Quinta D A Fonseca J, Mummery P M, Withers P J
Manchester Materials Science Centre, Grosvenor Street, Manchester M1 7HS, U.K.
J Microsc. 2005 Apr;218(Pt 1):9-21. doi: 10.1111/j.1365-2818.2005.01461.x.
Optical correlation is an emerging strain-mapping technique that allows full-field surface strain mapping by comparing the images of the same region before, during and after deformation. The fundamental aspects of optical correlation are presented, with emphasis on the applicability of the technique to the analysis of micrographs obtained during in situ deformation studies. Without considering specific algorithms, this paper discusses important practical issues such as accuracy and spatial resolution and how these are affected by image quality and other experimental difficulties. The technique was used to analyse image sequences obtained during in situ deformation tensile tests on two very different materials: antler bone and ferritic steel. As the technique does not require patterns or coatings to be applied on the surface of interest, the strain maps obtained could be used to relate strain heterogeneity to the underlying microstructure.
光学相关性是一种新兴的应变映射技术，它通过比较同一区域在变形前、变形过程中和变形后的图像来实现全场表面应变映射。本文介绍了光学相关性的基本原理，重点讨论了该技术在原位变形研究中所获得的显微照片分析中的适用性。本文不考虑具体算法，而是讨论了诸如精度和空间分辨率等重要的实际问题，以及这些问题如何受到图像质量和其他实验困难的影响。该技术被用于分析在两种截然不同的材料——鹿角骨和铁素体钢——上进行的原位变形拉伸试验过程中获得的图像序列。由于该技术不需要在感兴趣的表面上施加图案或涂层，因此所获得的应变图可用于将应变不均匀性与潜在微观结构联系起来。
