Crystallochemistry of Amorphous State in Ni(Co, Fe)-Nb(V, Ta, Mo+Zr) Alloy Systems

Abstract

Effects of the crystallochemical factors on amorphous state formation in the Ni−Nb-based systems are studied. Alloys with compositions (Ni, Co, Fe)−(Nb, Ta, V, Mo+Zr) are prepared by rapid melt quenching method with various cooling rates. It was found that at given preparation conditions and at certain atomic size factor, glass forming ability depends on factor of electron concentration was defined as number of s+d electrons per atom. Atomic size factor is necessary take into account, too. High glass forming ability of Ni−Nb alloys are attributed to formation possibility of two distinct E93 type phases.