An electromagnetic incremental forming (EMIF) strategy for large-scale parts of aluminum alloy based on dual coil

For the manufacturing of large-scale sheet parts, traditional stamping, spinning, and single-point incremental forming are limited by the rupture prone and severe springback of the formed parts and the requirement of large-scale forming equipment. In this paper, the method of electromagnetic incremental forming (EMIF) based on dual coil was creatively proposed to solve the manufacturing problem of large-scale parts of aluminum alloy. The forming results of EMIF based on single coil and EMIF based on dual coil are compared by finite element simulation. The effect of the two moving strategies on uniformity in EMIF based on dual coil was researched. In addition, the effect of the shaping voltage on uniformity in EMIF based on dual coil with the interval moving strategy was studied. It was observed that the forming quality of EMIF with dual coil was better than that of EMIF with single coil. For EMIF based on dual coil, the interval moving strategy is better than the sequential moving strategy in achieving better forming quality. For the first layer of EMIF based on dual coil with the interval moving strategy, the optimized forming voltage and shaping voltage were 12 kV and 18 kV, respectively. For the second layer of EMIF based on dual coil with interval moving strategy, the optimized forming voltage and shaping voltage were 18 kV and 27 kV, respectively. The shaping voltage was 1.5 times of forming voltage for both layers so that better forming uniformity was achieved. Then, the method of EMIF based on dual coil with interval moving strategy by multilayers is proposed to fabricate large-scale sheet parts. Finally, experiments were performed to confirm the feasibility of EMIF with dual coil, and the experiment results show good agreement with the simulation results. The findings of this work could provide guidance on deform large-scale parts of aluminum alloy by the EMIF method.