Sibley School of Mechanical and Aerospace Engineering, 196 Rhodes Hall, Cornell University, Ithaca, NY 14853, USA.
J Synchrotron Radiat. 2012 Mar;19(Pt 2):237-44. doi: 10.1107/S0909049511050400. Epub 2012 Jan 7.
X-ray microdiffraction is a powerful technique for conducting high-spatial-resolution lattice strain measurements. However, there has been limited validation of the technique to date. An experiment was conducted at the Advanced Light Source to assess the uncertainty of deviatoric lattice strains measured using polychromatic X-ray microdiffraction. It is shown that the measurement uncertainty is different for each component of the deviatoric lattice strain tensor. Monte Carlo simulations of the experiment are used to explain the differences in uncertainty. The simulations point to the existence of spurious deformation modes that arise erroneously in the strain calculation owing to measurement noise and limited pole figure coverage. Methods for reducing measurement uncertainty are proposed.
X 射线微衍射是一种用于进行高空间分辨率晶格应变测量的强大技术。然而，迄今为止，该技术的验证非常有限。本实验在先进光源中进行，以评估使用多色 X 射线微衍射测量的偏差晶格应变的不确定度。结果表明，各向异性晶格应变张量的每个分量的测量不确定度都不同。对实验的蒙特卡罗模拟用于解释不确定性的差异。这些模拟表明，由于测量噪声和极图覆盖范围有限，应变计算中会错误地出现虚假变形模式。提出了降低测量不确定性的方法。
