ORIENTATION SPLITTING OF CUBE-ORIENTED FACE-CENTERED CUBIC-CRYSTALS IN PLANE-STRAIN COMPRESSION

Orientation splitting of cube-oriented f.c.c. crystals during plane strain compression is analysed by assuming the development of deformation bands in the direction of extension. The bands are considered to undergo the macroscopic normal strain components but are allowed to shear in opposite senses along the elongation direction (local relaxed constraints model). It is shown that this local deformation banding leads, for both the (001)[010] and (001)[110] orientations, to large lattice rotations of opposite sign about the transverse axis and hence the formation of transition bands. Analytical expressions are derived for the lattice rotations up to true strains of about unity. Experimental plane strain compression tests on (001)[010] and (001)[110] aluminium single crystals confirm the predicted behaviour and indicate the spatial distribution of the bands and their slip systems. It is shown that the bands in the (001)[110] orientation are characterized by double coplanar slip while those in the cube crystals behave according to a single-slip model.