Anodic coating of Mg-Nd-Gd-Zn-Zr (ev31a) and Mg-Y-Nd-Gd-Zr (WE43C) in saline solution

Mg-Nd-Gd-Zn-Zr (EV31A) and Mg-Y-Nd-Gd-Zr (WE43C) are heat-treatable magnesium (Mg) alloys which are used in aerospace and high-performance applications. Their strength to weight ratios are higher than aluminum alloys. In addition, their corrosion resistance was improved. Anodization in NaF is a typical method to protect surface of Mg alloys from corrosion. EV31A and WE43C in as-received and peak-aged conditions were anodized in NaF and investigated. The studies were conducted in 0.1 M NaOH solution with 500 ppm of chloride concentration. Anodized EV31A in as-received condition showed similar pitting protection potential to the non-anodized one. In contrast, peak-aged EV31A which was not anodized presented better pitting protection potential compared to anodized peak-aged EV31A. Pitting protection potentials of both as-received and peak-aged conditions of WE43C were improved when the materials were anodized.