Understanding the 3D growth and morphology of deformation twins using in-situ DFXM and topotomography

The aim of this experiment is to investigate twinning in magnesium alloys using dark-field X-ray microscopy (DFXM) and topotomography during mechanical loading. At one-third the weight of aluminum, magnesium (Mg) alloys hold significant promise for reducing the emissions of automobiles and aircrafts via lightweighting. Mg will both plastically slip and twin in response to a mechanical load. In a past DFXM experiment, we characterized twinning in Mg-4Al with in-situ DFXM using a miniature loading stage. We observed the accumulation of dislocations (the precursor to cracking) at twin-grain and twin-twin junctions. We also demonstrated that it is possible to characterize twin growth in 3D (the first experimental observation of its kind) using these methods, but we were only able to characterize three load steps. Here, we aim to characterize the sequential growth of deformation twins in 3D using a new approach that include motor-actuated loading, and combining DFXM with topotomography.