采用2.5 mm厚的铝合金LYl2(2024)T62、1.5 mm厚高强钢以及1.7 mm厚高温合金薄板制作成紧凑拉伸试件,对预制裂纹延长线进行三次搭接(光斑直径6 mm)激光冲击处理,进行裂纹扩展速率试验并与未处理的试件进行对比,由于激光冲击处理产生的强化效应在裂纹扩展路径上存在区域差别,所以裂纹扩展速率无法进行Paris公式拟合,但在整体上能大大降低裂纹扩展速率.

In this paper, compact tension(CT) specimens of 2024T62 sheet with thickness of 2.5 mm, a superalloy with thickness of 1.5 mm and a high-strength steel sheet with thickness of 1.7 mm were treated by laser shock processing, three spots with diameter of 6 mm overlapped along the extension line of precut crack. The fatigue crack growth rates of laser shock processed specimens were compared with those without LSP, the results show that effects of laser shock strengthening have much difference along the crack growth line, the fatigue growth rates can't be fitted by the Paris formula, but decreased in whole.