Effect of edge-preforming route on pre-strain development and wrinkle suppression during a subsequent spinning pass

Wrinkling remains a limiting defect in spinning processes because the unsupported rim is subjected to repeated circumferential compression, local bending, unloading, and partial recovery during roller contact. This study examines how the edge-preforming route affects pre-strain development, local strengthening, and pass-level wrinkle suppression during a subsequent spinning pass of AA5052-O blanks. Two edge-preforming routes are compared, namely edge forming by bending and edge forming by spinning. Although both routes produce a flanged edge, they impose different deformation histories near the flange root and curvature band. Controlled spinning experiments, Vickers microhardness mapping, and pass-resolved finite element analysis were combined to relate the inherited curvature-band condition to the subsequent wrinkling response. The results show that edge forming by spinning produces a broader prestrained region and a higher level of retained local strengthening than edge forming by bending. This inherited condition improves rim stability during the investigated pass by promoting a more recoverable hoop-strain response and reducing the severity of final circumferential waviness. Edge forming by bending gives an intermediate response, while the flat blank reaches the critical wrinkling condition earlier. The inclined-gap schedule delays late-stage instability for cases close to the wrinkling limit, but it does not change the route-dependent stability order established by edge preforming. The experimental results are therefore evidence of improved pass-level wrinkle suppression, not proof of complete multi-pass conventional-spinning formability. Further validation is required to assess inward material flow, diameter reduction, wall-thickness evolution, residual stress development, and final part accuracy over a complete forming route.