论文部分内容阅读
采用料浆熔烧法,在航天发动机用铌钨合金Nb521-1表面制备高温抗氧化防护涂层,通过两次熔烧依次制备底层和面层,得到硅化物复合涂层。利用SEM及EDS分析涂层的微观形貌和元素含量,对涂层1 700℃高温抗氧化性能和室温~1 600℃热循环性能进行测试,并初步探讨涂层失效机理。结果表明,制备的复合涂层和基体之间通过互扩散形成扩散层,达到冶金结合;涂层在1 700℃下可连续工作22h,室温~1 600℃热循环测试完成了1 124次。在高温条件下,复合涂层可有效阻止外界氧向基体进一步扩散,对基体形成了良好的保护。
The slurry melting method was used to prepare the high-temperature anti-oxidation protective coating on the surface of niobium-tungsten alloy Nb521-1 used in aerospace engine. The bottom layer and the surface layer were sequentially prepared through two steps of sintering to obtain the silicide composite coating. The microstructure and elemental content of the coating were analyzed by SEM and EDS. The oxidation resistance of the coating at 1 700 ℃ and the thermal cycling at room temperature ~ 1 600 ℃ were tested, and the failure mechanism of the coating was also discussed. The results show that the prepared composite coating and substrate are interdiffused to form the diffusion layer to achieve the metallurgical bonding. The coating can work continuously at 1 700 ℃ for 22h and the thermal cycling test at room temperature ~ 1 600 ℃ for 1 124 times. Under the condition of high temperature, the composite coating can effectively prevent the outside oxygen from diffusing to the matrix, and forms a good protection to the matrix.