硅灰石涂层开裂的原位观察及粉末粒度对其断裂的影响  

In-situ observation of cracking in wollastonite coatings and effect of powder size on fracture

作　　者：王鲁斌[1] 王卫泽[1] 陈雨帆[1] 轩福贞[1] 

机构地区：[1]华东理工大学承压系统与安全教育部重点实验室,上海200237

出　　处：《焊接学报》2014年第3期57-60,116,共4页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51275172);973计划资助项目(2012CB625104)

摘　　要：涂层断裂分析对研究涂层的失效机制、优化制备工艺、指导涂层设计具有重要作用.通过对等离子喷涂硅灰石涂层在电镜下进行加载,原位观察其裂纹扩展路径.并通过对涂层断裂韧性及表面和断面形貌的分析,探讨涂层粒度对涂层裂纹扩展的影响.结果表明,裂纹的扩展方向主要受外加应力方向的影响,涂层中原有孔隙,包括大气孔、层内裂纹和层间未结合对开裂过程具有一定的引导作用.随粉末粒度降低,涂层的断裂路径更加曲折,断裂韧度增加.Fracture analysis of coatings has an important role on the investigation of coating's failure mechanism,the optimization of the processing parameters and the design. The fracture of plasma sprayed wollastonite coatings was observed in-situ by using a scanning electron microscope( SEM) during the tapered double cantilever beam( TDCB) specimens were pulled open. Additionally,the effect of powder size on the coating's fracture toughness is investigated based on the observation of the microstructure,fracture morphology and cracking propagation of coatings. It was found that the cracking path was mainly influenced by the applied stress. The original pores in the coatings,including the large pores,cracks and non-bounded interfaces could guide the cracking somewhat. The fracture toughness of coatings increased and fracture paths were more curved with the decreasing of powder size

关 键 词：涂层断裂 原位观察 硅灰石 等离子喷涂 

分 类 号：TG174.45[金属学及工艺—金属表面处理]