激光熔覆Ti基WC增强复合涂层的裂纹研究  

Research on Cracks of Ti-based WC Reinforced Composite Coating by Laser Cladding

作　　者：匡建新[1] 汪新衡[1] 秦小平[1] 朱航生 

机构地区：[1]湖南工学院机械工程系,湖南衡阳421002 [2]衡阳丰顺车桥有限公司产品部,湖南衡阳421002

出　　处：《热加工工艺》2010年第14期110-112,119,共4页Hot Working Technology

基　　金：湖南省科技计划基金资助项目(05JT1017);湖南工学院重点科研基金资助项目(HGZ0601)

摘　　要：研究了激光熔覆Ti基WC增强复合涂层的开裂行为。结果表明:涂层裂纹主要有熔覆层内的弥散穿晶裂纹,源于激光熔覆层边缘的粗大沿晶裂纹,WC颗粒上的扩展裂纹。开裂是由于熔覆层与金属基体两种材料之间极高的温度梯度,以及它们的熔点、热膨胀系数、弹性模量及导热系数等物理性能参数的差异很大所致。同时开裂倾向还受激光工艺参数、涂层合金粉的配比以及强化相的形状、大小等因素的影响。The cracking behavior of Ti-based WC reinforced composite coating by laser cladding was studied.The results show that the cracks of composites are mainly dispersed with diffuse transgranular cracks in the cladding layer,thick intergranular cracks from the edge of laser cladding layer of coarse and extended cracks on WC particles.The cracking is due to physical performance parameters such as the extreme high temperature gradient,different melting,thermal expansion coefficients,modulus and thermal conductivity between the matrix and the coating.At the same time,the cracking trend is affected by the laser cladding process parameters,the alloy powders content,and the shape and size of the reinforced phases.

关 键 词：激光熔覆 裂纹 TI基合金 WC金属陶瓷 热膨胀系数 

分 类 号：TG174.44[金属学及工艺—金属表面处理]