Department of Materials, University of Oxford, Parks Road, Oxford, UK.
Ultramicroscopy. 2011 Jul;111(8):1395-404. doi: 10.1016/j.ultramic.2011.05.007. Epub 2011 May 27.
A set of dynamically simulated electron backscatter patterns (EBSPs) for α-Ti crystals progressively rotated by 1° steps were analysed using cross-correlation to determine image shifts from which strains and rotations were calculated. At larger rotations the cross-correlation fails in certain regions of the EBSP where large shifts are generated. These incorrect shifts prevent standard least square error procedures from obtaining a valid solution for the strain and rotation, where the applied rotation exceeds ∼ 8°. Using a robust iterative fitting routine reliable strains and rotations can be obtained for applied rotations of up to and including ∼ 11° even though some image shifts are measured incorrectly. Finally, high resolution electron backscatter diffraction has been used to analyse the residual elastic strain, lattice rotations and density of stored geometrically necessary dislocations in a sample of copper deformed to 10% total strain. The robust iterative fitting analysis allows reliable analysis of a larger proportion of the map, the difference being most obviously beneficial in regions where significant lattice rotations have been generated.
一组通过 1°逐步旋转的α-Ti 晶体的动态模拟电子背散射花样（EBSP）被用来进行互相关分析，以确定图像的位移，从而计算应变和旋转。在较大的旋转角度下，互相关在 EBSP 的某些区域失效，这些区域会产生较大的位移。这些不正确的位移会阻止标准的最小二乘误差程序获得有效解，因为应用的旋转超过约 8°。使用稳健的迭代拟合程序，可以获得高达 11°甚至更高的应用旋转的可靠应变和旋转，尽管一些图像位移被测量不正确。最后，高分辨率电子背散射衍射被用来分析在铜样品中变形到 10%总应变时残余弹性应变、晶格旋转和储存几何必需位错的密度。稳健的迭代拟合分析允许对更大比例的图谱进行可靠的分析，这在产生显著晶格旋转的区域最为明显。
