激光冲击处理对TC4修复件疲劳裂纹扩展速率的影响  

Effect of Laser Shock Processing on Fatigue Crack Growth Rate of TC4 Repaired Parts

作　　者：葛茂忠 项建云[2] 汤洋 Ge Maozhong;Xiang Jianyun;Tang Yang(Department of Materials Engineering,Jiangsu University of Technology,Changzhou,Jiangsu 213001,China;School of Mechanical Engineering and Technology,Changzhou Vocational Institute of Light Industry,Changzhou,Jiangsu 213164,China)

机构地区：[1]江苏理工学院材料工程学院,江苏常州213001 [2]常州轻工职业技术学院机械工程与技术学院,江苏常州213164

出　　处：《激光与光电子学进展》2018年第7期330-337,共8页Laser & Optoelectronics Progress

基　　金：江苏省自然科学基金面上项目(BK20151171)

摘　　要：通过疲劳裂纹扩展实验,研究了激光冲击处理对TC4修复件疲劳裂纹扩展速率的影响,对比分析了激光冲击处理前后TC4修复件的表层残余应力、表面粗糙度和断口形貌的变化。结果表明,TC4修复件的激光修复区由β晶粒和沿晶界分布的α相组成,热影响区由等轴α晶粒和β转变组织组成。激光冲击处理TC4修复件物相的衍射峰半峰全宽较大,其表层的残余应力为压应力,表面的粗糙度增大。通过修正的七点递增多项式拟合法,获得了不同修复件的裂纹扩展速率方程。激光冲击TC4修复件的疲劳裂纹扩展速率小于未激光冲击的。By the fatigue crack growth experiment,the effect of laser shock processing（LSP）on fatigue crack growth rate of TC4 repaired parts is investigated and the changes of surface residual stress,surface roughness and fracture morphology of TC4 repaired parts before and after LSP are compared and analyzed.The experimental results indicate that,the laser repaired zone of TC4 repaired parts is composed ofβgrains andαphase which distributes along the grain boundaries,and the heat affected zone consists of equiaxedαgrains andβtransformation structure.After the LSP,the full width at half maximum of diffraction peaks is larger,the surface residual stress is compressive stress,and the surface roughness increases.Based on the modified seven-point incremental polynomial fitting method,the fatigue crack growth rate equations of different repaired parts are obtained.The fatigue crack growth rate of TC4 repaired parts with LSP is smaller than that without LSP.

关 键 词：激光技术 激光熔覆修复 激光冲击处理 TC4钛合金 残余应力 裂纹扩展速率 

分 类 号：TN249[电子电信—物理电子学]