Tensile Properties of Directionally Solidified AZ91 Mg Alloy

AZ91 Mg alloy consisting of elongated grains was processed by a directional solidification method and mechanical properties of the directionally solidified Mg alloy were compared with those of the non-directionally solidified Mg alloy by tensile tests at room temperature and at 473 K. The directionally solidified Mg alloy exhibited higher strength at 473 K than the non-directionally solidified Mg alloy because grain boundary sliding was suppressed. Also, the directionally solidified alloy exhibited higher strength and larger elongation at room temperature than the non-directionally solidified alloy. Suppression of intergranular fracture was responsible for high ductility for the directionally solidified alloy.