高温喷丸强化Ti6Al4V合金的热力耦合数值模拟  

Thermo-Mechanical Coupled Simulation of Warm Shot Peening of Ti6Al4V Alloy

作　　者：王成 王龙[1] WANG Cheng;WANG Long(School of Mechanical Engineering, Anhui University of Science and Technology, Huainan 232001, China;Anhui Key Laboratory of Mine Intelligent Equipment and Technology, Anhui University of Science &Technology, Huainan232001, China)

机构地区：[1]安徽理工大学机械工程学院,淮南232001 [2]安徽理工大学矿山智能装备与技术安徽省重点实验室,淮南232001

出　　处：《中国表面工程》2019年第2期143-153,共11页China Surface Engineering

基　　金：国家自然科学基金(51705002);安徽省自然科学基金(1708085QE123);安徽理工大学青年重点项目(QN2018106)~~

摘　　要：发展一种连接喷丸强化与高温加载传热的热力耦合有限元方法,模拟高温喷丸强化Ti6Al4V合金的过程。首先建立一圆盘模型模拟待喷材料的高温加载传热过程。然后将圆盘模型的受热部分取出一小块建立对称胞元喷丸模型,并且将高温加载所致的温度场和热应力场通过解析场的方式导入到对称胞元喷丸模型,模拟高温喷丸强化过程。最后通过回弹计算获得稳定的残余应力场和温度场。创建4种模拟工况:常温喷丸、单独导入温度场的喷丸、单独导入热应力场的喷丸和高温喷丸,探究高温喷丸的残余压应力强化机理。结果表明:在常温环境下,对称胞元喷丸模型模拟的Ti6Al4V表层残余应力与试验结果具有很好的一致性。在高温加载作用下,随着热流密度的增加,受喷材料表层残余压应力有所减小,材料亚表层的残余压应力逐渐增大。影响高温喷丸强化的残余压应力的主要因素是高温加载所致的温度场,热应力场对残余压应力强化起次要作用。A thermo-mechanical coupled finite element method, by linking heat transfer to shot peening, was developed for simulation of warm shot peening of Ti6Al4V alloy. A disk-shape finite element model was first developed to simulate the heat transfer under different heat flux densities. The symmetrical cell model taken from the disk-shape finite element model was then developed to simulate the process of warm shot peening. With the method of analytical field, the temperature fields and thermal stress fields resulted from the simulation of heat transfer were imported into the symmetrical cell model. The stable residual stress and temperatures fields were obtained after the spring-back calculation of the peened material. Four modeling cases were designed to investigate the strengthening mechanism of compressive residual stress, including normal shot peening,warm shot peening and two cases of only introducing temperature fields and thermal stress fields. Results show that the residual stress predicted by the symmetrical cell model agrees well with the experimental data under the normal temperature.As the heat flux density increases, the surface compressive residual stresses decrease, while the compressive residual stresses in the subsurface increase. The simulation results show that the main factor influencing the warm shot peening-induced residual stresses is the temperature fields resulted from heat transfer, and the thermal stress fields play a secondary role.

关 键 词：高温喷丸强化 残余应力 传热分析 热力耦合 TI6AL4V合金 

分 类 号：TG668[金属学及工艺—金属切削加工及机床]