Residual resistivity ratio and plasticity of high-purity NiAl single crystals

摘要

High-purity NiAl single crystals have been prepared by crucible-free inductive zone melting under an Ar atmosphere. The influence of an annealing treatment (1073 K for 24 h) on the residual resistivity ratio and on the plasticity was studied for these samples. For stoichiometric single crystals the residual resistivity ratio increases a factor of about two to three during the annealing treatment and the annealed specimens show a higher ductility. Both improvements can be explained by the formation of vacancy clusters during the annealing treatment as observed by transmission electron microscopy investigations.