Microstructure and mechanical properties of stainless steel under Nd:YAG pulsed laser irradiation

Microstructure and mechanical properties of stainless steel under the Nd:YAG pulsed laser irradiation were investigated. X-ray diffraction was used to identify the phases in the laser treated layer, and the growth morphology was observed by field emission scanning electron microscope. The results showed that a homogeneous microstructure with fine grains (60-300 nm) can be attained under the applied laser energy densities (2.175 x 10(3) to 3.585 x 10(3) J cm(-2)) and after that, it was difficult to get further refinement. Mechanical properties including microhardness and sliding wear were evaluated. The results indicated that the laser surface treatment was beneficial to increase the microhardness and to decrease the sliding wear rate.