利用激光冲击强化提高均压孔结构的疲劳寿命

Fatigue-Life Improvement of Symmetrical Pressure Hole by Laser Shock Processing

研究了用激光冲击强化的方法提高均压孔部位疲劳寿命的可行性。使用流水约束层和铝箔涂层,利用波长为1 064 nm,脉宽为20 ns,能量为35 J,光斑直径为5 mm的YAG激光器对试样进行了激光冲击强化处理。实验结果表明,该方法可以有效提高均压孔部位疲劳寿命。利用扫描电镜对试样断口进行了观察和分析,并对疲劳寿命提高机制进行了讨论。

To improve the fatigue life of the symmetrical pressure hole, a new laser shock processing technology is investigated. Symmetrical pressure hole specimens are processed with YAG laser. The laser peening parameters are as follows： the wavelength of 1 064 nm; the pulse duration of 20 ns and output energy of 35 J. The laser is focused on a spot of 5 mm. Results indicate that the fatigue life is effectively increased by laser shock processing. The fractographs of the specimen are analyzed by scanning electron microscopy（SEM）, and the improvement mechanism of the fatigue life is discussed.