Improving the Forming Pressure Curves in Tube Hydroforming Process for AA1050 Alloy at Various Temperatures

Reduction of weight and increase of corrosion resistance are among the advantageous applications of Aluminium alloys in automotive industry. Low formability at room temperature is the major problem in application of these alloys. This problem is due to their microstructure (hexagonal closed pack in magnesium alloys and alloy elements in aluminium alloys) which limits the number of slip planes at the room temperature. Forming at high temperature can solve this problem. In this paper, warm hydroforming of AA1050 aluminium tubes has been studied numerically. A warm tube hydroforming were designed and fabricated. Aluminium tubes were formed at high temperatures. Simulation of process is performed using MSC. Mac commercial software and thickness distribution were studied at various temperatures. Results showed that increasing temperature improved thickness distribution. The pressure curves which were obtained using available equations for forming at room temperature, have been improved to decrease thinning in the final part. Simulations were performed in two states which are called constrained bulge and free bulge. To produce a part without any wrinkling and also to obtain minimum thinning, an axial feeding curve is suggested.

Keywords:

warm tube hydroforming , Finite element method (FEM) , Aluminium alloy