Site preference of ternary additions in γ-TiAl: A density-functional cluster-model study

Abstract

The site preference of ternary additions Mg, V, Cr, Mn, Ga, and Mo in \ensuremath{\gamma}-TiAl intermetallic compounds is studied using the discrete-variational local-density-functional method with cluster models. The relations of the site preference of ternary additions with the compositions of the host elements and with the concentrations of the additions themselves in the host are obtained. The results explain satisfactorily the experimental observations and are discussed with the effects of ternary additions in improving the ductility of \ensuremath{\gamma}-TiAl.