In-situ elastic strain mapping during micromechanical testing using EBSD

Compared to more commonly used strain measurement techniques, electron backscatter diffraction (EBSD) offers improved spatial resolution and measurement sensitivity. Additionally, EBSD can provide the full deformation tensor, whereas other techniques, such as digital image correlation (DIC), are limited to only in-plane strains and rotations. In this work, EBSD was used to measure strains and rotations in-situ during testing of a single-crystal silicon micromechanical test specimen. The theta-like specimen geometry was chosen due to the complex and spatially-varying strain states that exist in the circular frame of the sample during testing, as well as the nominally uniform strains in the central web. Full-field strain maps were generated for each strain and rotation component and compared to those from finite element analyses (FEA), showing strong agreement in all cases. Additionally, potential sources of error and their impact on both measurement accuracy and uncertainty are discussed.