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...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。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.展开更多
30CrMnSiA合金钢的室温成形性能差,为探究30CrMnSiA材料电流辅助成形的可行性,基于不同试验参数的电流辅助拉伸试验,研究了温度及脉冲电流参数(电流密度、脉冲占空比和频率)对30CrMnSiA流动应力的影响规律。研究表明:30CrMnSiA的强度及...30CrMnSiA合金钢的室温成形性能差,为探究30CrMnSiA材料电流辅助成形的可行性,基于不同试验参数的电流辅助拉伸试验,研究了温度及脉冲电流参数(电流密度、脉冲占空比和频率)对30CrMnSiA流动应力的影响规律。研究表明:30CrMnSiA的强度及伸长率随温度及电流密度的升高而下降,受脉冲占空比和频率影响不大;脉冲电流能抑制动态应变时效的强化作用,并促进碳化物的析出,使材料塑性下降。基于Voce模型基础,建立了考虑应变速率、温度及脉冲电流参数影响的30Cr Mn Si A电流辅助流动应力模型。利用该模型计算的结果与试验值吻合较好,说明该模型能准确预测材料在电流辅助条件下的流动应力。展开更多
文摘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。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.
文摘30CrMnSiA合金钢的室温成形性能差,为探究30CrMnSiA材料电流辅助成形的可行性,基于不同试验参数的电流辅助拉伸试验,研究了温度及脉冲电流参数(电流密度、脉冲占空比和频率)对30CrMnSiA流动应力的影响规律。研究表明:30CrMnSiA的强度及伸长率随温度及电流密度的升高而下降,受脉冲占空比和频率影响不大;脉冲电流能抑制动态应变时效的强化作用,并促进碳化物的析出,使材料塑性下降。基于Voce模型基础,建立了考虑应变速率、温度及脉冲电流参数影响的30Cr Mn Si A电流辅助流动应力模型。利用该模型计算的结果与试验值吻合较好,说明该模型能准确预测材料在电流辅助条件下的流动应力。
