Investigation of impact behavior of cold-sprayed large annealed copper particles and characterization of coatings

In this research, the large gas-atomized copper powder was selected as the feedstock. Some powder was annealed in a vacuum circumstance to avoid the effect of grain boundaries on the high velocity impact behavior of particles during cold spraying. The annealed Cu powder was deposited by cold spraying with respect to the single impacts and coating deposition under certain gas condition. In addition, the rebounded copper particles were collected for morphology analysis compared to the adhered particles. The results show that the average size of the rebounded particles is apparently increased compared with the starting powder because of the rebounding of larger particles and intensive plastic deformation of the rebounded particles. For the deposited particles, obvious plastic deformation causes a higher hardness to the coating. It is found that the rebounded particles have also experienced large deformation and shear instability at the impact interfaces.