In-situ observations and quantification of twin boundary mobility in polycrystalline magnesium

In-situ microtensile experiments were conducted on commercially pure polycrystalline magnesium to examine the motion of twin boundaries (TBs) during deformation in a scanning electron microscope. The nature of the boundaries is identified using electron back scattering diffraction (EBSD) analysis. TB displacement is continuously recorded during the deformation and the TB velocity is computed from the real time images and time data. The TB velocity is observed to monotonically increase with the applied stress and eventually reach a speed of 35 nm/s.