Three-dimensional plastic response in polycrystalline copper via near-field high-energy X-ray diffraction microscopy
Three-dimensional plastic response in polycrystalline copper via near-field high-energy X-ray diffraction microscopy
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DOI：
10.1107/s0021889812039519
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发表时间：
2012-12
影响因子：
6.1
通讯作者：
S. F. Li;J. Lind;C. Hefferan;R. Pokharel;U. Lienert;A. Rollett;R. Suter
中科院分区：
文献类型：
--
作者：
S. F. Li;J. Lind;C. Hefferan;R. Pokharel;U. Lienert;A. Rollett;R. Suter
在一个多晶样品的铜的晶体取向场的演变映射在三维拉伸应变的应用。使用先进光子源收集的高能X射线衍射显微镜数据的前向建模分析，在10.2 μm的长度尺度上以10.1 °的取向精度证明了跟踪晶内取向变化的能力。晶粒内的晶格旋转在状态之间以0.1 °的精度被跟踪。详细分析了样品的横截面前和后的106%的应变。基于体素（0.625 µm三角网格）的重建结构用于计算内核平均的取向差图，其表现出复杂的图案。来自重建取向场的模拟散射被证明可以再现由缺陷微结构产生的复杂散射图案。与优化的取向场相关联的拟合优度或置信度度量的空间变化指示相对高或低取向紊乱的区域。一个对齐程序是用来匹配样品的横截面在不同的应变状态。数据和分析方法指向多晶塑性计算模型预测和材料宏观体积的实验观察之间进行详细比较的能力。
The evolution of the crystallographic orientation field in a polycrystalline sample of copper is mapped in three dimensions as tensile strain is applied. Using forward-modeling analysis of high-energy X-ray diffraction microscopy data collected at the Advanced Photon Source, the ability to track intragranular orientation variations is demonstrated on an ∼2 µm length scale with ∼0.1° orientation precision. Lattice rotations within grains are tracked between states with ∼1° precision. Detailed analysis is presented for a sample cross section before and after ∼6% strain. The voxel-based (0.625 µm triangular mesh) reconstructed structure is used to calculate kernel-averaged misorientation maps, which exhibit complex patterns. Simulated scattering from the reconstructed orientation field is shown to reproduce complex scattering patterns generated by the defected microstructure. Spatial variation of a goodness-of-fit or confidence metric associated with the optimized orientation field indicates regions of relatively high or low orientational disorder. An alignment procedure is used to match sample cross sections in the different strain states. The data and analysis methods point toward the ability to perform detailed comparisons between polycrystal plasticity computational model predictions and experimental observations of macroscopic volumes of material.