Effect of nanosecond laser modification on roughness, morphological and wettability state of Ti Grade 2 surfaces

Abstract In this study, the impact of laser structuring parameters on the surface roughness and wettability of flat Ti Grade 2 surfaces was examined. Six experimental surfaces were prepared applying different levels of laser pulse energy maintaining the constant value of the scanning speed and five surfaces were prepared using various values of scanning speed while keeping the pulse energy constant. The surface morphology was documented employing high-resolution digital microscopy followed by the surface roughness parameters measurement using the contact profilometer. Finally, the surface wettability was measured using the sessile drop technique. The contact angle values in the range of 68.64° to 95.92° were detected, showing the tendency of increasing with the increase of the scanning speed. It corresponds with the trend of surface roughness parameters Rsk and Rkμ to be higher when the scanning speed is increased. The growth of the laser pulse energy revealed the contact angles from 47.29° to 112.39°, with an opposite tendency of the contact angle decreasing with the rise of the laser pulse energy. It is consistent with the trend of a slight decrease in the surface profile kurtosis Rkμ when the pulse energy grows.