表征经过激光喷丸处理前后得到的CuNiCrSi合金硬度、疲劳破坏产生的断口形貌、表面残余应力与疲劳寿命, 分析CuNiCrSi合金表面经过激光喷丸强化处理后发生的疲劳性能变化。研究结果表明: 激光喷丸处理实现了硬度提高, 从表面往基体硬度逐渐减小, 能量为2 J比能量为5 J情况下形成的硬度影响层厚度小。以2 J与5 J的激光能量进行喷丸得到的试样残余应力都在表面处达到最大残余应力, 随表面距离的增大残余应力不断降低。经激光喷丸处理引起试样表面裂纹源发生内移使试样表面达到更大的疲劳极限。疲劳断口扩展区生成了二次裂纹, 当激光能量提高后, 获得更大的裂纹长度与深度。各试样都形成了明显的等轴韧窝结构。

The hardness, fracture morphology, surface residual stress and fatigue life of CuNiCrSi alloy after laser shot peening were characterized, and the fatigue performance changes of CuNiCrSi alloy after laser shot peening were analyzed.The results show that the hardness is improved by laser shot peening, and the hardness decreases gradually from the surface to the substrate. The hardness of the affected layer is smaller when the energy is 2 J than 5 J.The residual stress of samples obtained by shot peening with the laser energy of 2 J and 5 J reaches the maximum residual stress at the surface, which decreases with the increase of the surface distance.The laser shot peening causes the surface crack source to shift inward and causes the surface to reach a greater fatigue limit.Secondary cracks are generated in the fatigue fracture growth zone, and larger crack length and depth are obtained when the laser energy is increased.All the samples formed obvious isometric dimple structure.