On the reverse mode of fcc deformation twinning

The reverse mode of face-centered cubic (fcc) deformation twinning is found to be responsible for the formation of kink bands during compression of pre-twinned Cu-8.5 at.% Al single crystals. The formation of kink bands is described, and a very high level of activity of the reverse fcc twinning is established. It is also found that the reverse twinning is driven at a critical resolved shear stress lower by well over factor of 2 in comparison with the direct twinning mode operating in Cu-8.5 at.% Al single crystals during primary tensile deformation. This discovery of the reversible plastic mode of fcc twinning should find important application in the theory and modeling of large plastic deformations of fcc materials, including cyclic deformation phenomena. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.