Cold spraying: A low temperature variant of thermal spray techniques to deposit metallic materials

Cold spraying is a novel material deposition process in which micron size particles are accelerated to supersonic velocity on to a metallic substrate to obtain thick and dense coatings. Unlike other thermal spray coatings, the bonding mechanism is completely different. In conventional thermal spray techniques, melting and solidification upon impact dominates the bonding mechanism. In cold spraying, Plastic deformation induced adiabatic shear instability governs the bonding process in which adiabatic temperature rise, plastic strain at interface and flow stress collapse play a crucial role. Variety of material including pure metals, alloys, composites and cermets have been deposited using cold spraying for variety of applications. In this article, a brief introduction about the bonding mechanism and potential applications of cold spraying is being discussed.