Particle velocity and deposition efficiency in the cold spray process

Copper powder was sprayed by the cold gas-dynamic method. In-flight particl e velocities were measured with a laser two-focus system as a function of p rocess parameters such as gas temperature, gas pressure, and powder feed ra te. Mean particle velocities were uniform in a relatively large volume with in the plume and agreed with theoretical predictions. The presence of a sub strate was found to have no significant effect on in-flight particle veloci ties prior to impact. Cold-spray deposition efficiencies were measured on a luminum substrates as a function of particle velocity and incident angle of the plume. Deposition efficiencies of up to 95% were achieved, The critica l velocity for deposition was determined to be about 640 m/s for the system studied.