Incipient plasticity during nanoindentation at elevated temperatures

The onset of plastic deformation during nanoindentation is studied, focusing upon the effects of temperature variation. Indentations on pure (100)-oriented platinum at 20, 100, and 200°C reveal that the transition from elastic to plastic deformation occurs at progressively lower stress levels as temperature is increased. Additionally, it is shown that during plastic deformation, higher temperatures promote the discretization of plasticity into sharp bursts of activity. These results are in line with expectations for stress-biased, thermally activated deformation processes such as the nucleation of dislocations or the abrupt release of dislocation entanglements.