Direct observation of plastic deformation in iron–3% silicon single crystal by in situ nanoindentation in transmission electron microscopy

By making an indentation into a body-centered cubic single crystal of Fe–3% Si through the in situ nanoindentation in a transmission electron microscopy technique, we found that dislocations formed during the early stage involved not distinguishable pop-ins but small load fluctuations. The pop-in behavior was connected with the change of dislocation structures. The phenomenon was explained by the conventional strain rate model.