Adsorption at grain boundaries and its effect on decohesion

Abstract

The energy of decohesion of a grain boundary as influenced by solute adsorption is considered. In the nearly reversible case, the change in this energy, and hence of the likelihood of decohesion, is developed in terms of the thermodynamic description of Gibbs. A distinction is made between the normal separation of a grain boundary, where cohesive force and cohesive energy are interrelated and relevant, and separation at a crack tip where cohesive force is not relevant but where a lattice trapping barrier exists. A number of irreversible decohesion phenomena that can be influenced by solute adsorption are also discussed.