The Effect of Die Types on Yield for Drawn Copper Sheet in a Pneumatic Forming


Pneumatic forming of nonferrous alloys is widely used to producecomponents for many traditional and advanced applications. The plastic behaviours of high purity copper sheet were investigated under pneumatic forming using open and closed dies. Experimental yield loci were determined based on the strain energy theory for open and closed dies. It has been found that the yield loci in open die expanded more than that in close die. The formability was improved due to reduction in friction coefficient. The plane strain forming and the strain distribution remain mainly uniform throughout the drawing sheet. The formed copper sheets were not thinned at the centre of the doom