Laser shock processing and its effects on microstructure and properties of metal alloys: a review

The current status of research and development on laser shock processing of metals, also known as laser peening, using Q-switched high power lasers is reviewed. The influence of processing parameters on the laser-induced shock waves in metal components are discussed and analyzed. Special attention is paid to the residual stresses and improved fatigue performance from laser peening, which are compared with conventional shot peening results. Modification of microstructure, surface morphology, hardness, and strength by laser peening is also discussed. Finally, applications of laser peening are addressed. Results to date indicate that laser peening has great potential as a means of improving the mechanical performance of components.