Abstract
Self designed cold spray equipment was installed in the laboratory and deposition behavior of sprayed individual metallic particles on the substrate surface was fundamentally investigated. As a preliminary experiment, pure Cu particles were sprayed on mirror polished stainless steel and Al alloy substrate surfaces. Process parameters changed systematically were particles diameter, working gas, gas pressure, gas temperature and substrate temperature, and effect of these parameters on the flattening or adhesive behavior of an individual particle was precisely investigated. Deposition ratio on substrate surface was also evaluated on these parameters. From the results obtained, it was quite noticeable that the higher substrate temperature brought about higher deposition rate of Cu particles even under the condition with particles temperature kept at room temperature. This tendency was promoted more effectively by using helium instead of air or nitrogen as a working gas. Both higher velocity and temperature of the particles sprayed are the necessary conditions for the higher deposition ratio in the cold spraying. However, instead of particles heating, substrate heating may bring about the equivalent effect for the deposition of the particles. This finding is quite new and has never been reported.
