Microstructure and corrosion resistance of a Mg₂Sn-dispersed Mg alloy subjected to pulsed electron beam treatment

We report that the corrosion resistance of a Mg–Sn-based alloy with Mg₂Sn precipitates can be considerably improved by surface modification using pulsed electron beam treatment. The alloy subjected to a pulse electron beam treatment showed a modified surface layer with a thickness of ∼12 µm, appearing more resistant to corrosion attack than the bare surface of the alloy. In 0.6 M NaCl solution, the alloys with and without the surface modification exhibited average corrosion rates of 4.3 and 8.1 mm y ⁻¹, respectively. The improved corrosion resistance was attributed to reduced cathodic activation, resulting from the surficial reduction of relatively noble Mg₂Sn precipitates.