激光冲击表面处理及疲劳性能有限元分析

Finite Element Analysis of Laser Peening Surface Treatment and Fatigue Properties

表面微晶化是提高材料疲劳寿命的主要方法之一。钛合金金属构件抗疲劳处理为应用背景,研究了TC4钛合金激光冲击表面微晶化处理方法,有限元分析其表面组织和疲劳寿命。结果表明:激光冲击处理后,在材料表面形成了一层厚度约为10μm的细晶组织,材料疲劳寿命提高9—10倍,疲劳断裂开裂源的位置为激光冲击难于冲击到的边角地区和应力集中区域。

Surface grain refine is one of main ways to improve the fatigue life of material.In order to improve the fatigue life of titanium alloy in aviation industry,a method of refining the surface grain by laser peenning is introduced.The surface and fatigue life treated by laser peenning are analyzed with finite element method.The results show that there is a small grain layer at the surface and the thickness is about 10 μm.The improvement of fatigue life is about 9~10 times.The origin of crack appears at the area which is difficult to peen.