On the Application of Cold Spray Coating in Repairing Damaged Parts: Study of Cavity Filling and Fatigue Behavior

Cold spray is a novel and promising technology to obtain surface coating. More recently, repair and restoring damaged parts have also emerged among the potential application of cold spray deposition. The significance of the research in this topic is self evident, especially in case of large components very demanding both as regards manufacturing time and as concern cost. Notwithstanding the several technological advantages with respect to other processes, cold spray diffusion is somewhat limited by the limited knowledge about the mechanical properties of the cold sprayed materials and in particular, their fatigue behavior. In the present investigation, artificial defect has been introduced on Al 2024 fatigue specimen. Both small and extended defects representing local and vast material loss are studied. The ability of the cold spray method to properly fill the defect is investigated using scanning electron microscopy of the cross section of the defect. Repaired parts are then subjected to axial fatigue test. A critical discussion on the ability of cold spray to repair damaged parts and to maintain acceptable fatigue strength is conducted.