中文摘要：

采用脉冲电弧放电沉积法在SiC-C／C复合材料表面制备了方石英型磷酸铝（C-AlPO4）抗氧化涂层。借助x射线衍射、扫描电子显微镜和静态等温氧化实验对涂层的晶相组成、显微结构和抗氧化性能进行了表征与测试。研究了脉冲频率对C-AlPO4涂层显微结构的影响，分析了C-AlPO4涂层在1773K下的氧化行为。结果表明：200-2000Hz范围内，当脉冲电压为1000Hz时制得的C—AIPO。涂层致密均匀，在1773K氧化120h后质量损失仅为0．5％，具有较好的抗氧化性能。C-AlPO4涂层在1773K下的氧化能力下降主要是由于长时间氧化后偏磷酸盐玻璃层不能及时有效填补涂层中的缺陷，涂层试样在高温下产生了较多贯穿性孔洞导致的。

英文摘要：

A C-AlPO4 anti-oxidation coating was prepared on SiC pre-coated C/C composites by pulsed arc discharge deposition. The phase compositions, microstructures and anti-oxidation properties of the as-prepared coatings were characterized by X-ray diffraction, scanning electron microscopy and isothermal oxidation test. The influence of impulse frequency on the microstructure was investi- gated. Results show that the dense and homogeneous C-A1PO4 coating was achieved when the impulse frequency reaches 1 000 Hz. The as-prepared coatings exhibit excellent anti-oxidation property, which could effectively protect C/C composites from oxidation at 1 773 K in air for 120h with a mass loss of 0.5%. The anti-oxidation capability decrease of the coating at 1 773 K is due to the generation of cross-holes in the coating, which leads to the failure of self-curing by the metaphosphate glass layer after long time of oxidation.