摘要
文摘采用刷涂法在C/SiC复合材料表面制备Mo-Si抗氧化涂层,研究涂层的微观结构、氧化性能和热震性能。结果表明,涂层中存在微裂纹等缺陷,物相组成为MoSi2、SiO2、SiC和Si。1 400℃氧化时,微裂纹等缺陷迅速愈合。单层Mo-Si涂层试样经5 h氧化后,失重率高达5.90%,贯穿裂纹是涂层失效的主要原因。三层Mo-Si涂层试样经140 h氧化后,失重率仅为1.37%,失重速率为3.80×10-5g/(cm2.h)。在1 400℃100℃的热震过程中,涂层保持完整,热震50次的失重率为0.34%。经25次和50次热震后,涂层试样的弯曲强度保持率分别为90.30%和74.56%。三层涂层具有优异的抗氧化和抗热震性能,这与涂层的制备工艺和结构密切相关。
Mo - Si coatings are prepared on the surface of C/SiC composites by slurry painting, The microstructure, oxidation behavior and thermal shock property are investigated. The results show that the coating is composed of MoSi2, SiO2, SiC and Si and defects such as cracks are observed. However, they are quickly self-sealed when oxidized at 1 400℃. For single Mo -Si coating, penetrating cross cracks mainly caused the failure. After 5 h oxidation in air at 1 400℃, weight loss of the coated samples is 5.90%. For three-layer Mo - Si coating, weight loss and weight loss rate after 140 h oxidation are 1.37% and 3.80×10^-5 g/（ cm^2·h）, respectively. During thermal cycling between 1 400℃ and 100℃, three-layer Mo - Si coating keeps intact. After 25 and 50 thermal cycles, the flexural strength retention rate is 90.30% and 74.56%, respectively and the weight loss is 0.34% after 50 thermal cycles. Three-layer Mo - Si coating shows excellent anti-oxidation ability and thermal shock resistance, which are attributed to the manufacturing method and microstructure of the coating.
出处
《宇航材料工艺》
CAS
CSCD
北大核心
2007年第6期39-43,共5页
Aerospace Materials & Technology
