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为了定量描述晶粒取向和结构对极薄带轧制微观塑性变形非均匀性的影响,采用晶体塑性有限元方法(CPFEM)和Voronoi图的多晶模型,考虑试样尺寸、晶粒尺寸、晶体取向及其分布,模拟了不同厚度Cu极薄带在相同压下率条件下的滑移与变形行为,得到了介观尺度上Cu极薄带的微观应力-应变和启动滑移系分布.模拟获得的应力-应变曲线和实验测得的曲线基本一致,验证了晶体塑性有限元模型的准确性.通过对40%压下率Cu极薄带轧制变形的研究表明,无论是在晶粒内部还是在晶粒间,材料内部的变形都非常不均匀,这种不均匀性主要是由初始晶粒取向和结构不同、近邻晶粒取向差以及变形时滑移系的运动特性和晶粒旋转不同引起的.滑移系首先在自由表面和晶界处被激活,而后引起晶粒内部滑移系的启动与运动.
In order to quantitatively describe the influence of grain orientation and structure on the microscopic plastic deformation non-uniformity in ultra-thin strip rolling, the crystallographic finite element method (CPFEM) and the Voronoi diagram of the polycrystalline model were used to consider the sample size, grain size, Orientation and distribution of Cu thin films were simulated to simulate the sliding and deformation behaviors of Cu thin strips with different thickness under the same reduction rate and the microstress-strain and start-slip distributions of Cu thin strips at mesoscopic scale were obtained. The obtained stress-strain curve is basically the same as the experimentally measured curve, which verifies the accuracy of the plasticity finite element model.According to the research on the rolling deformation of Cu thin strip with 40% reduction rate, Or within the grains, the deformation of the material is very inhomogeneous. The inhomogeneity is mainly caused by the difference of the initial grain orientation and the structure, the difference of the grain orientation of the adjacent grains, and the movement characteristics of the slip system and the rotation of the grain when deformed The slip system is first activated at the free surface and at the grain boundaries and then starts the movement and the slip of the interior grain.