Hot working parameters and mechanisms in as-cast Mg–3Sn–1Ca alloy

The hot working characteristics of as-cast Mg–3Sn–1Ca alloy have been studied using processing-map technique and the kinetic rate equation. The map exhibited two domains; one in the lower strain rate range (0.0003–0.01 s − 1 ) and the other in the higher strain rate range (0.1–10 s − 1 )—both falling in the same temperature range of 350–550 s − 1 . Hot extrusion at 500 °C and a speed corresponding to an average strain rate of 3 s − 1 exhibited dynamically recrystallized microstructure. The estimated apparent activation energy values are higher than those for self-diffusion in pure magnesium suggesting that the large volume fraction of MgSnCa intermetallic particles causes significant back stress.