Investigation of single-stage incremental hole flanging of AA1050 through conical tool

Incremental Hole Flanging (IHF) involves the bending of hole edges around their perimeters. Multi-stage IHF strategies have demonstrated the successful formation of hole flanges. However, these strategies are time-consuming and increase the production time. To mitigate this, there is a need to minimize production time by reducing forming stages. This manuscript introduces a single-stage IHF method employing a conical tool. An analytical model is developed to determine the threshold tool angle. Optimal tool angles are investigated through Finite Element Analyses (FEA) using AA1050. The investigation underscores the viability of the proposed methodology for successfully forming hole flanges. With an increase in tool angle, larger flanges are attainable, albeit accompanied by a decrease in flange angle. Results indicate higher circumferential straining compared to meridional straining, with failure primarily occurring at the flange edge. The process mechanics are similar to the typical hole expansion process, distinguishing it from conventional ISF processes.