RELATIONSHIP BETWEEN STRESS AND DISLOCATION-STRUCTURE OF FATIGUED POLYCRYSTALLINE COPPER

The relationship between the saturated stress and the dislocation stru ctures in fatigued polycrystalline copper is quantitatively evaluated from region A to region C. It is revealed that the saturated stress is linearly related to the inverse spacing between the dislocation: wall s. The value of the coefficient K in the meshlength theory is determin ed to be equal to 7.89 and is in agreement with the value of 8 obtaine d from theoretical considerations. In addition, the relationship betwe en the saturated back stress and dislocation structures is established . The saturated back stress is found to be half of the stress to bow o ut the dislocation from the dipolar walls. Furthermore, the stress in the PSB structures is examined. It is found that the meshlength theory provides a good prediction of the stress in the PSBs formed at room t emperature.