The importance of Optimizing Nozzle dimensions for cold spray process

Particle velocity is one of the most crucial parameter to determine coating’s properties in cold spray process, such as coating’s densification and bonding strength. To achieve a high particle velocity, the common way is to increase the working gas temperature or pressure, sometime using the extremely expensive helium gas. In this study, computational fluid dynamics method (CFD) was employ to optimize the nozzle dimension in order to improve particle velocity. Particle velocity was also measured with DPV-2000 to verify the simulation results. Furthermore, coatings were deposited by the nozzles with different dimension and their mechanical and electric properties were tested. The results show that the optimized nozzle benefited to improve the adhesive strength with substrate and electric properties of cold-sprayed coatings.