Segregation inhibited grain coarsening in nanocrystalline alloys

Abstract

It will be shown, in the framework of a general statistical (atomistic) treatment, that segregation inhibited grain coarsening in binary nanocrystalline alloys can be described by analytical expressions, if the effect can be attained with highly saturated grain boundaries. Relatively simple relations describing the temperature dependence of the stabilized grain-boundary fraction will be derived. The validity conditions of the relation proposed very recently by R. Kirchheim [Acta Mater. 50, 413 (2002)] are also analyzed. Our conclusions are compared with experimental results and the reliability of the few experimental data, known at present, will be discussed as well.