Experimental and analytical studies for forming limit of AZ31 alloy on warm sheet metal forming

Since magnesium alloy sheet usually exhibits poor press formability, the sheet forming for complex shaped part has many difficult problems. Among these problems, the die design to prevent some defects is one of the important process variables. Therefore, the data for forming limit of AZ31 sheet is necessary to prevent the defect and get the good formed part. In this study, the forming limits on various forming process have been investigated using the experimental and FE analysis. Square cup drawing and stamping processes were used to investigate the formability of AZ31 sheet. Forming limit at elevated temperature could be predicted by FLD based on the diffuse necking. work-hardening exponent was one of the important properties to prevent the necking and improve the formability.