Effects of grain boundaries on cyclic deformation behavior of copper bicrystals and columnar crystals

摘要

In order to reveal the effects of grain boundaries (GBs), the cyclic deformation behavior of a copper columnar crystal containing low-angle GBs, a really grown copper bicrystal RB and a combined columnar crystal exhibited. The results show that the cyclic stress-strain curve(CSSC) of the copper columnar crystal exhibited a plateau region with saturation resolved shear stress of about 29 MPa over a plastic resolved shear strain range from 6.5 X 10`-4 to 4.7 X 10~-3. The electron channeling contrast technique in scanning electron microscopy(SEM-ECC) was applied to observe the cyclically saturated dislocation structures and persistent slip bands(PSBs).