Numerical study on the effect of hammering pressure on thickness reduction in hot tube metal gas forming process

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.