Influence of the deformation temperature on the formability of AA5083 during electromagnetic forming

Electromagnetic forming (EMF) is a promising and rapidly developing high-speed forming technique of lightweight materials. However, there is currently a lack of accurate analysis of the thermal effect of eddy current induced in workpieces and the influence of deformation temperature on formability. In this work, a multi-sized workpiece method was proposed for electromagnetic ring expansion tests, and a one-dimensional uniaxial high-speed tensile test of 5083 aluminum alloy (AA5083) rings with varying temperatures and the same strain rate was conducted to analyze the influence of thermal effect on deformation behavior. It was found that the fracture strain first increased and then decreased with increasing temperature, and the maximum fracture strain reached 30.8%. It can be concluded that the optimal deformation temperature range of AA5083 in EMF was 171-211 degrees C. The deformation texture and microstructure evolution were investigated using electron back-scattered diffraction. The results indicated that the temperature within the optimal deformation temperature range promoted the occurrence of dynamic recovery, which was the main reason for the enhanced ductility of AA5083 in EMF. The process was gradually replaced by dynamic recrystallization as the temperature increased, which decreased the ductility. Determination of optimal deformation temperature in EMF can further improve the formability of AA5083, and studying the thermal effect caused by eddy current is instructive for the development and application of EMF.