ABSTRACT
CHAPTER 12
CRYSTAL PLASTICITY
Previous chapters were devoted to phenomenological theory of plasticity, in
which microscopic structure and mechanisms causing plastic ow were not
included explicitly, but only implicitly through macroscopic variables, such
as the generalized plastic strain, the radius of the yield surface, or the back
stress. This chapter deals with plastic deformation of single crystals. The
discrete dislocation substructure is still ignored, but plastic deformation is
considered to occur in the form of smooth shearing on the slip planes and
in the slip directions. Such continuum model of slip has its origin in the
pioneering work of Taylor (1938). The model was further developed by Hill
(1966) in the case of elastoplastic deformation with small elastic component
of deformation, and by Rice (1971), Kratochvil (1971), Hill and Rice (1972),
Havner (1973), Mandel (1974), Asaro and Rice (1977), and Hill and Havner
(1982) in the case of nite elastic and plastic deformations. Since the theory
explicitly accounts for the specic microscopic process (crystallographic slip),
it is also referred to as the physical theory of plasticity. Optical micrographs
of crystallographic slip are shown in Fig. 12.1. Other mechanisms of plastic
deformation, such as twinning, displacive (martensitic) transformations, and
diusional processes are not considered in this chapter.
