Effect of Laser Surface Structuring on Surface Wettability and Tribological Performance of Bulk Metallic Glass

Bulk metallic glasses (BMGs) have been extremely popular in recent decades, owing to their superior properties. However, how to improve the surface functions and durability of BMGs has always been a key engineering issue. In this work, a facile laser-based surface structuring technique was developed for modulation and control of the surface functionalities of Zr-based BMG. For this technique, a laser beam was first irradiated on the surface to create periodic surface structure, followed by heat treatment to control surface chemistry. Through experimental analyses, it was clearly shown that laser surface structuring turned the BMG surface superhydrophilic, and subsequent heat treatment turned the surface superhydrophobic. We confirmed that the combination of laser-induced periodic surface structure and modified surface chemistry contributed to the wettability transition. The laser-heat-treated surface also exhibited improved antifriction performance with the help of lubrication medium. This work provides a feasible method for surface modification of BMG, suggesting applications in the areas of medicine, biology and microelectronics.