Improved ductility of magnesium alloy sheets by pre-hardening and annealing

The mechanical behaviour of AZ31 magnesium alloy sheets were evaluated at different directions tilting 0, 45 and 90° to rolling direction. A suitable critical point of pre-stretching has been investigated through the work hardening curve of the magnesium alloy sheets. The microstructure and mechanical properties were examined and compared. The results indicated that the average yield strength of the 0, 45 and 90° pre-hardened 4% specimens followed by annealing decreased 30 MPa and the average uniform elongation increased up to 38% compared with the as received sheet. Pre-hardening process is suggested as a potential technique to improve the ductility and anisotropy of magnesium alloy sheets.