Assessing the precision of strain measurements using electron backscatter diffraction - Part 2: Experimental demonstration
Assessing the precision of strain measurements using electron backscatter diffraction - Part 2: Experimental demonstration
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DOI：
10.1016/j.ultramic.2013.08.006
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发表时间：
2013-12-01
期刊：
影响因子：
2.2
通讯作者：
Wilkinson, A. J.
中科院分区：
文献类型：
--
作者：
Britton, T. B.;Jiang, J.;Wilkinson, A. J.
用高分辨率EBSD对硅中显微硬度测试后的残余压痕进行了测绘，以揭示残余弹性应变和晶格旋转场。同一地区的映射已进行可变图案分箱和曝光时间，以揭示定性和定量的差异，减少图案的大小和曝光时间。这些领域的二维“图像”图表明，定性评估的形状和大小的领域可以进行多达4 × 4的合并。然而，使用线扫描的定量评估表明，使用最小的图案分箱和长曝光时间可以获得最平滑的轮廓。为了与这些实验图进行比较和对比，使用连续损伤塑性材料定律进行了有限元分析，该定律已独立校准到Si [9]。本构关系包括压缩时的各向同性硬化和拉伸时的各向同性硬化和损伤。为了准确地捕获在压痕过程中通过压痕部位周围裂纹的成核和传播而产生的局部损伤，沿沿着经历最大牵引力的平面之间的界面分配粘性元件。压头周围的残余应变状态和裂纹尺寸与实验测量值吻合得很好。(C)2013年爱思唯尔B。V.保留所有权利。
The residual impression after performing a microhardness indent in silicon has been mapped with high resolution EBSD to reveal residual elastic strain and lattice rotation fields. Mapping of the same area has been performed with variable pattern binning and exposure times to reveal the qualitative and quantitative differences resulting from reducing the pattern size and exposure time. Two dimension 'image' plots of these fields indicate that qualitative assessment of the shape and size of the fields can be performed with as much as 4 x 4 binning. However, quantitative assessment using line scans reveals that the smoothest profile can be obtained using minimal pattern binning and long exposure times. To compare and contrast with these experimental maps, finite element analysis has been performed using a continuum damage-plasticity material law which has been independently calibrated to Si [9]. The constitutive law incorporates isotropic hardening in compression, and isotropic hardening and damage in tension. To accurately capture the localised damage which develops during indentation via the nucleation and propagation of cracks around the indentation site cohesive elements were assigned along the interfaces between the planes which experience the maximum traction. The residual strain state around the indenter and the size of the cracks agree very well with the experimentally measured value. (C) 2013 Elsevier B. V. All rights reserved.