Effect of Y addition on the microstructures and mechanical properties of as-aged Mg-6Zn-1Mn-4Sn (wt%) alloy

• The as-aged Mg-6Zn-1Mn-4Sn-xY (x = 0.1, 0.5, 1.0, wt.%) alloys consist of α-Mg, Mn, MgZn2, Mg2Sn and MgSnY phases.
• Due to the high number density of rod-like β1′ phase, the as-aged Mg-6Zn-1Mn-4Sn-0.5Y alloy shows excellent mechanical properties.

The effect of 0–1.0 wt% Y addition on the microstructures and mechanical properties of as-aged Mg-6Zn-1Mn-4Sn alloy was investigated. The results showed that α-Mg, α-Mn, MgZn2, Mg2Sn and MgSnY phases were found in the as-aged Y-containing alloys. The MgSnY was a high temperature phase and could promote the age-hardening response. The as-aged ZMT614-0.5Y alloy exhibited excellent mechanical properties was attributed to the high number density of β1′ rods. Its yield strength (YS), ultimate tensile strength (UTS), elongation was 371 MPa, 376 MPa and 7.7%, respectively.