Numerical and Experimental Forming of a Cylindrical Cup in 7075-T6 Under Warm Temperature Conditions

Abstract

The use of aluminium alloys with high mechanical properties is very interesting to reduce the weight of parts, especially in the automotive industry. However, forming of these alloys at room temperature (RT) is difficult, especially for complex parts where fracture often occurs before the end of the forming process. The warm forming process, which consists of heating aluminum alloys to a temperature between 150 and 250 $^{\circ }$C, increases formability and thus allows complex shapes to be formed. In this study, forming of a cylindrical cup using a specific two-step drawing device by two reductions of the blank diameter is performed at RT and 200 $^{\circ }$C for a 7075-T6 alloy. These two forming steps are also numerically simulated using Abaqus. Forming at RT leads to the failure of the cup in the first stage, which is also obtained by numerical simulation with plastic deformations higher than what the material can support. At 200 $^{\circ }$C, the cylindrical cup can be formed in two steps, which results experimentally and numerically in a significant reduction of the forming forces.