Abstract
Crystals of copper and nickel aligned with the tensile axis parallel to [001] have been deformed to various stress levels at 78 K and ambient temperature. After 1 h anneals at high temperature the crystals were pulled again at room temperature to determine their yield stresses. Crystals deformed to high stresses give almost identical isochronal recovery curves (Region III), whereas those stressed to Stage-II deformation exhibit structure-sensitivity (Region II). In the case of copper, where recovery in Region II can be associated with the annealing of monopole dislocations, isothermal investigation reveals that the activation energy is higher than that for self-diffusion. For the comparable region in nickel a similar effect is found. The observed kinetics is consistent with the Frank network growth model proposed by Friedel.
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