镁合金电流辅助电磁胀形特性实验研究

Experimental Study on Current Assisted Electromagnetic Forming Characteristics on Magnesium Alloy

摘要: 镁合金室温下塑性极差，限制了镁合金塑性成形工艺的发展。本文结合电流辅助成形和电磁成形等高能率成形工艺的优点，提出一种对镁合金带孔管件孔沿成形的电流辅助电磁成形工艺方法。依据同轴同相脉冲电流作用原理设计了芯棒线圈和试验管件。对AZ31B镁合金退火薄壁管件的实验结果表明，镁合金电辅助电磁成形在镁合金电导率低的情况下，仍具有足够强的成形力，11 kV放电电压，14.2 kJ放电能量下，16 mm外径，壁厚1 mm的镂空管胀形系数达到1.94；方法对镁合金有显著的增塑增强作用，相比室温准静态工况，镁合金延伸率提升了146%，成形后硬度提升了54%；通过对断口的分析发现，脉冲电流辅助对镁合金塑性增强起重要作用。本研究为镁合金室温塑性成形工艺提供了一种新思路。

Abstract: The poor plasticity of magnesium alloys at room temperature limits the development of plastic forming processes for magnesium alloys. This article proposes a current assisted electromagnetic forming process for forming the hole edge of magnesium alloy perforated pipe fittings, combining the advantages of high-energy forming processes such as current assisted forming and electromagnetic forming. Based on the principle of coaxial in-phase pulse current, the core rod coil and test tube were designed. The experimental results of AZ31B magnesium alloy annealed thin-walled pipe fittings show that magnesium alloy electric assisted electromagnetic forming still has sufficient forming force under low electrical conductivity of magnesium alloy. At a discharge voltage of 11 kV and a discharge energy of 14.2 kJ, the bulging coefficient of a hollow tube with an outer diameter of 16 mm and a wall thickness of 1 mm reaches 1.94. The method has a significant plasticizing and strengthening effect on magnesium alloys. Compared with room temperature quasi-static working conditions, the elongation of magnesium alloys has increased by 146%, and the hardness after forming has increased by 54%. Through analysis of the fracture surface, it was found that pulse current assistance plays an important role in enhancing the plasticity of magnesium alloys. This study provides a new approach for the room temperature plastic forming process of magnesium alloys.