Effects of Shot Peening on Fatigue Property of New Aluminum Alloy 7055-T7751

7055-T7751 aluminum alloy surfaces were strengthened by ceramic shot peening. The influences of shot peening intensity and coverage ratio on the surface residual stress,roughness,damage and hardness and fatigue property of 7055-T7751 aluminum alloy were studied using X-ray diffraction analysis,surface profile measurement,scanning electron microscopy(SEM) and microhardness testing. The results show that the fatigue property of the Al alloy can be obviously improved in the optimized shot peening process. But the strengthening effect was not in a simple monotonic enhancement with the increase of shot peening intensity and coverage ratio. when the shot peening parameters were in a reasonalbe range,the alloy could have good comprehensive surface integrity and the best fatigue property. The optimized shot peening parameters were shot peening intensity of 0.15 mm and coverage ratio of 100%. The fatigue life of 7055-T7751 aluminum alloy treated with the optimized parameters was 2.7 times higher than that of the alloy substrate.