To investigate the improvement in vibration fatigue and the strengthening mechanism of laser shock peening, a nanosecond laser was used to strengthen the 2024-T351 aluminium alloy. Accordingly, the microstructure, residual stress, nanohardness and surface roughness of the treated alloy were measured. Subsequently, the vibration fatigue damage and fatigue life were evaluated, and the vibration fracture morphology was observed. The results showed that the grains in the peened surface were refined. A residual stress of −141 MPa and a nanohardness of 3.1 GPa were obtained by laser shock peening. Based on the relationship between the peened microstructure and fracture morphology, it was deduced that an increase in the grain boundaries led to a lower crack initiation rate and a higher crack initiation life. The compressive residual stress decreased the crack growth rate and increased the crack growth life. Therefore, laser shock peening increases the total vibration fatigue life by about 63.5%.

为了研究振动疲劳的改善和激光冲击强化的机理，使用纳秒激光来增强2024-T351铝合金。因此，测量了处理过的合金的微观结构，残余应力，纳米硬度和表面粗糙度。随后，评估振动疲劳损伤和疲劳寿命，并观察振动断裂形态。结果表明，喷丸处理后的表面晶粒细化。通过激光冲击喷丸获得-141 MPa的残余应力和3.1 GPa的纳米硬度。根据喷丸组织与断裂形态之间的关系，可以推断出晶界的增加导致较低的裂纹萌生率和较高的裂纹萌生寿命。压缩残余应力降低了裂纹的生长速率并延长了裂纹的寿命。因此，激光冲击喷丸使总的振动疲劳寿命增加了约63.5％。