Structure and properties of Ni 60(Nb 100− xTa x) 34Sn 6 bulk metallic glass alloys

Abstract

Refractory bulk metallic glasses and bulk metallic glass composites are formed in quaternary Ni–Nb–Ta–Sn alloy system. Alloys of composition Ni 60(Nb 100− x Ta x ) 34Sn 6 ( x = 20, 40, 60, 80) alloys were prepared by injection-casting the molten alloys into copper molds. Glassy alloys are formed in the thickness of half mm strips. With thicker strips (e.g., 1 mm), Nb 2O 5 and Ni 3Sn phases and the amorphous phase form an in situ composite. Glass transition temperatures, crystallization temperatures, and Δ T x , defined as T x1 − T g ( T x1 : first crystallization temperature, T g: glass transition temperature) of the alloys increase dramatically with increasing Ta contents. These refractory bulk amorphous alloys exhibit high Young’s modulus (155–170 GPa), shear modulus (56–63 GPa), and estimated yield strength (3–3.6 GPa).