Annealing Effects of Mechanical Properties in Electron-Irradiated Copper Single Crystals at 90 K

Isochronal annealing effects on the activation volume of plastic defor-mation in Cu after 90 K irradiation were investigated in the temperature range between 90 and 340 K. The activation volume slightly decreases with increasing annealing temperature between 90 and 200 K, then keeps a constant value in the annealing-temperatures between 200 and 270 K,and above 270 K increases with a rise in the annealing temperature. The an- nealing temperature dependence of the activation volume shows a good cor-respondence to the behavior of the yield stress on the annealing experiment. Specimen surface after plastic deformation was observed by using an op-tical microscope. The surface shows coarse slip lines associated with a yield drop phenomenon. Dislocation configurations were observed by using a 1 MeV HVEM. Dislocations show zigzag or bowed out patterns. These results suggest that defects remaining after the annealing are work-ing as strong barriers for motion of dislocations. Some annealin