Effect of Impurity Bonding on Grain-Boundary Embrittlement

Abstract

We have explicitly tested, using pseudopotential total-energy techniques, the effect of two representative embrittling impurities on the grain-boundary cohesion of a metal. We find that substitutional Ge and As impurities increase the Al[111] interlayer energy of cohesion both at the impurity-doped layer and one layer into the bulk. Our calculations do not support either the first-layer or the second-layer decohesion models of impurity-promoted grain-boundary embrittlement.