基于晶体塑性有限元模型的异步轧制纯铜箔变形行为晶粒统计效应（英文）

发布时间：2018-03-31 21:53

本文选题：极薄带轧制　切入点：晶粒各向异性　出处：《Transactions of Nonferrous Metals Society of China》2015年10期

【摘要】：采用一种真实的多晶集合体模型和晶体塑性有限元模型,研究异步轧制纯铜箔塑性变形晶粒统计效应。考虑局部硬化耗散作用,根据取向分布函数在取向空间中的分布规律将晶体取向分配给各个晶粒的单元积分点,建立弹塑性大变形条件下的相关多晶体塑性模型,并将其引入隐式有限元法。对非均匀材料流动、铜箔厚度一定时接触压力和轧制力随晶粒尺寸增加而降低的变形行为进行研究。结果表明,在箔材厚度方向上只有少数几个晶粒时,晶粒尺寸、形貌和取向不再均匀分布于箔材中,材料的变形行为主要受到单个晶粒变形行为的影响,从而导致非均匀变形及模拟和实验结果更加离散。研究变形过程中滑移系的启动过程,晶粒取向对滑移系的启动和滑移带的形成具有重要影响,预测结果与表面层模型一致。随着晶粒尺寸的增加,表层晶粒效应增大,更加有利于降低轧制力和激活表层晶粒内滑移系的开动。通过箔材轧制实验和模拟,可以更加深入地理解异步轧制极薄带微塑性变形的机理。
[Abstract]:A real polycrystalline aggregate model and a crystal plastic finite element model are used to study the grain statistical effect of asynchronous rolling pure copper foil in plastic deformation.Considering the local hardening dissipation, according to the distribution law of orientation distribution function in the orientation space, the crystal orientation is assigned to the unit integral points of each grain, and the relative polycrystalline plastic model under the condition of large elastic-plastic deformation is established.It is introduced into the implicit finite element method.The deformation behavior of the inhomogeneous material flow and the contact pressure and rolling force decrease with the increase of grain size when the thickness of copper foil is constant.The results show that when there are only a few grains in the thickness direction of the foil, the grain size, morphology and orientation are no longer uniformly distributed in the foil, and the deformation behavior of the material is mainly affected by the deformation behavior of a single grain.As a result, the non-uniform deformation and the results of simulation and experiment are more discrete.The starting process of the slip system during deformation is studied. The grain orientation has an important effect on the initiation of the slip system and the formation of the slip band. The predicted results are consistent with the surface layer model.With the increase of grain size, the effect of surface grain increases, which is more favorable to reduce rolling force and activate slip system in surface grain.Through the experiment and simulation of foil rolling, the mechanism of micro-plastic deformation of asynchronous rolling strip can be further understood.
【作者单位】：东北大学轧制技术及连轧自动化国家重点实验室;东北大学材料与冶金学院;
【基金】：Project(51374069)supported by the National Natural Science Foundation of China Project(U1460107)supported by the Joint Fund of the National Natural Science Foundation of China
【分类号】：TG339

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