Cyclic deformation and fatigue damage behavior of Cu monocrystals, bicrystals and tricrystals

In the present work, the cyclic deformation behavior of Cu single crystals oriented for double- and multiple slip as well as Cu bicrystals and tricrys tals was investigated under constant plastic strain control at room tempera ture in air. The main objectives of the study are: (1) to find out the effe cts of crystallographic orientation and grain boundary (GB) on the cyclic s tress-strain (CSS) curves; (2) to compare the cyclic deformation behavior o f the double-, multiple-slip crystals, bicrystals and tricrystals with that of single-slip oriented crystals and to correlate the results with those o f polycrystals; (3) to examine the corresponding dislocation structures; (4 ) to investigate the interactions of persistent slip bands (PSBs) with GBs and triple joint (TJ) as well as intergranular fatigue cracking in Cu bicry stals and tricrystals.