Microstructures and mechanical properties of extruded and heat treated Mg-6Zn-1Si-0.5Mn alloys

► The extruded Mg-6.Zn-1Si-0.5Mn(-Ca) had a yield strength of ∼200 MPa. ► The duplex aging increased the yield strength to 340 MPa. ► The addition of Ca to this alloy enhanced the work hardening and refined grain size. ► Ca additions did not affect the precipitation hardening. ► The strengthening due to [0 0 0 1] rods of MgZn2.