EFFECTS OF CRYSTALLOGRAPHIC ORIENTATION AND GRAIN BOUNDARY ON CYCLIC DEFORMATION IN COPPER CRYSTALS

摘要

The cyclic deformation behavior of double or multiple slip copper single crystals and copper bicrystals with either parallel, perpendicular or tilting grain boundaries has been investigated. The main objectives of the study are: (1) to establish the CSS curves and find out the effects of crystallographic orientation and grain boundary on the CSS curve; (2) to compare the cyclic deformation behavior of the double-, multiple-slip crystals and bicrystals with that of single-slip oriented crystals and to correlate the results with those of polycrystals; (3) to examine the corresponding dislocation structures; (4) to investigate the interaction of PSBs with GBs and (5) to examine the intergranular fatigue cracking.