Light-weight and high strength alloys such as Al-Mg alloys are used in order to reduce the weight of industrial components. However these materials should be formed at elevated temperatures due to their poor formability at room temperature. Hot metal gas forming is one of the high-tech forming processes that is used to solve this problem. Recent investigation on tube hydroforming showed positive effect of oscillation of pressure paths in improving the formability of tubes. In this study, the effects of a sinusoidal pressure path on tube wall thinning of an Al6063 tube in HMGF processis investigated and the results are compared with equal constant pressure by the finite element method.Moreover, the effect of stroke on thickness reduction of the tube is also investigated. The results show that the proposed sinusoidal pressure paths have an obvious improvement of thinning in hot metal gas bulging of tube and some defects such as necking and bursting are prevented by the oscillation of the inner pressure. Manuscript profile

Nowadays, light weight and high strength metals are being used in various industries such as automotive and aerospace. Using aluminum-magnesium alloys is an efficient way to reduce the weight of a specific part. These alloys have poor formability in room temperature thus they should be formed at elevated temperature. Warm hydroforming and hot metal gas forming are conventional methods to form aforementioned alloys. It is proven that using hammering pressure is an efficient way in order to optimize hydroforming process that it improves formability and thickness distribution. In this paper, the effect of hammering pressure on hot free bulging of an Al6063 tube is investigated numerically and the results are compared with the results of constant pressure path. Results show that reduction of thickness is greater for peak constant pressure while using hammering pressure, due to gradual thickness reduction, could improve formability and thickness distribution. Results also show that axial feeding, increase the effect of formability caused by hammering pressure. Manuscript profile