Post-uniform deformation in uniaxial and equi-biaxial stretching of aluminium alloy sheets

Post-uniform deformation which affects the formability of sheet metals has been studied in the uniaxial and equi-biaxial stretching of aluminium alloy sheets. The materials used were AA5050, AA3105, and AA8014 aluminium alloys having negative, zero and positive strain-rate sensitivities, respectively. Post-uniform deformation has been characterized in terms of ‘neck breadth’ in uniaxial tension, and ‘proportional post-uniform increment in bulge height’ in biaxial tension. The results have been analyzed on the basis of the strain hardening and strain-rate hardening parameters of the materials.