铜箔轧制滑移系演化的晶体塑性有限元模拟

为了定量描述厚度尺寸对极薄带轧制微观变形不均匀性的影响,采用率相关晶体塑性理论和Voronoi图的多晶模型,考虑试样尺寸,晶体取向及其分布,模拟了不同厚度铜箔在相同压下率条件下的变形行为,得到了在细观尺度上铜箔的微观应力应变和滑移系分布.模拟获得的应力-应变曲线和实验测得的曲线基本一致.通过对20%压下率不同厚度铜箔的轧制变形的研究表明,无论是在晶粒内部还是在晶粒间,材料变形都非常不均匀,主要是由在铜箔厚度方向上只有一层晶粒时,晶粒尺寸、形貌和取向的不均匀分布,近邻晶粒取向差以及滑移系启动特性所引起的.

Crystal Plasticity Finite Element Simulation of Slip System Evolution in Pure Copper Foil Rolling

The distributions of the stress， strain and slip systems in pure copper foil rolling with the same reduction were simulated by the rate-dependent crystal plasticity theory and Voronoi polycrystalline model with respect to specimen dimension， grain orientation and its distribution to quantitatively evaluate the influence of thickness on inhomogeneous deformation behavior of foil rolling at mesoscale. The simulated stress-strain curves agree well with the experimental results. The simulation results reveal that the deformation behavior in the polycrystalline aggregate is inhomogeneous not only in intracrystalline but also in intergranule with a 20% reduction in foil rolling. The foils are composed of only a single layer grain across thickness， the grains with different sizes， shapes and orientations are unevenly distributed in the foil， the misorientation of neighboring grains and the property of active slip systems.