Experimental investigation of the effect of W-temper forming process parameters on springback

Abstract

High strength aluminium alloys have drawn a lot of attention because of the expanding demand for lightweight vehicle design in the automotive sector. Due to poor formability at room temperature warm and hot forming have been advised. However, warm and hot forming methods need more steps in the production process and an advanced tooling system. In contrast, since ordinary tools can be used, forming sheets at room temperature in the W-temper condition is advantageous. However, a significant problem that must be resolved during the use of this technique is the springback of supersaturated sheets and their thinning. In this study, the high strength aluminium alloy was solution heat treated, and a U-shaped bending test was carried out at different time periods between W-temper heat treatment and forming operation. As a result, it is noted that the springback is highly dependent on the time between W-temper heat treatment and forming operations, and the change in shape increases with increasing time. The change in shape after forming was also evaluated using numerical simulation aiming to validate the experimental result. To determine the material parameters of the kinematic hardening model for numerical simulation, uniaxial tension-unload tests were performed under different ageing conditions.