多晶铜轴对称变形织构的纵向塑性各向异性

Applying Taylor-Like Model Successfully to Describing Longitudinal Plastic Anisotropy of Axisymmetric Deformation Texture for Polycrystalline Copper

应用Taylor类多晶体塑性模型对轴对称变形下多晶铜的变形织构进行了数值模拟,分析了变形过程中多晶铜屈服应力的各向异性演化情况;计算分2步:先对随机分布多晶集合体进行轴对称拉伸,然后分别沿已变形的多晶集合体的各方向再进行拉伸变形,得到了屈服应力的取向分布及纵向塑性各向异性的直观图像,为变形织构塑性各向异性力学行为的宏观模型描述提供了一个数值实验。

It is well-known that, when polycrystalline bodies develop plastic deformation, grains of sheet metal produce plastic anisotropy through their preferential orientation. In this paper, we apply the Taylorlike polycrystalline model established by Asaro and Needleman in Ref. 2 to investigating the evolution of the anisotropic behavior of face centered cubic （FCC） polycrystalline copper with {111} 〈110〉 slip systems. First, we stretch the polycrystalline copper with random distribution in the axisymmetrical direction, and then stretch it in all directions after it undergoes axisymmetrical deformation. The investigation produces the portraits of longitudinal plastic anisotropy of its axisymmetrical deformation textures, shown in Fig. 3 in the full paper. We also use the Taylor-like polycrystalline model to analyze the longitudinal plastic anisotropy. The analysis results, summarized in Fig. 4 showing the contours of longitudinal flow stress in several typical planes, indicate preliminarily that, as the equivalent stress increases, the longitudinal plastic anisotropy becomes obvious. When the equivalent stress equals to 1.0, the plastic anisotropy of axisymmetrical deformation is stable. The paper has provided successfully the results of a numerical experiment for describing the plastic anisotropy of deformation texture using a macro model.