Comparative study of amorphous and crystalline Zr-based alloys in response to nanosecond pulse laser ablation

In this work, we comprehensively investigate the response of amorphous and crystalline Zr-based alloys under nanosecond pulse laser ablation. The in situ multiphysics processes and ablation morphologies of the two alloy targets are explored and compared. The results indicate that the dynamics of laser-induced plasma and shock waves obey the idea blast wave theory and are insensitive to the topological structures of targets. Both targets experience significant superheating and culminate in explosive boiling. This ablation process leads to the formation of a hierarchical structure in the resultant ablation crater: microdents covered by widespread nanovoids. The amorphous target shows shallower microdents and smaller nanovoids than their crystalline counterparts because the former has a smaller heat-affected zone and experiences a higher degree of superheating. The hierarchical structure can adjust the surface wettability of targets from initial hydrophilic to hydrophobic, showing an increase of the contact angle approximately 119% for amorphous alloy compared with the crystal approximately 64%. This work demonstrates that amorphous alloys have a better performance against nanosecond pulse laser ablation and provides a feasible and one-step method of wettability modification for either amorphous or crystalline alloys