激光冲击抗金属疲劳断裂的激光参数优化试验研究

描述了激光冲击参数对２０２４－Ｔ６２铝合金疲劳寿命的影响．当激光脉宽为５０ｎｓ时．试件表面产生有害的热损伤，疲劳寿命无显著性差别．当激光脉宽为１３ｎｓ时．试件表面未产生足够的塑性变形，疲劳寿命提高幅度不大．当激光脉宽为３０ｎｓ时，试件表面形成微凹致密的光亮冲击区．疲劳寿命获得大幅度提高，在９５％的置信度下．激光冲击试件的中值疲劳寿命是来冲击试件的４．２～８．１倍．

Study of Laser Parameters Optimum of Laser Shocking Against Fatigue and Fracture of Metal

The influence of laser shock-processing (LSP) parameeters on the fatigue life of aluminum alloy 2024-T62 is described. If the duration of a laser is 50 ns, there is a heat damage on the LSP area of the specimen surface, and there is no improvemet on the fatigue life of metal. If the duration is 13 ns, there is no apparent plastic deformation, and there is a little improvement on the fatigue life. If the duration is 30 ns, on the surface of the specimen there is a densified hollow LSP area that is very shiny, and the fatigue life is increased greatly. With 95% confidence, the fatigue life of LSP specimen is 4.2～8.1 times larger than the unprocessed specimen.