Surface modification of stainless steels by TEA CO2 laser

The interaction of a transversely excited atmospheric (TEA) CO2 laser with austenitic stainless AISI 316 and high-speed tool AISI M2 steel is considered. The results have shown that both types of steel were surface modified by the laser beam, for the laser energy densities used. Morphological features on the AISI M2 were more prominent in comparison to a AISI 316 steel. On the AISI M2 steel crater like forms, solidified boundary and hydrodynamical modifications were observed, while on the AISI 316 one, corrugation, cracking and resolidified areas were registered. The morphology changes of steel surfaces in dependence of laser pulse temporal shape were analyzed especially. The pulse with a tail for difference of a tail-free pulse, for the same incident peak power density, as a rule caused higher level of damage.