Influence of Sc on Microstructure and Mechanical Properties of High Zn-Containing Mg Alloy

Abstract

Microstructures and mechanical properties of Mg-11Zn and Mg-11Zn-1Sc (wt%) alloys were investigated. The main secondary phase of Mg-11Zn and Mg-11Zn-1Sc alloys is MgZn2phase. Rare earth Sc element is an effective grain refiner and the grain size of Mg-11Zn-1Sc alloy is greatly refined. The mechanical properties of the Mg-11Zn alloy were greatly improved with incorporation of 1 wt% Sc, especially for the elevated temperature strength. Such mechanical property enhancement is ascribed to the refinement and pinning mechanism of high heat-resistant Sc and Sc-containing intermetallic particles in Mg alloy.

Correlation between bonding, vacancy migration mechanisms, and creep in model binary and ternary hcp-Mg solid solutions

“…Precipitation hardening, one of the prominent strengthening mechanisms in Mg alloys, 3 has been shown to improve their creep resistance. For example, several studies 1,6,7,12,[14][15][16][17][18][19] have shown that precipitates embedded in hcp-Mg matrix of Mg-rare earth (RE) alloys retard dislocation motion and resist creep deformation, which impart high temperature strength to such alloys. Recently, it was demonstrated that a minor quantity of Zn addition to Mg-Nd-La alloys substantially increases their creep resistance by facilitating the formation of basal precipitate phases, and, to some extent, segregation of Zn atoms at defects.…”