Process model and experimental analysis of circumferential extending extrusion forming for magnesium alloy sheet

In order to further enrich the existing manufacturing methods and approaches of magnesium alloy sheet forming, a new process of circumferential extending extrusion forming of magnesium alloy sheet, which focuses on the process principle and characteristics of the method, is proposed in this paper. Through theoretical analysis, technological theoretical models such as the dimension relationship between the original billet and the formed sheet and the extrusion speed were deduced. The circumferential extending extrusion process of AZ31 magnesium alloy sheets was experimented. The results show that the backpressure ring of pure aluminum can change the stress state of the sheet during extending extrusion and effectively restrain the change of sheet thinning trend and cracking defects at the outer edge caused by tensile stress, and the product quality is improved remarkably. According to the actual requirements, the size of the required sheets can be customized. It can be seen from the comparison that as the distance from the axis increases, the average grain size of the product decreases remarkably, and and the degree of recrystallization is higher. Meanwhile, the microstructure is refined. With the maturity of the process, it is expected to provide a new idea for the short-process forming of high-performance lightweight alloy sheets.