Solution-precipitation creep—continuum mechanical formulation and micromechanical modelling

Abstract

Solution-precipitation creep is considered to be one of the major deformation mechanisms of polycrystalline materials containing a fluid phase. Geological evidence suggests that it is particularly important for processes occurring in the earth crust at very low deviatoric stress. We develop a continuum mechanical model based on the assumption that the energy dissipated during deformation depends solely on the normal velocity of the grain boundary movement due to precipitation or solution of material and the velocity of material transport within the grain interfaces. This approach allows us to identify the driving force responsible for solution-precipitation creep in an unambiguous way. Moreover, a micromechanical approach based on an averaging assumption of a Voigt/Sachs type is given.