Melt fragility of near-intermetallic composition.

The dynamic viscosities of In-Bi and Ag-Yb alloy systems are measured by the torsional oscillation viscometer and the corresponding melt fragilities (M) are calculated from the temperature dependence of viscosities fitted by the Arrhenius equation. It was found that the melt fragility of the intermetallics is larger than that of the alloys with near-intermetallic compositions, but is smaller than that of the alloys with near-intermetallic compositions with a peritectic reaction. From the thermodynamics and kinetics points of view, the origins for the compositions near intermetallics as potential hosts of glass formers were well demonstrated. Our study confirms the universality of melt fragility and gives implications on the physical mechanisms for the glass forming alloys. [ABSTRACT FROM AUTHOR]