High-Resolution Deformation Mapping Across Large Fields of View Using Scanning Electron Microscopy and Digital Image Correlation

TitleHigh-Resolution Deformation Mapping Across Large Fields of View Using Scanning Electron Microscopy and Digital Image Correlation
Publication TypeJournal Article
Year of Publication2018
AuthorsChen, Z., W. Lenthe, J.C. Stinville, M. Echlin, T.M. Pollock, and S. Daly
JournalExperimental Mechanics
Pagination1-15
Date Published08/2018
Abstract

This paper details the creation of experimental and computational frameworks to capture high-resolution, microscale deformation mechanisms and their relation to microstructure over large (mm-scale) fields of view. Scanning electron microscopy with custom automation and external beam control was used to capture 209 low-distortion micrographs of 360 μm × 360 μm each, that were individually correlated using digital image correlation to obtain displacement/strain fields with a spatial resolution of 0.44 μm. Displacement and strain fields, as well as secondary electron images, were subsequently stitched to create a 5.7 mm × 3.4 mm field of view containing 100 million (7678 × 13,004) data points. This approach was demonstrated on Mg WE43 under uniaxial compression, where effective strain was shown to be relatively constant with respect to distance from the grain boundary, and a noticeable increase in the effective strain was found with an increase in the basal Schmid factor. The ability to obtain high-resolution deformations over statistically relevant fields of view enables large data analytics to examine interactions between microstructure, microscale strain localizations, and macroscopic properties.