Microstructures and mechanical properties of Mg–Al–Zn–Ca alloys fabricated by high frequency electromagnetic casting method

The microstructures and mechanical properties of AZ31 and 1 wt%Ca-containing AZ31 billets fabricated using EMC (Electromagnetic Casting) and EMS (Electromagnetic Stirring) were examined. The results show a great potential of producing high-quality surface magnesium billets with fine-grained microstructure at a relatively high casting speed. Application of EMC + EMS for production of the 1 wt%Ca-AZ31 alloy billet with a diameter of 150 mm produced a reasonably homogeneous microstructure composed of fine grains with an average size of 45 μm. Attainment of the fine-grained and homogeneous microstructure by EMC + EMS was attributed to reduction of temperature gradient and fragmentation of dendrite structure under electromagnetic force. Strength of the EMC and EMC + EMS 1 wt%Ca-AZ31 billets was higher than that of the EMC AZ31 billet due to the grain size and particle strengthening effects.