Effect of post-processing treatments on mechanical performance of cold spray coating – an overview

Abstract The main objective of this review is to study the effect of post-processing treatments on the mechanical performance of cold sprayed coatings. The cold spray (CS) process is an evolving technology for the rapid production of coatings at almost low temperatures, creating a thin, dense layer of coatings and a massive level of the additive manufacturing process with low-phase transition and less oxidization. In this process, powder particles are quickened by a process gas to supersonic velocity and impinge on the substrate, thereby establishing a higher adhesive bond between the substrate and the plastically deformed condition and eventually producing a deposition with the texture of the layer. However, the cohesive behaviour and metallurgical bonding is lower because of the lowest atomic diffusion among various splats of CS process with defects like pores, voids, and micro-cracks in the coating surface. It affects the properties of coating. In order to enhance the surface properties of coating, post-treatments are required. Heat treatment, friction stir processing, laser remelting, and shot peening are advanced treatments used to improve the performance of CS coatings. As a result, the mechanical, tribological, and electrochemical properties of post-treated samples are improved compared to coated samples.