Experimental study of asymmetric multi-pass spinning

Abstract

Various approaches to produce non-axisymmetric parts in metal spinning have been developed by researchers. In asymmetric multi-pass spinning, the motion of the roller is synchronized with the mandrel’s rotation by CNC codes to achieve oblique or non-circular shapes. In this study, cylindrical cups are formed using two kinds of oblique pass sets to investigate the effects of different parameters on thickness distribution and forming limit. In the translational pass set, the inclination angle is determined by the difference of the wall depths on two sides of the product and it is determined by the difference of half cone angles in the rotational pass set. The difference of wall thickness distribution in the translational pass is greater than that in the rotational pass and it increases as the inclination angle increases. The difference between the axial distributions on two sides of the wall decreases as the pass pitch increases near the top of the product, and it increases near the edge of the wall. A greater incremental angle does not affect the difference but reduces the uniformity of the wall thickness in the rotational pass set. All the failures are wrinkles in the experiments. Wrinkles occur when the pass pitch or the roller feed ratio is too large. A greater inclination angle reduces the forming limit in the translational pass set and does not affect the forming limit in the rotational pass set.