Despite possessing excellent specific properties, rapid corrosion of magnesium is a significant barrier in its widespread use. Alloying Mg to enhance mechanical properties nominally increases susceptibility to corrosion from microstructural heterogeneity. Furthermore, alloying Mg nominally accelerates cathodic kinetics and hence also accelerates corrosion. To date, no alloying additions to Mg suggest that a reduction in corrosion rate can be imparted, however we reveal for the first time that alloying additions of arsenic can impart significant corrosion resistance to Mg via retarding the cathodic reaction.
- Cathodic poison