MAGNETIC-MEMORY EFFECTS IN HIGH-PURITY BERYLLIUM

摘要

We study the magnesium-thermal beryllium condensate in the course of natural aging after several procedures of treatment by weak constant magnetic fields. The amplitude-time dependences of the effective shear modulus (G(ef) similar to f(2)), low-frequency internal friction, the parameter r, and the ratio of dislocation velocities V-afef/V-0 are analyzed. It was revealed that the hysteresis in the f (2)(gamma) curves disappears after similar to 120 h of natural aging and the sign of r(gamma) and V-afef/V-0(gamma) is inverted. The nature of the detected effects is connected with the appearance of microcracks in the stage of elastic deformation and their healing as a result of the viscous motion of unpinned dislocations in the field of point defects in the basal slip plane.