Strength and Plasticity Synergistic Enhancement Mechanism for AZ31B Magnesium Alloy Using Electrically Assisted Electromagnetic Forming

Abstract

Few independent slip system causes poor formability of magnetic alloys at room temperature. Electromagnetic forming (EMF) is a high‐rate forming method, which improves formability of magnetic alloy. However, conventional EMF weakens energy utilization, and reduces strength and plasticity of formed parts. In this work, a novel electrical assisted electromagnetic forming (EAEMF) is proposed to improve energy utiization and properties of AZ31B alloy. nergy utilization of EAEMF is 100% higher than that of EMF under same height limit, which is due to the greater temperature and electromagnetic force acting on the sheet during EAEMF. Moreover, average tensile strength, yield strength, and elongation of the EAEMF specimen are 7.5%, 6.7%, and 50% higher than those of the EMF‐produced sample, respectively. This is because EAEMF promotes grain refinement, induces more twins and dislocations, which is beneficial for enhancing strength and plasticity. Particularly, twin density of EAEMF sample increased by 70%, grain size decreased by 26.6% owing to dynamic recrystallization. In addition, EAEMF weakened basal texture, increased deformation region and more uniform plastic deformation, provided more interfaces to accommodate disocations, which ensured the increase of plasticity. Therefore, this study proves the feasibility and superiority of EAEMF, providing new prospect for improving property of magnesium alloy parts.