重熔等离子喷涂层的裂纹形成原因与对策分析

Study on crack formation mechanism of remelted plasma sprayed coating

采用等离子喷涂技术,在45号钢基体上制备了镍基涂层,然后对涂层进行了钨极氩弧(TIG)重熔处理,之后采用扫描电镜对重熔涂层进行了组织形貌观察,并对裂纹进行了EDS能谱分析。结果表明,重熔电流对重熔层裂纹倾向有明显影响,当电流为50 A,重熔层成型良好,内部没有裂纹,当电流增加到60 A和90 A时,裂纹越来越显著;此外,EDS能谱结果表明,裂纹中存在较多的B,Si元素;在此基础上,分析了裂纹的形成原因并提出了解决措施。

Ni based coating was prepared on 45# steel substrate by plasma spraying. After the remelting treatment of coating by TIG welding,the microstructure of the remelted coating was observed by scanning electron microscope( SEM),and the EDS spectrum of the crack was analyzed. The results show that the remelting current has an obvious influence on the crack tendency of the remelted layer. At the current of 50 A,the remelting layer is well formed and there is no crack. However,the current increases to 60 A and 90 A,the crack becomes more and more serious. In addition,the EDS spectrum shows that there are many B and Si elements in the crack. On this basis,the causes of cracks were analyzed and the solutions were proposed.