Li Xiang, He Weifeng, Luo Sihai, Nie Xiangfan, Tian Le, Feng Xiaotai, Li Rongkai
Science and Technology on Plasma Dynamics Laboratory, Air Force Engineering University, Xi'an 710038, China.
Institute of Aeronautics Engine, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
Materials (Basel). 2019 Apr 24;12(8):1343. doi: 10.3390/ma12081343.
The residual stress introduced by laser shock peening (LSP) is one of the most important factors in improving metallic fatigue life. The shock wave pressure has considerable influence on residual stress distribution, which is affected by the distribution of laser energy. In this work, a titanium alloy is treated by LSP with flat-top and Gaussian laser beams, and the effects of spatial energy distribution on residual stress are investigated. Firstly, a 3D finite element model (FEM) is developed to predict residual stress with different spatial energy distribution, and the predicted residual stress is validated by experimental data. Secondly, three kinds of pulse energies, 3 J, 4 J and 5 J, are chosen to study the difference of residual stress introduced by flat-top and Gaussian laser beams. Lastly, the effect mechanism of spatial energy distribution on residual stress is revealed.
激光冲击强化（LSP）引入的残余应力是提高金属疲劳寿命的最重要因素之一。冲击波压力对残余应力分布有相当大的影响，而残余应力分布受激光能量分布的影响。在这项工作中，用平顶和高斯激光束对钛合金进行激光冲击强化处理，并研究空间能量分布对残余应力的影响。首先，建立三维有限元模型（FEM）来预测不同空间能量分布下的残余应力，并用实验数据对预测的残余应力进行验证。其次，选择3J、4J和5J三种脉冲能量来研究平顶和高斯激光束引入的残余应力差异。最后，揭示了空间能量分布对残余应力的作用机制。
