Impacting Behavior of Large Oxidized Copper Particles in Cold Spraying

In the previous studies, it has been experimentally demonstrated that surface oxide films of metallic particles have significant influence on the deposition efficiency, microstructure and properties of cold sprayed coatings. To clearly reveal the underlying mechanism, this study focuses further on the effect of particle oxidation on its deposition behavior with the intendedly oxidized Cu particles having an average size of about 81μm. The oxidized Cu powder was deposited by cold spraying with respect to the single impacts and coating deposition. In addition, the rebounded copper particles were collected for morphology analysis compared to the adhered particles. Results show that the deposition efficiency of the oxidized Cu particles is much lower than that of the unoxidized Cu powder. The thick oxide film extremely prohibits the bonding of particles. In addition, the clearance of interface oxide inclusions by plastic deformation of particles was also observed.