Effect of the shot peening on the deformation of Al alloy component

The surface of Al-based alloy thin-walled component is treated by the shot peening (SP). After the SP, structure deformation and recovery can be observed due to natural aging, which causes the structural instability of component. In this study, the effect of SP on the recovery is investigated with residual stress evolution, surface microhardness and surface roughness. The influence of SP coverage percentage has been studied. The recovery level is associated with the shot coverage percentage, and the recovery ratio of components is up to 25% after the 100% coverage and down to 3% after the 400% coverage. The study shows the coverage percentage is a crucial parameter that makes the surface of materials get adequate plastic deformation and the grain refining. The experiments find that the multiple coverage percentages can improve the surface microhardness and resist plastic deformation, and guarantee the shape stability of the components.