Abstract
Cold Gas Dynamic Spray is a line of sight, high rate material deposition process that uses a supersonic flow to accelerate small particles (micron size powder) above a material dependent critical velocity. When the particles impact the substrate, they plastically deform and bond to form a coating. The objective of this research is to investigate the influence of the particle mass flow rate on the properties of coatings sprayed using the Cold Spray process. Varying the mass flow rate at which the feedstock particles are fed into the carrier gas stream can change the thickness of the coating. It was shown that poor coating quality (peeling) was not a result of flow saturation but instead, excessive particle bombardment per unit area on the substrate. This can be overcome by increasing the relative velocity between the substrate and the spraying nozzle. The results are dense coatings, even at higher powder mass flow rates.
