Analysis of Thermal History and Residual Stress in Cold Sprayed Coatings

It is generally believed that residual stresses in cold spray coatings are caused by particle impact and deformation and are hence predominantly compressive, as opposed to thermal spraying where thermal effects, particularly solidification, play the lead role. This study aims to provide a preliminary review of this notion through finite element analysis, distortion measurements on copper-coated steel, and the consideration of thermal history. The dimensions and elastic properties of the coating and substrate are key factors in the study along with heat input. Based on the review, a simple model is proposed to predict the final state of residual stress and distortion in flat surfaces coated by cold spraying.