Workability of Aluminum Alloy 7075-T6 in Upsetting and Rolling

Abstract

The workability of aluminum alloy 7075-T6 was investigated in upsetting and rolling at room temperature with reference to occurrence of free-surface cracks. The fracture criterion was established by a plane-strain sheet tension test and an upset test. An improved version of the matrix method was used to obtain the complete solution in upsetting. Then a workability chart was constructed by combining the fracture criterion and the complete solution for various friction conditions and several specimen dimensions. In rolling, a theory for the analysis of spread was utilized to compute the strain history at a point on the free edge surface. With this theory it was possible to predict workability in multipass rolling with reference to edge cracking. The limiting reductions in thickness were given as functions of workpiece dimensions for various friction values. Experimental results demonstrated that the predictions were very good.