激光冲击强化对钛合金疲劳寿命影响综述EI北大核心CSCD

对提升钛合金零件的疲劳强度,已有相关技术的试验研究,但缺乏对技术的系统介绍,阻碍了该技术的产业化应用。通过整理大量试验数据及其结果,就激光冲击强化对钛合金零件的疲劳特性的影响展开分析。简要介绍激光冲击强化技术的发展状况,分别从表面形貌、残余应力、微观组织、硬度、表面粗糙度等方面进行分析总结。结果发现,当激光脉冲能量为7 J时,材料塑性变形量最大;当激光功率密度为3 GW/cm^(2),材料表面残余压应力值最高;当冲击次数达到5次以上时,材料表层的位错密度不断增大;当在工件表面覆盖一层高强度的光滑金属接触膜时,材料表面粗糙度将降低。综合数据可知激光功率密度及冲击次数对钛合金疲劳寿命的影响最大。整理了大量试验数据,可为得到最佳的激光冲击强化效果及提升疲劳寿命提供理论参考。

Laser Shock Processing and Its Effect on Fatigue Life of Titanium Alloys : A Review

In order to promote the fatigue strength of titanium alloy parts, scholars have carried out experimental research on the related technology, but the lack of systematic introduction of this technology hinders the industrial application of it. A lot of experimental data and results are collected, and the effect of laser shock peening on fatigue properties of titanium alloy parts is analyzed. The development of laser shock strengthening technology is introduced, and the surface morphology, residual stress, microstructure, hardness and surface roughness are analyzed and summarized respectively. The results show that when the laser pulse energy is 7 J, the plastic deformation of the material reaches the maximum. When the laser power density is 3 GW / cm² , the residual compressive stress is the highest. When the impact number reaches more than 5 times, the dislocation density of the material surface increases continuously. When the workpiece surface is covered with a high strength smooth metal contact film, the surface roughness of the material will be reduced. Comprehensive data show that laser power density and impact times have the greatest influence on fatigue life of titanium alloy. A large number of experimental data are sorted out, which provides an important theoretical reference for obtaining the best laser shock strengthening effect and improving fatigue life.