Sliding on snow of AISI 301 stainless steel surfaces treated with ultra-short laser pulses

Surface irradiation of AISI 301 with ultra-short linearly polarized pulses between 247 fs and 7 ps resulted in laser induced periodic surface structures (LIPSS). Scanning electron microscope micrographs taken after the laser treatment show the formation of sub-micrometer sized arrays of nearly parallel ripples slightly differing from each other, depending on the specific treatment adopted. Static contact angle data indicate that LIPSS induce a marked hydrophobic behavior of the treated surfaces. The friction coefficient of laser treated and pristine AISI 301 surfaces gliding on compact snow was compared to that of ultra-high molecular weight polyethylene. The friction coefficients of the laser treated samples are intermediate between those of bare AISI 301 and of UHMWPE. The changes in contact angle and surface morphology of the samples after extensive tribometer tests were tested to investigate the durability of LIPSS.