Detwinning-twinning behavior during compression of face-centered cubic twin-matrix layered microstructure

Abstract

In this paper, we have examined the mechanical response of a face-centered cubic layered twin – matrix system, which has been generated in Cu–Al alloy single crystal. This kind of microstructure was obtained by specially designed uniaxial tension experiments of Cu-9at.%Al single crystals oriented for “easy” glide. It has been shown, that detwinning system, which operates along the twinning plane, may at specific crystallographic conditions totally dominate the process of plastic deformation. The detwinning system was activated in a confined area that creates a localized deformation regions in the form of kink bands that were found to be hierarchical in formation (i.e. higher order kinking within already existing kink bands). This mode of plastic deformation generates lattice rotation that was identified to occur around normal to the plane of shear of the active detwinning system. Hence, the paper gives direct experimental prove of the importance of detwinning systems on the mechanical properties and deformation texture analysis of face-centered cubic materials.