Remarkably slow corrosion rate of high-purity Mg microalloyed with 0.05wt% Sc

We report that the corrosion resistance of Mg is significantly improved by adding 0.05wt% Sc. Corrosion rates evaluated from weight loss values after room-temperature immersion in 0.6 M NaCl solution for two weeks were 0.27 and 4.0 mm y−1 for the high-purity Mg samples with and without microalloyed 0.05wt% Sc, respectively. The beneficial effect of Sc microalloying on the corrosion resistance of Mg is discussed in connection with Sc-induced microstructural modifications.