Folding in FCC metal single crystals under compression

Abstract

Results of the analysis of folding during compression deformation of metals with fcc lattice are presented. Single crystals with orientations at angles of the standard stereographic triangle and different crystallographic orientations of lateral faces have been studied. It has been found that the major factor affecting the folding intensity is the slip plane shear with respect to lateral faces. Such a shear results in face bending and the formation of fold systems in maximum curvature regions. It has been shown that, among all considered orientations, the maximum susceptibility to the formation of different folds is inherent in single crystals with \(\bar 1\) compression axis orientation. For this orientation, the development of shear and rotational components during folding is traced by interference microscopy and electron backscatter diffraction methods. It has been found that an excess dislocation density is accumulated when shear is activated in the folding region, which results in an increase in fold misorientation. The activation of this process in fcc metals is promoted by an increase in the homologous deformation temperature and stacking fault energy.