Surface characteristics and fatigue performance of warm shot peened wrought magnesium alloy Mg–9Gd–2Y

Abstract

The surface characteristics and fatigue performance of the warm shot peened Mg–9Gd–2Y alloys were investigated. Compared to conventional shot peening (SP) at room temperature, warm shot peening (WSP) at 240°C induces higher subsurface hardening and larger maximum compressive residual stress in the subsurface of the specimens. The optimum Almen intensity of WSP is 0·15 mm N, whereas it is 0·10 mm N for SP. The main reason is that the surface of warm shot peened specimen is more plastically deformed but less damaged at the optimum Almen intensity due to the increase in plastic deformation ability of the tested alloys at elevated temperature. The fatigue strength of the tested alloy at 10⁷ cycles is increased from 125 to 175 MPa by optimum SP and to 185 MPa by optimum WSP.

Keywords:

• Warm shot peening
• Fatigue
• Surface roughness
• Microhardness
• Magnesium alloy

Acknowledgements

We gratefully acknowledge the support by the National Natural Science Foundation and Bao steel of China (grant nos. U1360104 and 50901045) and by the Shanghai Rising Star Program (A type, grant no. 12QH1401200).