Cold formability of AZ31 wrought magnesium alloy undergoing semisolid spheroidization treatment

To investigate the effect of semisolid spheroidization treatment on the cold formability of magnesium alloys, reheating experiments and cold compression tests were conducted on AZ31 wrought magnesium alloy. Fine spheroidization of the microstructure was realized when AZ31 alloy was reheated to 630 °C and held isothermally for 1800s. Semisolid treatment increased the breaking strain of AZ31 from 0.163 to 0.214 and decreased the maximum stress from 545 to 307 MPa. The cold forming mechanism of semisolid-treated AZ31 alloy was investigated quantitatively by image and mathematical analyses. The improved cold formability of semisolid-treated AZ31 alloy was mainly attributed to the slipping and shear deformation that occurred in the eutectic mixture networks surrounding the spherical grains.