Adsorption-induced losses in interfacial cohesion

Abstract

A model for interfacial cohesion is developed which describes the loss in the strength of an interface owing to the segregation and adsorption of impurities on it. Distinctions are made between interface separations that occur too rapidly for any significant redistribution of adsorbing matter to take place, which are suggested conform to many actual fracture processes, and separations that are slow enough to allow full adsorption equilibrium. Expressions for the total work of complete decohesion are presented for both cases. The results are applied to well known model adsorption isotherms and some experimental data for grain boundary adsorption of phosphorus in iron are analysed with respect to the losses in intergranular cohesion.