Virtual Orthogonal Optimization in Upsetting of Cone End Billet with Large Height-To-Diameter Ratio

Abstract

To restrain bulging in the upsetting of the larger height-diameter ratio (LHDR) billet, a novel upsetting method named cone end billet upsetting (CEBU) is proposed in this article. This method is featured by prefabricating cone shape at billet ends, and aimed to obtain a smaller rigid deformation zone in forming. The forming characters of a cylinder LHDR billet were analyzed by the commercial finite element software DEFORM. Moreover, virtual orthogonal tests were proceeded to uncover several influence factors such as billet end taper, pressing speed and billet height. The results show that bulging can be effectively restrained in CEBU. In the condition of billet end taper α = 15°, pressing speed υ = 0.5 mm/s, and billet height h = 35 mm, a much smaller bulging can be achieved. The simulated results are in good agreement with experiment which was conducted with polycarbonate samples, and indicate CEBU is a promising method to control bulging in the upsetting of LHDR billet.