多次激光喷丸作用下TC4钛合金的疲劳性能及微裂纹扩展预测模型  

Fatigue Properties and Crack Growth Prediction Model of TC4 Titanium Alloy Subjected to Multiple Laser Shot Peening

作　　者：周晓刚[1] 纪飞飞 ZHOU Xiaogang;JI Feifei(Suzhou Chien-Shiung Institute of Technology,Suzhou 215411,China;School of Mechanical Engineering,Jiangsu University,Zhenjiang 212013,China)

机构地区：[1]苏州健雄职业技术学院,苏州215411 [2]江苏大学机械工程学院,镇江212013

出　　处：《机械工程材料》2021年第5期100-104,共5页Materials For Mechanical Engineering

基　　金：苏州健雄职业技术学院2019年度校科学基金资助项目(自然科学类)(2019QNZK008);太仓市基础研究计划(面上)项目(TC2020JC13);浙江省基础公益研究计划项目(LGF18E090001)。

摘　　要：对TC4钛合金板进行不同次数激光喷丸处理,再进行高周疲劳试验,研究了其疲劳性能及断裂机理;基于残余压应力及晶界介微观尺寸对微裂纹扩展的阻滞作用,采用抑制参数、张开应力强度因子、残余应力强度因子对Paris公式进行修正,建立了激光喷丸处理后疲劳微裂纹扩展预测模型,并进行了试验验证。结果表明:随着喷丸次数增加,TC4钛合金的疲劳强度增大,疲劳寿命延长,断裂方式由脆性断裂向韧性断裂转变;疲劳微裂纹预测模型预测得到的疲劳寿命与试验值的相对误差小于10%,说明模型准确。TC4 titanium alloy plates were subjected to laser shot peening for different times and then subjected to high cycle fatigue tests. The fatigue properties and fracture mechanism of the alloy were studied. Considering the retardation effect of the residual compressive stress and the mesoscopic size of grain boundaries on the microcrack growth, the suppression parameter, open stress intensity factor and residual stress intensity factor were introduced to modify the Paris formula. Then a prediction model for fatigue microcrack growth after laser shot peening was established and verified by experiments. The results show that with the increase of the number of shot peening, the fatigue strength and fatigue life of the TC4 titanium alloy increased, and the fracture mode changed from brittle fracture to ductile fracture. The relative errors of the fatigue life predicted by the fatigue microcrack prediction model and the test results were less than 10%, indicating that the model was accurate.

关 键 词：激光喷丸 疲劳性能 残余压应力 裂纹扩展预测模型 

分 类 号：TG39[金属学及工艺—金属压力加工]