摘要
为解决激光熔覆Stellite 6涂层的裂纹与气孔问题,利用尾吹保护的特殊工艺,以半导体激光器为光源,氩气为保护气,同轴送粉的方式熔覆制备了合金涂层复合材料。并利用光学显微镜、扫描电镜、X射线衍射仪和显微硬度计分别对尾吹保护工艺下激光熔覆Stellite 6合金涂层的成型性、显微组织和硬度进行测试分析。结果表明:在15L/min的尾吹气保护下,熔覆所得合金涂层成型良好;熔覆过程中的气孔、热裂纹的缺陷得到抑制;层间、结合处涂层的微观组织得到了细化,晶体生长形态由树枝晶转变为等轴晶;多层多道涂层间的硬度分布均匀;晶粒生长方向发生改变,熔覆层组织与β相Co基本保持一致。由此证明,引入尾吹保护工艺能够改善激光熔覆Stellite 6合金涂层的组织性能。
To eliminate porosities and cracks of the Stellite 6 coating, makeup argon gas protection was applied during the laser cladding process. Microstructure and hardness of the coating were observed and analyzed by optical metalgrapic （OM）, Xray diffractometer and vicker microhardness tester. The results show that under the protection of makeup gas （flow rate 15 L/min）, fine grain can be obtained with a low dilution rate, caused by high cooling rate, and lower thermal stress; at the interface, interdendritic zones will be formed between the layers, improving mechanical properties of the coating; the grain grows along the direction （200）, consistent with βCo; for multilayer conditions, the hardness is more uniform with the makeup gas protection.
出处
《中国表面工程》
EI
CAS
CSCD
北大核心
2014年第2期52-56,共5页
China Surface Engineering
基金
国际科技合作专项基金(2009DFB50350)
