Evaluating the effect of deposition conditions on the local wear resistance of cold sprayed stainless steel coatings

Abstract

The useful service life of metallic structures is affected by the exposure to the meteorological phenomena. In this sense, the continuous impact of particles suspended in the atmosphere could produce microscratches on the surfaces of these components, generating several wear degradations. These damaged surfaces can be repaired in order to increase their service life, avoiding component replacement and reducing the environmental impact. Recently, coatings deposition by cold spray has been revealed as a promising strategy for repairing damaged components. Therefore, the main objective of this work is focused on the analysis of wear resistance against micro-scratching in metallic coatings. For this purpose, 316L stainless steel powders were deposited onto low carbon steel S355J2 by cold spray, varying the pressure and temperature of the propellant gas. Nanoindentation tests were carried out to determine hardness and elastic modulus. The wear rates and the friction coefficients were measured through microscratch tests using a Berkovich tip. The wear mechanisms were analysed evaluating the scratch grooves in the scanning electron microscope. Finally, the relationship between hardness and wear rate was determined.