激光冲击中应力状态和显微组织变化对金属疲劳性能影响  

Effects of stress state and microstructure change on metallic fatigue performance under laser shock processing

作　　者：李伟[1] 李应红[1] 汪诚[1] 何卫锋[1] 周鑫[1] 

机构地区：[1]空军工程大学工程学院,西安710038

出　　处：《航空精密制造技术》2009年第3期37-39,48,共4页Aviation Precision Manufacturing Technology

基　　金：国防预研基金项目(513270103)

摘　　要：从应力状态与显微组织的变化两个方面分析了激光冲击强化改善金属疲劳性能的机理。首先研究了残余应力的作用,认为激光冲击强化产生的残余压应力降低了零部件承受的平均应力水平。然后利用位错理论分析了金属经激光冲击强化引起的显微组织变化,认为激光冲击强化在材料表层产生了大量位错、晶界以及亚晶界等缺陷,这些缺陷阻碍了位错的移动,使金属得到强化。The mechanism of laser shock processing(LSP) was analyzed from metallic stress state and microstructure change.It was found that the residual compressive stress induced by LSP can lower the average stress level.And LSP can create a lot of defects in the metal,such as dislocation,grain boundary and sub-boundary,etc,which can clag the movements of dislocation,and strengthen the metal.LSP can improve the microstructure of material and impress residual compressive stress into surfaces of metal work piece,suppress the initiation and expansion of cracks,so this treatment extends the metallic fatigue life time.

关 键 词：激光技术 激光冲击强化 残余应力 显微组织 疲劳 

分 类 号：TG665[金属学及工艺—金属切削加工及机床]