Nonisothermal Warm Deep Drawing Behavior of Automotive Grade Aluminum Alloy Sheets

Abstract

Abstract In this work, thermomechanical FE modeling of nonisothermal warm deep drawing of automotive grade AA5754 and AA6082 aluminum alloy sheets were performed. The deformable blanks were modeled using temperature dependent Cowper-Symonds constitutive equation along with Barlat-89 yield criterion. The predicted cup heights, earing, % thinning and surface strain distributions were successfully validated within acceptable error of 5%. The development of earing profile, cup thinning pattern and surface strains along 0°, 45° and 90° from rolling direction (RD) were plotted using the validated data. The ear profile developed in AA5754 cups was prominent compared to AA6082 due to relatively higher anisotropy at elevated temperatures. Thickening was more prominent along 45° to RD for AA5754, whereas thinning was higher in this direction for AA6082 material. The strain states developed at cup corner along plane strain condition was lower than the FLD0 values of materials. Thus there was uniform surface strains at cup corner indicating the improved ability of material to withstand more deformations. Comparatively, AA5754 exhibited relatively better formability compared to AA6082 material.