Scanning electron microscopy for quantitative small and large deformation measurements - part II: Experimental validation for magnifications from 200 to 10,000

A combination of drift distortion removal and spatial distortion removal are performed to correct Scanning Electron Microscope (SEM) images at both x 200 and x 10,000 magnification. Using multiple, time-spaced images and in-plane rigid body motions to extract the relative displacement field throughout the imaging process, results from numerical simulations clearly demonstrate that the correction procedures successfully remove both drift and spatial distortions with errors on the order of +/- 0.02 pixels. A series of 2D translation and tensile loading experiments are performed in an SEM for magnifications at x 200 and x 10,000, where both the drift and spatial distortion removal methods described above are applied to correct the digital images and improve the accuracy of measurements obtained using 2D-DIC. Results from translation and loading experiments indicate that (a) the fully corrected displacement components have nearly random variability with standard deviation of 0.02 pixels (approximate to 25 nm at x 200 and approximate to 0.5 nm at x 10,000) in each displacement component and (b) the measured strain fields are unbiased and in excellent agreement with expected results, with a spatial resolution of 43 pixels (approximate to 54 mu m at x200 and approximate to 1.1 mu m at x 10,000) and a standard deviation on the order of 6 x 10(-5) for each component.