Prediction of earing in drawn cup based on crystallographic texture data of sheet metal

Abstract

The plastic anisotropy of sheet metal is usually caused by preferred orientation of grains, which are developed by mechanical deformation and thermal treatment. Since the crystallographic texture of sheet metals is related to formability, especially earing, the prediction of earing with texture data is very important for the control of anisotropy of sheet metals in blank pre-processsing. In this paper, a method of earing prediction with texture data is proposed based on crystalline plasticity theory. The values of Taylor factor M on different strain paths are calculated for sheet metal with FCC crystallographic texture based on TBH (Taylor-Bishop-Hill) theory. Then the full yield surface and the curve of plastic strain ratio R versus loading direction, and the earing profile are determined for LY16 aluminium alloy sheet metal which has mixed crystallographic texture. The predicted ears are at 0°, 90°, 180° and 270°, which is in good agreement with experimental result.