Microstructure evolution of cold-sprayed coating during deposition and through post-spraying heat treatment  

作　　者：LI Chang-jiu LI Wen-ya 

机构地区：[1]State Key Laboratory for Mechanical Behavior of Materials, Xi''an Jiaotong University, Xi''an 710049, China State Key Laboratory for Mechanical Behavior of Materials, Xi''an Jiaotong University, Xi''an 710049, China

出　　处：《中国有色金属学会会刊：英文版》2004年第z1期49-54,共6页Transactions of Nonferrous Metals Society of China

基　　金：Project (50171052) supported by the National Natural Science Foundation of China; Project supported by the Doctoral Foundation of Xi'an Jiaotong University, China

摘　　要：The microstructural features of cold-sprayed coatings were investigated using Cu, Ti and Zn feedstocks by optical microscopy, scanning electron microscopy and transmission electron microscopy to reveal the microstructure evolution mechanisms in cold spray. Four typical effects including tamping, refinement, impact-induced fusion and annealing were examined on microstrueture. It is found that the microstructure of cold spray coating is remarkably influenced by spray materials. Ti coatings consist of evident porous layer and Cu coatings present a limited porous layer only near the surface. It is clear that the successive tamping effect and dynamic refinement of grains significantly influence the microstructure evolution of cold-sprayed coating. The tamping effect leads to the densification of porous coating layer gradually and the refinement effect leads to the formation of fine microstructure. It is considered that the large difference in the formation of porous layer is attributed to the dynamic impact pressure and hardenability of materials. It is also found that the impact-induced fusion during deposition of Zn coating can also modify the interfacial microstructure between particles in cold spray coating. Moreover, the nanocrystalline phase can be formed at the interfaces among particles resulting from the localized melting of the interfaces and tamping effect. Furthermore, the annealing treatment can modify the microstructure and property of a cold-sprayed coating.

关 键 词：cold SPRAYING COATING microstructure evolution annealing treatment 

分 类 号：TG174[金属学及工艺—金属表面处理]