Experimental Study of Springback in Draw Bend Test of AZ31B Magnesium Alloy Sheet

Springback has been measured under various process conditions corresponding to those found in real press-stamping operations. The draw bend tests originally developed at Ohio State University (Carden et al., 2002 [1]) were conducted using a range of tool radii, direct controlled constraining forces, and friction conditions. Especially, the draw-bend test was able to apply precise constant restraining force and almost negligible friction by rotating the cylindrical tool with the same speed of drawn sheet strip. Springback angle changes were measured for the bending and sidewall curl regions to find the dependence on the process variables. As expected, tensile restraining force dominates the springback sensitivity, with higher forces reducing springback. The measured springback angles and curvatures were reported for use in modeling of springback of higly anisotropic and asymmetric magnesium alloy sheets.