Low‐temperature relaxation peaks in zirconium deformed at 8 K

The internal friction spectrum of pure zirconium, deformed at 8 K, shows a number of peaks which are identical to those observed following plastic deformation at room temperature. Additionally, a damping peak is observed at about 280 K (for a frequency of about 80 Hz) in specimens characterized by the presence of a high concentration of {1121} type twins, which are therefore believed to be responsible for this peak. A model is presented to describe the twin boundaries as a collection of partial dislocations, the stress induced motion of which leads to the observed internal friction peak.