Effect of Zn addition on the stress corrosion cracking of as-cast BCC Mg-11Li based alloys

The stress corrosion cracking (SCC) of ultralight Mg-11Li alloys with different Zn content revealed the obvious SCC sensitivity of mechanical ductility, while the mechanical strength is minimal. The less Zn (1 wt. %) addition can improve SCC resistance, while none (1 wt. %) or massive Zn (3, 6 wt. %) addition presents the opposite effect. The lowest SCC sensitivity of Mg-11Li alloy with 1 wt. % Zn is determined by the excellent surface film and insignificant micro-galvanic effect, while elevating Zn will enhance SCC sensitivity due to the considerable micro-galvanic effect induced by cathodic second phase and anodic β-Li matrix.