Method for preparing carbon/carbon composite zirconium silicate/silicon carbide antioxidant coating

Abstract

The invention relates to a method for preparing a carbon/carbon composite zirconium silicate/silicon carbide antioxidant coating, which comprises the following steps: uniformly mixing silicon powder with graphite powder, thereby obtaining the powder A; uniformly mixing Al2O3 powder, Ta2O5 powder, WO3 powder and B2O3 powder, thereby obtaining powder B; mixing the powder A with the powder B, thereby obtaining the embedding powder C; placing a carbon/carbon sample into a graphite crucible, and adding the embedding powder C; sintering in a vertical vacuum furnace by taking argon as an protective atmosphere, thereby obtaining a carbon/carbon composite; adding zirconium silicate and iodine into isopropanol, thereby obtaining a suspension solution; placing the suspension solution into a water-heating kettle; selecting a graphite base as the anode of the water-heating kettle and the carbon/carbon composite with a silicon carbide transition layer as the cathode; sealing the water-heating kettle, placing the water-heating kettle into a microwave generator, and performing water-heating electrophoresis and electric-heating deposition; and after finishing the deposition, taking out the sample,and drying, thereby obtaining the carbon/carbon composite zirconium silicate/silicon carbide antioxidant coating. The reaction is once finished in the water-heating kettle, no post-heating treatment is required, the processing equipment is simple, the obtained zirconium silicate coating is compact and uniform, the reaction period is short and the cost is low.

Description

technical field [0001] The invention relates to a preparation method of a C / C composite material, in particular to a method for preparing a zirconium silicate / silicon carbide anti-oxidation coating of a carbon / carbon composite material by using a microwave hydrothermal electrophoretic deposition method. technical background [0002] Carbon / carbon (C / C) composites are one of the advanced material composites that can be used in high temperature environments. Due to the characteristics of low thermal expansion coefficient, low density, ablation resistance, corrosion resistance, stable friction coefficient, good thermal and electrical conductivity, high strength and high modulus of carbon / carbon composite materials, especially the mechanical properties do not decrease but increase with the increase of temperature. characteristics, so it is used in aviation, aerospace and civil industry. However, many of its above-mentioned properties can only be maintained in an inert atmospher...

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Problems solved by technology

Yttrium silicate (Y 2 Si 2 o 7 ) Y, Si, O theoretical substance ratio is 2: 2: 7, but because other impurities inevitably appear in the preparation process of yttrium silicate, it is difficult to obtain pure yttrium silicate [Wang Yaqin, Huang Jianfeng , Cao Liyun, Wu Jianpeng. Silicate Bulletin. 2009, 28, 255.]

Since commercially available aluminum phosphate raw materials are usually in the amorphous phase, in which C-AlPO 4 The oxidation resistance of aluminum phosphate is good, but aluminum phosphate needs to be heat-treated before the coating is prepared to convert the amorphous phase into C-AlPO 4 , so the preparation process is complicated [Yang Wendong, Huang Jianfeng, Cao Liyun, Xia Changkui. Journal of Silicates. 2009, 37, 1319.], the theoretical decomposition temperature of zirconium silicate is 1700 °C, has a very low oxygen permeability, and can be used at 1500 °C It exists stably for a long time in a high temperature environment and does not undergo phase change, so zirconium silicate is used as the outer coating material, which has the characteristics of low cost and good effect

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