Strong Crystal Size Effect on Deformation Twinning Observed Using Hysitron's TEM Picoindenter - PI 95

This video shows the in situ compression of the 250 nm, <0001> oriented Ti-5at% Al single crystal pillar in TEM. Five consecutive tests have been performed. Ordinary dislocation plasticity and mushroom-like deformation geometry characterize the entire deformation process. This is in sharp contrast with that of bulk Ti-5at% Al in which deformation twinning are known to dominate the plastic deformation and obvious shear offset are frequently observed. (Yu et al, Nature, 2010)