硅钼含量对C/C复合材料SiC-MoSi_2涂层结构和高温抗氧化性能的影响  

Effect of Si/Mo ratio on microstructure and high-temperature antioxidation property of SiC-MoSi_2 coating for carbon/carbon composites

作　　者：侯党社[1] 李克智[1] 李贺军[1] 史小红[1] 魏剑[1] 

机构地区：[1]西北工业大学超高温结构复合材料国防科技重点实验室,西安710072

出　　处：《固体火箭技术》2008年第3期283-287,共5页Journal of Solid Rocket Technology

基　　金：国家"973"资助项目(2006CB600908)

摘　　要：采用两步包埋法在C/C复合材料表面制备SiC-MoSi2抗氧化复合涂层,通过恒温氧化实验以及X射线衍射分析、扫描电镜观察,研究了包埋粉料中硅钼含量对复合涂层微观结构和高温抗氧化性能的影响。结果表明,随着包埋粉料中硅钼比的减小,涂层的厚度和致密性先增加后减小,硅钼质量比为6∶1时所制备的复合涂层具有较大的厚度和较为致密的结构,且MoSi2含量相对较高,体现出优良的抗氧化和抗热震性能,在1 500℃氧化87.3 h和经过9次1 500℃室温急冷急热后,带有该涂层的C/C试样失重仅为3.22%。穿透性裂纹的形成是长时间氧化后涂层失效的主要原因。The SiC-MoSi2 antioxidation coating for carbon/carbon composite surface was prepared by two-step embedding method. The effects of Si/Mo ratio in embedded powders on the microstructure and high-temperature antioxidation property of the composite coating were investigated by means of XRD, SEM and isothermal oxidation test. The results show that with the decrease of Si/Mo ratio, the thickness and compactness of the coating first increase, then decrease. The prepared composite coating is of certain thickness, compact structure and higher content of MoSi2 when the mass ratio of Si to Mo is 6：1. The composite coating has excelletion antioxidation property and thermal-shock resistance. After oxidized for 87.3 h at 1 500 ℃ and treated from 1 500 ℃ to room temperature for 9 times, C/C samples with the coating has only 3.22% weight loss. The main reason of coating failure is the formation of some penetration cracks after long-time oxidation.

关 键 词：C/C复合材料 SiC-MoSi2抗氧化复合涂层 抗氧化性能 抗热震性能 

分 类 号：TF123.3[冶金工程—粉末冶金]