Martensitic transformation in temporally shaped femtosecond laser shock peening 304 steel

Laser shock peening (LSP) plays an important role in simultaneously strengthening and toughening materials for many engineering applications, such as key structures of aircraft and ship. This work focused on the application of temporally shaped femtosecond (fs) laser in shock peening 304 stainless steel. In our experiment, a single-fs laser pulse was divided by Michelson interferometer to generate two subpulses with a time delay ranging from 5...