Laser surface processing of ultralight magnesium alloys.
Date of Issue2012
School of Mechanical and Aerospace Engineering
Magnesium alloys have been increasingly used in the industries and biomaterial fields due to their low density, high specific strength and biodegradability. However, poor surface-related properties are major factors that limit their practical applications. Laser surface processing has been considered as an advanced technique to improve surface properties of materials. The present work investigates fundamental mechanisms of kinetics of phase transformation under non-equilibrium conditions, microstructural evolution and surface performance of laser-treated surfaces as well as laser-Mg interaction. This thesis demonstrates the capability of millisecond pulse laser in achieving the enhanced corrosion resistance and surface wettability of Mg alloy. It also analyzes heat flow and rapid solidification in the molten pool as well as material loss during laser irradiation. Furthermore, it explores theoretical study of nanosecond and femtosecond pulse laser processing on Mg alloy, and shows interesting results with potential applications.