Stress relaxation in aluminium under cyclic electron irradiation conditions

Stress relaxation in aluminium with small manganese additions (0.02 at.%) at 303-363 K temperatures under conditions of cyclic electron irradiation (2 MeV, 6.75x1013 cm-2 x s-1) is studied. It is found that when an electron beam is on, sharp acceleration of relaxation deformation (3-10 times) with a subsequent smooth decrease of the effect is observed. When the beam is off, the relaxation rate is gradually decreased approximately by a factor of 1.5. The observed effects are explained by the ''dynamic preference'' effect - advantageous absorption of more mobile interstitial atoms by dislocations