【作者】 谢玲玲；

【导师】 宋宝韫；

【作者基本信息】 大连交通大学 ， 材料加工工程， 2005， 硕士

【摘要】 连续挤压扩展成形工艺具有扩展比大、生产率高、节能效果强、质量好、成材率高等优点,特别适于大尺寸、高强度和有特殊要求长度的产品的生产。采用此工艺研制铜母线与传统生产工艺相比极具优越性。 连续挤压生产铜母线的过程非常复杂,材料性能、模具形状、工艺参数、温度等对成形过程都有影响。若工艺参数和模具结构尺寸选择不当,易造成产品的弯曲、裂纹、缺料等缺陷,模具也极易损坏。为此,本课题力图通过数值模拟分析金属的流动规律,由此预测挤压过程可能出现的缺陷,及时调整工艺参数,修改工艺设计,进一步提出改进方案。 本文采用DEFORM软件作为模拟分析的工具,基于刚塑性/刚粘塑性有限元理论,建立了成形过程的有限元模型。论文共分为五大部分: 1.结合连续挤压技术与扩展成形工艺特点,阐述了利用有限元模拟来分析铜母线连续挤压扩展成形过程的必要性、可行性及优越性。 2.根据铜母线的塑性变形特点,对复杂成形过程的数值模拟选用刚塑性/刚粘塑性有限元法,为其建立合理的理论模型,选择适宜的求解方法,力求接近模拟真实。 3.对连续挤压过程进行了力能综合分析,推导了连续挤压变形力的计算公式,确定了工作状态下主机系统所需的扭矩大小。 4.为求得与实际过程相符的模拟结果,研究了有限元模拟的关键技术,有助于不断发展和完善模拟系统。 5.对成形过程的数值模拟结果进行了详细的分析,得到了金属流动的速度场、温度场、等效应力场、等效应变场和扭矩一行程曲线等,揭示了金属的流动变形规律,并用模拟结果来指导和优化工模具设计,改善连续挤压扩展成形过程。 总之,根据模拟结果分析,可合理选择工艺参数和模具结构尺寸,实现铜母线连续挤压扩展成形,力求把连续挤压的生产率和能量节省提高到更先进的水平。更多还原

【Abstract】 Continuous extrusion extending forming technics has much excellence as big extending scale, high productivity, strong energy-saving, ascendant quality and good molding ratio and so on, especially adapts to the products with big dimension, high intensity and extra requirement of length. By comparision with using traditional technics, the copper generatrix produced by introducing this technics possesses enough advantage.The process of producing the copper generatrix by using continuous extrusion technics is very complicated, and the material capability, mould figure, technics parameters and temperature etc all affect the figuration process. If the technics parametrers and structure size of moulds are selected inadequately, a lot of disfigurement on curling, cracking and lacking material of the products will appear frequently, and the moulds will be spoiled easily. Therefore, this paper strives to analyze the moving rule of metal through numerical simulation, which can forecast the disfigurement existing in the extrusion process. So we can adjust technics parameters, amend the technics designment in time, and put forward to amelioration projects deeply.In this dissertation, we use DEFORM software as the tool to simulate and analyze, and establish the finite element analysis model of deformation process, which is based on rigid plastic/rigid viscoplastic FEM theory. This paper is made of five parts:1. Combining continuous extrusion technology with extending figuration technies characteristic, expatiate the necessity, feasibility and superiority of using FEM simulation to analyze and conpute the copper generatrix continuous extrusion extending efoumation process.2. According to plastic distortion characteristic of the copper generatrix, the rigid plastic/rigid viscoplastic FEM theory is used to simulate the complicated deformation process, and builds logical theory model, selects feasible evaluttion method, which tries hard to approach the simulation truth.3. Analyze the relation between strength and energy of continuous extrusion process. Deduce the calculate formula of deformation force, ascertain the value of machine torque when steady working.4. In order to get the simulation result matching with the real process, the key technique of the FEM simulation is researched to administer to constantly developand perfect the simulation system.5. The numerical simulation results of deformation process is analyzed detailedly, and velocity distribution, temperature distribution, effective stress and strain distribution and load-time of the metal deformation are received, which opended out the flowing distortion rule of metal. Furthermore, the mould designing was directed and optimized with the simulation results, while improving the figuration process of continuous extrusion.In conclusion, according to analyzing the simulation result, the technics parameters and die structure size should be selected reasonably, which can realize the copper generatrix continuous extrusion extending forming, and try our best to advance the productivity and save energy to a higher level.更多还原