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以方石英型磷酸铝(C-AlPO4)粉体和莫来石粉体(3Al2O3·2SiO2)为原料,采用溶剂热电泳沉积方法在C/C-SiC复合材料表面制备C-AlPO4-莫来石复合抗氧化涂层。利用X线衍射、扫描电子显微镜对复合涂层的物相组成、显微结构进行表征。研究沉积时间对C-AlPO4-莫来石涂层显微结构的影响,讨论涂层的沉积动力学,并对涂层的抗氧化性能进行测试。结果表明:当沉积5~25 min时,沉积时间对涂层的显微结构影响较大,当沉积15 min时,涂层致密均匀;涂层的沉积量随着溶剂热温度的升高而增加;单位面积沉积量与时间的二次方根之间符合线性关系,并得到沉积活化能为24.39 kJ/mol;与包埋法制备的SiC内涂层相比,溶剂热电泳沉积法制备的C-AlPO4-莫来石/SiC复合涂层具有较好的抗氧化性能,复合涂层可在1 773 K静态空气中有效保护C/C复合材料300 h,氧化后质量损失率仅为1.26%。
C-AlPO4-mullite was prepared on the surface of C / C-SiC composites by using CSP-AlPO4 powder and mullite powder (3Al2O3 · 2SiO2) as raw materials by solvothermal electrophoretic deposition Composite anti-oxidation coating. The phase composition and microstructure of the composite coating were characterized by X-ray diffraction and scanning electron microscopy. The effect of deposition time on the microstructure of C-AlPO4-mullite coating was studied. The deposition kinetics of the coating and the oxidation resistance of the coating were tested. The results show that the deposition time has a significant effect on the microstructure of the coatings when deposited for 5 ~ 25 min. When the deposition time is 15 min, the coatings are dense and uniform. The coating deposition increases with the increase of the solvothermal temperature ; The linear relationship between the deposition amount per unit area and the square root of time was obtained and the activation energy of deposition was 24.39 kJ / mol. Compared with the SiC inner coating prepared by embedding method, the C -AlPO4-mullite / SiC composite coating has good oxidation resistance, the composite coating can effectively protect the C / C composite material in 1 773 K static air for 300 h, and the mass loss rate after oxidation is only 1.26%.