The influence of process parameters on deposition characteristics of a soft/hard composite coating in kinetic spray process

In kinetic spray processes, the non-uniformity of resultant composite coatings is generally caused by the difference in critical velocity and deposition efficiency between the components of a mixed feedstock. In the present paper, the effects of process parameters, such as feed rate, spray distance, and particle velocity, on the compositional variation between the mixed feedstock and resultant composite coating have been investigated. The results showed that the high diamond fraction in the coating can be achieved using a low feed rate, intermediate spray distance, and high impact particle velocity. The possibility of impact between hard brittle diamond particles is the main factor affecting the diamond fraction in the coating. Although the deposition efficiency, diamond fraction, and bond strength of the coating increase with particle velocity, a slight decrease of cohesive strength between diamond particle and bronze base was also observed. (c) 2007 Elsevier B.V. All rights reserved.