Enhancing plain fatigue strength in aluminum alloys through shot peening: Experimental investigations and a strain energy density interpretation

This study addresses the complex interplay of shot peening-induced effects on the fatigue strength of high-strength aluminum alloys. The inherent poor fatigue properties of aluminum alloys, particularly exacerbated in components manufactured through additive processes, pose significant challenges. Shot peening, a recognized surface treatment, proves effective in enhancing fatigue resistance through mechanisms such as compressive residual stresses, work hardening, and microstructural changes. However, optimizing shot peening and developing accurate fatigue prediction models remain challenging due to the intricate and unclear contributions of the individual mechanisms. In this investigation, five distinct shot peening treatments were employed to emphasize specific effects. Experimental results, analyzed through a strain energy density approach, shed light on the crucial role of compressive residual stresses in maximizing fatigue strength. This comprehensive exploration contributes with valuable insights for designing shot peening treatments to optimize the fatigue performance of high-strength aluminum alloys.