PNNL

Abstract

In this study, we investigated the effects of laser surface treatment (LST) on the corrosion resistance of lightweight metal alloys, specifically AA6061 and AZ31. LST was performed underwater, using a nanosecond pulse laser and without using a protective coating or layer on the workpiece. The corrosion behaviors of these alloys were analyzed through electrochemical tests, including open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP) measurements. The results demonstrated that LST significantly improved the polarization resistance, and higher laser power intensities led to increased corrosion resistance and reduced corrosion rates. This enhancement in anti-corrosion performance is attributed to the formation of a protective oxide layer on the surface, acting as a barrier against corrosion. The findings underscore the potential of laser surface treatment as a viable technique for enhancing the corrosion resistance of lightweight metal alloys.