Electromagnetic driven forming utilizing a metal ring for controlling shapes of sheet metals

Electromagnetic forming (EMF) has unique advantages in processing metallic materials owing to the high-strain effect. However, it possesses poor shape-control ability for workpieces and is not suitable for forming materials with low conductivity. To address this, an electromagnetic-driven forming method with a metal driven ring is proposed to achieve Lorentz force transforming and shape control of the workpiece. The effectiveness of this method and ring configurations on the deformation behavior of AA1060-H24 aluminum alloy sheets, along with the forming mechanism, have been thoroughly investigated in combination with experiments and simulations. Results demonstrate that the introduction of the driven ring can adjust the Lorentz force generated on the sheet, resulting in a flat-topped profile with a uniform deformation ratio of 0.62, which increases by 100% compared to that without a driven ring. Meanwhile, it is discovered that the uniform deformed area, forming shapes, and targeted deformation areas can be controlled by regulating the ring configurations, which indicates that the proposed method possesses good adaptability and flexibility in shape control. Moreover, it has also been validated and applied in forming low-conductivity titanium sheets, which can be deformed into a flat-topped shape. This work provides an effective approach for shape control by aggregating the Lorentz force on the driven ring, which is essential for broadening the scope of EMF technology within the domain of sheet metal processing.