A novel surface strengthening technique for enhancing fatigue properties of 6061 Al alloy

Abstract

A new surface spinning rolling (SR) strengthening technique was developed to enhance the fatigue properties of 6061 Al alloy. The traditional shot peening (SP) process can strengthen the sample's surface, but it increases surface damage, which seriously hinders the improvement of fatigue performance. However, the SR process not only introduces a high residual compressive stress and a hardened layer on the sample surface but also remarkably lowers the surface roughness. Moreover, the SR treatment formed a gradient microstructure on the surface layer of 6061 Al alloy, effectively postponing the initiation and propagation of fatigue cracks. Fatigue experiments demonstrate that after SR treatment, the fatigue strength of 6061 Al alloy increases by 17.9 %, from 223 MPa to 263 MPa. This study demonstrates the significant advantages by the SR process in producing high fatigue-resistant Al alloy components.