复杂件多向振动增量式滚轧塑性成形的基础研究

There is an urgent need to achieve the efficient, high-performance, precise forming of the shape and performance of complex workpieces such as spline shaft, etc. A new process principle is proposed to achieve incremental rolling plastic forming of complex workpieces under the coupling interaction of vibration field, temperature field and partial loading field generated by rolling die. In this project, several AC servo motors are used as the driving element to generate vibration field and partial loading field with specified frequency along the axial, tangential and radial direction of the workpiece; With the help of electromagnetic induction heating coil, the complex workpiece’s temperature field which varies in accordance with a gradient along the radial direction is obtained; The workpiece which is laid horizontally is formed under the influence of incremental partial loading field generated by no less than 3 rolling die which are uniformly distributed along the radial direction. Moreover, the constructive relation, principle of plastic deformation and microstructure evolution of common used metal materials is revealed when the complex workpiece is affected by temperature field, vibration field, partial loading field and the different mutual coupling way. The finite element model of multi-field coupling incremental rolling process of the complex workpiece is established. By this means, the numerical simulation of rolling plastic forming process under the coupling field is achieved to obtain the influence of primary parameters on the rolling forming process and the reasonable technical parameters. Furthermore, the prototype of the machine is developed for experimental proposes. Eventually, the conduct of this project will lay a solid theoretical foundation and provide support on key technics for this new process principle and its industrialization.

针对目前迫切需要解决诸如花键轴等复杂件的高效高性能精确成形成性一体化的难题，提出一种在振动场、温度场、滚轧模具产生的局部加载力场的耦合作用下，实现复杂件增量式滚轧塑性成形的新工艺原理。本课题用多个交流伺服电机作为驱动元件，沿着工件的轴向、切向、径向施加规定频率的振动场与局部加载力场；利用电磁感应加热圈，获得复杂件温度沿着径向按梯度变化的温度场；水平放置的工件在径向均布的不少于3个滚轧模具增量式局部加载力场作用下滚轧成形。揭示复杂件在振动场、温度场及局部加载力场，以及不同耦合方式作用时，常用金属材料的本构关系、塑性变形机理、微观组织的演化机制。建立复杂件的多场耦合增量式滚轧过程的有限元分析模型，实现该耦合条件下滚轧塑性变形过程的数值模拟，获得主要工艺参数对滚轧成形的影响规律与合理工艺参数，研制出相应的实验样机。为该新工艺原理及其装备的工业化应用奠定坚实的理论基础，并形成关键技术支撑。

现代制造业中汽车、机床、航天、航空等工业领域的快速发展对高性能复杂型面零部件的需求量和使用性能提出了更高的要求，而目前生产复杂型面诸如花键轴、高强螺纹轴、带有沟槽的薄壁筒体等零件广泛采用的切削工艺存在着生产效率低、机械性能差、材料利用率低等不足。因此本课题对其高效高性能精确成形、成性一体化的制造工艺及装备问题进行了系统深入的研究。. 基于材料工艺设备一体化的研究思路，本课题针对中低碳钢、合金钢、铝合金在温度、振动及其耦合作用下的塑性变形行为，揭示了塑性变形力场和温度场、振动场的耦合变形机理、微观组织演化规律。获得了成形温度、应变速率以及真实应变等工艺参数对合金钢塑性变形行为及塑性性能的影响规律，进一步揭示了塑性变形以及成形温度对促进合金钢微观组织中片状珠光体球化行为和晶粒细化的作用机制；开展了不同振动方向、不同振幅（0~0.4mm）以及不同频率（0~50Hz）下振动拉伸实验，获得不同振动参数下宏观力学性能和微观组织演变规律，揭示了塑性变形力场和振动场耦合下的材料变形机理，振动产生的周期性波动应力，提高了异号位错的接触概率，并导致位错湮灭加剧和位错密度降低，是残余软化现象的主要原因。. 针对花键轴类零件、高强螺纹轴、带有沟槽的薄壁筒体分别提出了增量式滚轧塑性成形工艺，采用理论分析、计算机建模仿真和实验研究相结合的方法，获得了主要工艺参数对花键轴齿形滚轧成形过程、滚轧力、塑性变形累积效果和流动行为的影响规律，发现耦合振动方式下滚轧力明显下降、塑性变形能力及流动的均匀性显著提高。. 研制了花键轴类零件、高强螺纹轴、带有沟槽的薄壁筒体等3台不同原理结构的分散动力伺服直驱的增量式滚轧成形样机并开展了大量实验研究工作，成功实现了对3类典型复杂型面零件高效精密滚轧成形，结果表明所提出新原理样机性能稳定、工作可靠，所滚轧的零件型面尺寸精度高、纤维组织明显，零件的抗疲劳强度和硬度显著提高。