In the present work we analyze the composition ranges over which bulk metallic glasses (BMGs) are produced in ternary, quaternary, and quinary amorphous alloys. The maximum diameter of the sample over which an amorphous structure can be retained, referred to as the critical diameter, Dc, is consistently large over specific composition ranges. For ternary BMGs, these most stable glasses are centered around the compositions, in decreasing order of accompanying Dc: A44B38C18, A 44B43C13, A65B25C 10, A56B32C12, A55B 28C17, A70B20C10, and A65B20C15. As a general trend, the most stable glasses have the lowest concentrations of solvent atoms. Structural analysis using the efficient cluster packing model suggests that the best ternary glasses are near the isostructural composition, which represents the maximum degree of atomic confusion. Both MDc and Δ Tx = Tx - Tg, the difference between the crystallization and glass transition temperatures, are larger in quaternary and quinary systems relative to typical values for ternary BMGs. Glass-forming ability increases with complexity of the alloy, i.e., increasing number of alloying elements. The above results shed some light not only on compositional dependence of the formation of glassy phase but also its relation to the structure of the glasses.
ASJC Scopus subject areas
- Physics and Astronomy(all)