 30 g of zirconia, 30 g of silica, 20 g of tricresyl phosphate; The first coating includes raw materials with the following masses: 300 g of zirconia, 170 g of small silicon carbide, 80 g of dodecylsilane coupling agent modified flaky graphene prepared in Preparation Example 1; The second coating includes raw materials with the following masses: 450 g of zirconia, 300 g of polytetrafluoroethylene, 120 g of dodecylsilane coupling agent modified large silicon carbide prepared in Preparation Example 4.

[0050] The preparation includes the following steps: Mix the core layer raw materials evenly, dry them, press them into shape, keep them at 900 °C for 3 hours, heat up to 2100 °C and keep them sintered for 3 hours to obtain the core layer. Mix the raw materials of the first coating and the second coating evenly respectively, and then spray them onto the surface of the core layer at high temperature successively. The current is 400 A, the voltage is 65 V, the powder feeding speed is 3 r / min, and the powder feeding air pressure is 7 atm. Spray until the thickness of the first coating is 3 mm and the thickness of the second coating is 1.5 mm to obtain the high wear-resistant zirconia coating silicon carbide material.

[0051] Example 11: This example contains raw materials with the following masses: Core layer: 420 g of large silicon carbide, 200 g of small silicon carbide, 30 g of alumina, 30 g of magnesia, 30 g of zirconia, 30 g of silica, 20 g of tricresyl phosphate; The first coating includes raw materials with the following masses: 300 g of zirconia, 170 g of small silicon carbide, 100 g of dodecylsilane coupling agent modified flaky graphene prepared in Preparation Example 1; The second coating includes raw materials with the following masses: 450 g of zirconia, 300 g of polytetrafluoroethylene, 100 g of octadecylsilane coupling agent modified flaky graphene prepared in Preparation Example 2.

[0052] The preparation includes the following steps: Mix the core layer raw materials evenly, dry them, press them into shape, keep them at 900 °C for 3 hours, heat up to 2100 °C and keep them sintered for 3 hours to obtain the core layer. Mix the raw materials of the first coating and the second coating evenly respectively, and then spray them onto the surface of the core layer at high temperature in sequence. The current is 400 A, the voltage is 65 V, the powder feeding speed is 3.6 r / min, the powder feeding air pressure is 6.6 atm, and the thickness of the first coating is sprayed to 3 mm and the thickness of the second coating is 1.5 mm to obtain the high wear-resistant zirconia coating silicon carbide material.

[0053] Comparative example Comparative example 1: This comparative example contains the following raw materials by mass: Core layer: 450 g of large silicon carbide, 10 g of alumina, 50 g of magnesia, 30 g of silica, 20 g of tricresyl phosphate; The first coating includes the following raw materials by mass: 400 g of zirconia, 150 g of small silicon carbide, 50 g of flaky graphene; The second coating includes the following raw materials by mass: 400 g of zirconia, 250 g of polytetrafluoroethylene, 120 g of flaky graphene.

[0054] The preparation includes the following steps: Mix the core layer raw materials evenly, dry them, press them into shape, keep them at 900 °C for 3 hours, heat up to 2100 °C and keep them sintered for 3 hours to obtain the core layer. Mix the raw materials of the first coating and the second coating evenly respectively, and then spray them onto the surface of the core layer at high temperature in sequence. The current is 400 A, the voltage is 65 V, the powder feeding speed is 3 r / min, the powder feeding air pressure is 7 atm, and the thickness of the first coating is sprayed to 3 mm and the thickness of the second coating is 1.5 mm to obtain the high wear-resistant zirconia coating silicon carbide material.

[0055] Comparative example 2: This comparative example contains the following raw materials by mass: Core layer: 300 g of large silicon carbide, 150 g of small silicon carbide, 10 g of alumina, 50 g of magnesia, 50 g of zirconia, 30 g of silica, 20 g of tricresyl phosphate; The first coating includes the following raw materials by mass: 550 g of small silicon carbide, 50 g of flaky graphene; The second coating includes the following raw materials by mass: 550 g of small silicon carbide, 50 g of flaky graphene.

[0056] The preparation includes the following steps: Mix the core layer raw materials evenly, dry them, press them into shape, keep them at 900 °C for 3 hours, heat up to 2100 °C and keep them sintered for 3 hours to obtain the core layer. Mix the raw materials of the first coating and the second coating evenly respectively, and spray them onto the surface of the core layer at high temperature in sequence. The current is 400 A, the voltage is 65 V, the powder feeding speed is 3 r / min, the powder feeding air pressure is 7 atm, and the thickness of the first coating is sprayed to 3 mm and the thickness of the second coating is 1.5 mm to obtain the high wear-resistant zirconia coating silicon carbide material.

[0057] Performance detection test Test 1: Refer to the standard GB / T 18301-2001: Test method for room temperature abrasion resistance of refractories, Detect the weight loss 1 (g) of the high wear-resistant zirconia coating silicon carbide materials prepared in each example and comparative example. The test results are summarized in Table 1.

[0058] Test 2: Immerse the high wear-resistant zirconia coating silicon carbide materials prepared in each example and comparative example in hot water at 100 °C for 120 hours, take them out, dry them at 100 °C, and then refer to the standard GB / T 18301-2001: Test method for room temperature abrasion resistance of refractories, and repeat to detect the weight loss 2 (g) of the high wear-resistant zirconia coating silicon carbide materials prepared in each example and comparative example. Calculate according to the reference change rate = (weight loss 2 - weight loss 1) / weight loss 1 × 100%, and the test results are summarized in Table 1.

[0059] Table 1 Weight loss 1 (g) Change rate (%) Example 1 8.2 21.1 Example 2 8.4 21.3 Example 3 8.0 20.8 Example 4 12.4 23.5 Example 5 10.0 24.2 Example 6 6.1 16.4 Example 7 5.7 13.8 Example 8 7.2 18.4 Example 9 7.7 18.8 Example 10 12.8 26.9 Example 11 4.1 10.1 Comparative Example 1 19.2 33.1 Comparative Example 2 16.7 45.0 Combined with Examples 1-5, Comparative Examples 1-2 and Table 1, the present application realizes higher interlayer connection strength by sequentially defining the raw material settings of the core layer, the first surface layer, and the second surface layer and performing high-temperature spraying, has a good protection effect on the core layer, and the prepared material has good long-term wear resistance.

[0060] Combined with Example 3, Examples 6-11 and Table 1, the present application modifies the flaky graphene of the first coating and the second coating with dodecyl silane coupling agent and octadecyl silane coupling agent respectively, defines the mass ratio, and defines the powder feeding speed and powder feeding air pressure of high-temperature spraying, better adjusts the distribution of raw materials in the layer frame and the orientation of flaky graphene, further improves the protection effect on the core layer, and extends the service life of the prepared material.

[0061] This specific embodiment is only an explanation of the present application, and it is not a limitation of the present application. 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 they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A high wear-resistant zirconia-coated silicon carbide material, characterized in that: It includes a core layer and a coating layer. The core layer is made of raw materials in the following parts by weight: 45 - 85 parts of silicon carbide, 1 - 5 parts of aluminum oxide, 1 - 5 parts of magnesium oxide, 1 - 5 parts of zirconium oxide, 1 - 5 parts of silicon dioxide, and 1 - 3 parts of additives. The silicon carbide includes large silicon carbide and small silicon carbide with a mass ratio of (2 - 2.3):

1. The particle size of the large silicon carbide is 0.1mm - 2mm, and the particle size of the small silicon carbide is 0.01 - 0.08mm; the coating layer uses zirconium oxide as the matrix raw material.

2. The high wear-resistant zirconia-coated silicon carbide material according to claim 1, wherein: The coating layer includes a first coating layer close to the core layer and a second coating layer far from the core layer. The first coating layer is made of raw materials in the following parts by mass: 20 - 40 parts of zirconium oxide, 15 - 20 parts of small silicon carbide, and 5 - 12 parts of flaky graphene. The second coating layer is made of raw materials in the following parts by mass: 40 - 50 parts of zirconium oxide, 25 - 35 parts of polytetrafluoroethylene, and 5 - 12 parts of flaky graphene.

3. A method for preparing a high wear-resistant zirconia-coated silicon carbide material according to any one of claims 1-2, characterized in that: It includes the following steps: Mix the raw materials of the core layer evenly, dry them, press them into shape, and sinter them at high temperature to obtain the core layer. Mix the raw materials of the first coating layer and the second coating layer evenly respectively, and then spray them onto the surface of the core layer at high temperature in sequence to obtain the zirconium oxide - coated silicon carbide material.

4. The preparation method of the high wear-resistant zirconia-coated silicon carbide material according to claim 3, characterized in that: The thickness of the first coating layer is 0.1 - 10mm, and the thickness of the second coating layer is 0.1 - 3mm.

5. The preparation method of the high wear-resistant zirconia-coated silicon carbide material according to claim 3, characterized in that: The flaky graphene in the first coating layer is flaky graphene modified by dodecyl silane coupling agent, and the flaky graphene in the second coating layer is flaky graphene modified by octadecyl silane coupling agent.

6. The preparation method of the high wear-resistant zirconia-coated silicon carbide material according to claim 5, characterized in that: The mass ratio of the flaky graphene modified by dodecyl silane coupling agent to the flaky graphene modified by octadecyl silane coupling agent is 1:(1 - 1.1).

7. The preparation method of the high wear-resistant zirconia-coated silicon carbide material according to claim 3, characterized in that: The high - temperature sintering includes the following steps: Keep the temperature at 800 - 1000°C for 3 - 3.5 hours, and then raise the temperature to 2000 - 2200°C and keep it for 3 - 4 hours.

8. The preparation method of the high wear-resistant zirconia-coated silicon carbide material according to claim 3, characterized in that: The current of the high - temperature spraying is 400A, and the voltage is 65V.

9. The preparation method of the high wear-resistant zirconia-coated silicon carbide material according to claim 6, characterized in that: The powder feeding speed of the high - temperature spraying is 3 - 4r / min, and the powder feeding air pressure is 6.5 - 7atm.