电磁力径向助推筒形件渐进复合拉深变形基础研究

This project proposed a new forming method named cylindrical cup incremental composite deep drawing with radial magnetic force pushing, which combines the traditional stamping, electromagnetic forming and reconnection electromagnetic propulsion. The experimental, numerical simulation and microanalysis are combined to research the deformation mechanism of the composite deep drawing with radial magnetic force pushing. The effect of the coil structure and discharge parameters on magnetic force distribution is analyzed. The effect of technological parameters on sheet thickness, the distribution of stress and strain are revealed. The effect of sheet deformation behavior, such as bend-straighten, high velocity impact between the sheet and the die, on plasticity unsteadiness phenomenon and microstructure evolution are discussed. The forming limit diagram is established. In order to obtain the effect of technological parameters on formability, the mechanical property and service performance are measurement. Finally, a new method and theory for the cylindrical cup incremental composite deep drawing with radial magnetic force pushing are formed. It will provide an important means to manufacture aluminum alloy parts with large ratio of height to diameter, which can be used in the fields of aviation and spaceflight, et al.

本项目将传统凸模冲压、电磁脉冲成形和重接式电磁推力技术结合在一起实施渐进成形，提出一种电磁力径向助推筒形件渐进复合拉深方法。采用多物理场耦合数值模拟、工艺实验和微观分析相结合的方法研究电磁力径向助推渐进复合拉深成形方法的变形机理。研究线圈结构和放电参数对助拉磁场力和助推磁场力分布的调控理论，揭示工艺参数对板料壁厚和应力应变分布的影响规律，探讨板料弯曲-拉直、板料与模具高速碰撞等变形方式对材料的宏观失稳行为和微观组织演变的影响规律。构建材料的成形极限图。对成形后的零件的机械性能及服役性能进行测试，获取工艺参数对制件性能的影响规律。最终形成一种新颖的电磁力径向助推筒形件渐进复合拉深成形方法和理论。为航空、航天等行业中大高径比铝合金零件的精确制造技术的突破提供一种重要手段。

用传统方法很难提高铝合金零件的拉深高度，本课题提出一种电磁力径向助推筒形件渐进复合拉深方法。在线圈放电过程中，板料法兰部位材料在径向电磁力作用下向凹模内流动。与传统冲压相比，径向侧推电磁力和反向胀形电磁力配合，板料的拉深高度比准静态提高了31%；径向侧推电磁力和正向胀形电磁力配合，板料的拉深高度比准静态提高了121%。并将项目提出的方法应用于大型薄壁曲面件的拉深成形，突破了大型零件成形需要巨型装备的瓶颈。建立了“准静态+电磁渐进成形”的复合成形有限元分析模型，找到了最佳线圈结构、放电参数和磁场力载荷路径的优化匹配关系；揭示了复合拉深过程中，板料的塑性变形机制和回弹抑制理论。测试了零件成形后的力学和机械性能，分析了复合成形方式下材料的微观组织演变规律。最终形成一种新颖的电磁力径向助推筒形件渐进复合拉深成形方法和理论。