Femtosecond and Nanosecond Laser Peening of Stainless Steel

We have compared the results of laser shock peening obtained by using a femtosecond laser with those obtained by using a nanosecond laser. Commercial SUS304 stainless steel was used as the test sample. The sample was subject to femtosecond or nanosecond laser-shock loading in a plasma confined by water. The Vickers microhardness test was used to evaluate the work hardening in the sample due to the plastic deformation induced by the laser peening. The surface hardness of stainless steel increased linearly with laser energy. The results of this study indicate that the extent of work hardening is similar for both femtosecond and nanosecond laser peening. DOI:10.2961/jlmn.2010.02.0014