对7055-T7751新型铝合金表面进行了陶瓷丸喷丸强化处理,采用X射线衍射仪、表面轮廓仪、扫描电子显微镜、显微硬度计等研究了喷丸强度、喷丸覆盖率等工艺参数对铝合金表面残余应力场、表面粗糙度、表面损伤及表面加工硬化和疲劳性能的影响。结果表明:优化工艺参数下的喷丸强化能够显著提高该铝合金的疲劳性能,并不是喷丸强度或喷丸覆盖率越高强化效果越好,而是存在合理的喷丸强化参数范围,在优化条件下铝合金可以获得良好的综合表面完整性,疲劳断裂抗力最高;确定的优喷丸参数为喷丸强度0.15 mm,覆盖率100%,以此参数强化处理的7055-T7751铝合金的疲劳寿命是基材的2.7倍。

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.