Ni-based bulk amorphous alloys in the Ni-Ti-Zr-Si system

We report on the fabrication and properties of the new Ni-based bulk amorphous alloys in the Ni-Ti-Zr-Si system that have high glass forming ability (GFA) and large undercooled region (ΔT_X), which corresponds to the temperature difference between glass transition temperature and the onset temperature of a first crystallization event. The compositional range for the formation of the amorphous alloys that have large ΔT_X (>30K) is defined in the pseudo-ternary phase diagram Ni-(Ti,Zr)-Si. Some alloys can be fabricated as fully amorphous rods 2 mm diameter through an injection casting method. Si effects on the crystallization behavior of these new Ni-based amorphous alloys are also investigated and related to the GFA and the ΔT_X.