Analysis of fatigue resistance improvements via surface severe plastic deformation

Numerical simulations have been performed to analyze the individual contributions of the nanocrystalline surface layer, residual compressive stresses, and a work-hardened surface region to the improved fatigue limit of a nickel alloy subjected to the surface nanocrystallization and hardening (SNH) treatment. The contributions of the nanocrystalline surface layer and work-hardened surface region have been separated from that of residual compressive stresses. The study suggests that the nanocrystalline surface layer and work-hardened surface region play a significant role in enhancing the fatigue limit of the SNH-processed nickel alloy. In contrast, less contribution is provided by residual compressive stresses.