On the application of digital optical microscopy in the study of materials structure and deformation

Digital optical microscopy (DOM) has revolutionised many aspects of industrial inspection and metrology through its ability to acquire and manipulate accurate images of samples using the power of computers. We report the application of HokusAI®, a suite of techniques for digital optical microscopy developed at the Hierarchically Structured Materials (HSM) lab at the Skolkovo Institute of Science and Technology (Skoltech), to elasto-plastic deformation and fracture mechanics analysis of samples of stainless steel AISI 304. Focus Stacking Optical Microscopy (FSOM) is combined with image stitching and Digital Image Correlation (DIC) to collect exhaustive and precise description of sample geometry, surface roughness, fracture surface morphology, and the evolution of deformation during in situ tensile testing. The implications of these advances for the analysis of deformation and fracture of advanced engineering materials are discussed.