Slip System Selection and Taylor Factor Evolution in FCC Metals

Abstract

The prediction of active slip systems during plastic deformation is analyzed for FCC metals under various deformation conditions (uniaxial, plane strain). The analysis reveals the orientation dependent stress contributions (Taylor factor and similar) and metallurgical effects of dislocation interaction, resulting in strain hardening and recrystallization mechanisms, i.e. nucleation and driving force for grain boundary motion. In technical terms the orientation effective strength as quantified by the Schmid- or Taylor-factor is of main interest for mechanical and anisotropic behavior of metal parts. The activated {111} slip systems and the relative amount of glide is evaluated for the case of stable orientations in uniaxial (tension, compression, bi-axial loading) and plane strain deformation (sheet rolling) in FCC metals. The classical Taylor analysis and related texture simulation models are applied under conditions of full and various relaxed constraints, considering the various boundary conditions, as described in the classical Sachs and Taylor models and derived "Relaxed Constraints" (RC) or "Grain Inter-Action" (GIA) models. These models which describe the principle effects slip system selection during plastic deformation and related texture formation and orientation stability have been analyzed for active slip systems and resulting stress contributions of stable orientations and textures of FCC metals.