Phase separation in Ni–Nb–Y metallic glasses

The ternary system Ni–Nb–Y exhibits an extended miscibility gap in the equilibrium liquid. The decomposition of the liquid can be used to prepare phase-separated Ni–Nb–Y glasses by means of rapid quenching of the melt. Phase separation and structure formation take place during quenching in the undercooled liquid. The temperature dependence of the critical temperature of liquid–liquid phase separation TC determines essentially the quenched in microstructures. For Ni contents <60 at.% coarsened hierarchical microstructures of two-phase glasses are formed. For Ni contents >60 at.% early stages of decomposition are obtained with correlation lengths in the nanometer-range. In situ small angle X-ray scattering at elevated temperatures gives evidence of the spinodal character of the decomposition.