Forming Limit and Mechanical Properties of 2024-O Aluminum Alloy Under Electromagnetic Forming

The effect of electromagnetic forming (EMF) on the forming limit and properties of 2024-O aluminum alloy is studied in this paper. This was done to address the important problems related to the poor forming limit of aluminum alloy when conventional stamping is used. The evolution of the microstructure of the alloy during quasi-static stamping (QS) and the dynamic deformation is analyzed. This was done using mechanical testing, texture analysis, scanning electron microscopy (SEM), fracture analysis, and transmission electron microscopy (TEM). Compared with QS, the forming limit for EMF increases by 36.9%. For the same deformation height with 17.6mm, the maximum degree of thickness thinning of the sample for EMF is 4.7%, and 6.4% for QS. The thickness distribution of the EMF sample is more uniform than for the QS sample. Numerical simulation shows the maximum principal stresses at different points were almost same with each other after EMF, which leads to uniformity plastic deformation of samples. In addition, the grain size of the material decreases, the proportion of small-angle grains increases, and the copper texture increases after EMF. When EMF is used, the dislocation density of the sample is significantly higher than for QS and the dislocation distribution is more uniform. The temperature rise is small, which is not a significant reason for dislocation dispersed in EMF. Graphical Abstract