Influence of Zn addition on aging response and corrosion resistance of Mg-Gd-Nd-Zr alloy

Abstract

The age hardening response and corrosion resistance of Mg-8%Gd-2%Nd-0. 39fcZr alloys with various Zn contents up to 2% (in weight) have been investigated. The Zn-free alloy exhibits relatively lower age hardening and slower age response, whereas the addition of Zn enhances the age hardening response remarkably. The weight loss after salt spray test decreases with increasing Zn content in the peak-aged alloys, which is presumably associated with the increased amount of eutectic Mg-Zn-Nd-Gd phase acting as a corrosion barrier along the α grain boundaries. The potentiodynamic polarization curves reveal that with the increase in Zn content, the value of I corr decreases gradually while the value of Ecorr increases. © 2008 The Japan Institute of Metals.