Effect of microalloying with boron on the microstructure and mechanical properties of Mg–Zn–Y–Mn alloy

• The effect of a trace amount of boron (B) on the formation of long-periodic stacking ordered (LPSO) phase was investigated.
• Adding small amounts of B to the Mg–Zn–Y–Mn alloy can highly increase the volume fraction of LPSO phase.
• The as-cast Mg–Zn–Y–Mn–B alloy has high strength (UTS=252.5 MPa) and good ductility (elongation=11.0%) in low Y/Zn ratio.

The addition of boron to long-periodic stacking ordered (LPSO) phase-strengthened Mg–Zn–Y system alloys has been studied for the first time. The as-cast Mg94Zn2.5Y2.5Mn1 alloy containing 0.003 wt% B with abundant LPSO phase and refined grains exhibited optimal mechanical performance with ultimate tensile strength and elongation of 252.5 MPa and 11.0%, respectively.