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 / cm(2), 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.