Compositional Dependence of the Compressive Yield Strength of Fe-Nb(-Al) and Co-Nb Laves Phases

摘要

Large, defect-free single-phase samples of the hexagonal C14 NbFe_2 and Nb(Fe,Al)_2, and the cubic C15 NbCo_2 Laves phases have been produced by a modified levitation melting technique. The compressive strength of NbFe_2 and NbCo_2 has been determined in dependence on the Nb content, that of Nb(Fe,Al)2 in dependence on the Al content. The binary phases did not show either a maximum (defect softening) or minimum (defect hardening) in strength when the Nb content was varied. Instead, for both phases an increase of the compressive strength with increasing Nb content is observed.