Dislocation substructures of three die-cast Mg-Al-Ca-based alloys

Dislocation substructures of three crept Mg-Al-Ca-based alloys have been characterized using transmission electron microscopy. At low temperature, most dislocations are basal 〈a〉 type, while at higher temperatures, basal and non-basal 〈a〉 dislocations are observed with isolated 〈c〉 or 〈c + a〉 dislocations. Although creep resistance varies substantially, no major differences in crept dislocation substructures are observed. Differences in creep behavior are not attributable to different creep mechanisms and may be due to strengthening of primary alpha phase instead.