Improvement of Titanium Cold Spray Coating Adhesion by Shot Peening

Shot peening was applied to quenched and highly tempered C55 structural steel as a pretreatment to titanium coating cold spray deposition with the aim of improving the coating's adhesion during cyclic loading.Applying titanium cold spray directly onto the steel surface caused significant plastic deformation of the substrate, resulting in the creation of discontinuities on the coating/substrate interface.When shot peening was applied prior to the cold spraying, the work-hardened surface layer served as a more suitable substrate, avoiding the creation of major interface discontinuities.Fatigue resistance of the shot-peened specimens was improved by up to 20% and no coating delamination was observed in the regions of fatigue crack initiation and propagation.