Internal Friction of Polycrystalline Rhenium Following Torsional Deformation at Liquid Nitrogen Temperature

Aging treatments at room temperature, following deformation at liquid nitrogen temperature on a polycrystalline h.c.p. rhenium specimen results in a partial recovery of the damping and the modulus defect, together with the introduction of a relaxation peak. The experimental observations are interpreted in terms of dislocations moving, during aging, from a position, non‐parallel with a Peierls valley, into a position in a Peierls valley and hence changing their behaviour from string‐like to double‐kink generation conditioned.