包埋-化学气相沉积两步法制备ZrC涂层的结构与抗烧蚀性能  

Microstructure and ablation properties of ZrC coating prepared by two-step technique of pack cementation and CVD

作　　者：吴敏[1] 李国栋[1] 熊翔[1] 杨钢宜 

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《粉末冶金材料科学与工程》2013年第6期827-834,共8页Materials Science and Engineering of Powder Metallurgy

基　　金：国家重点基础研究发展规划(973计划)资助项目(2011CB605805);国家自然科学基金创新群体项目(51021063)

摘　　要：采用先包埋、然后化学气相沉积(CVD)的复合工艺,在石墨材料表面制备ZrC涂层,并对其进行氧乙炔焰烧蚀试验。借助X射线衍射(XRD)和扫描电镜(SEM)分析烧蚀前后涂层的微观组织形貌及相组成,研究涂层的抗烧蚀机理。结果表明:包埋-CVD两步法制备的ZrC涂层,包埋层具有双层结构,外层多孔、内层致密;CVD层表面呈凸胞状形貌,为柱状晶结构;包埋多孔层与CVD层相互嵌入,形成机械互锁结构,增强了涂层间的界面结合强度。30 s氧乙炔焰烧蚀试验表明:ZrC涂层具有很好的结构稳定性和良好的抗热震性能;烧蚀产物为单斜型ZrO2,质量烧蚀率和线烧蚀率分别为1.50×10-3 g/s和0.47×10-3 mm/s,涂层具有良好的高温抗烧蚀性能和抗冲刷性能。The ZrC coating was prepared by a two-step technique of pack cementation and chemical vapor deposition （CVD） processes, and investigated by oxyacetylene torch flame test. The surface morphology and phase composition of the coating before and after ablation were studied by SEM and XRD analysis, and then the ablation mechanisms were investigated. The results show that in the as-prepared coating, the coating prepared by pack cementation method has a double structure with the outer porous layer and the inner dense layer;the CVD layer forms columnar crystal structure with smooth arch surface;the porous layer and the CVD layer are mutually embedded to form a mechanical interlocking structure, thus enhancing the interface bonding strength between the coatings. The oxyacetylene torch flame test results show that the ZrC coating remains good structural stability after 30 s ablation and shows excellent thermal shock resistance. The ablation product is monoclinic ZrO2;the mass and linear ablation rates of coated sample are 1.50×10-3 g/s and 0.47×10-3 mm/s, respectively, shows good ablation resistance and anti-erosion resistance.

关 键 词：包埋 化学气相沉积 ZrC涂层 显微结构 抗烧蚀性能 

分 类 号：TB332[一般工业技术—材料科学与工程]