Formation and properties of new Ni–Ta-based bulk glassy alloys with large supercooled liquid region

Abstract

The addition of Ti and Zr to Ni–Ta binary alloys is effective for the increase in stabilization of supercooled liquid and glass-forming ability (GFA). The maximum supercooled liquid region (Δ T x) of 73 K and the reduced glass transition temperature ( T rg) of 0.60 were obtained for Ni 60Ta 15Ti 20Zr 5, leading to the formation of the bulk glassy alloys. The subsequent addition of appropriate amounts of Co and Cu to Ni–Ta–Ti–Zr alloys lowers liquidus temperature ( T l), resulting in the improvement of GFA. The best GFA was obtained for Ni 48Ta 15Ti 20Zr 5Co 7Cu 5 alloy which was located near the eutectic composition of the multi-component alloys, and the glassy alloy samples with diameters up to 1.5 mm were fabricated. The new Ni–Ta-based bulk glassy alloys exhibit large Δ T x of 72–84 K, high fracture strength of over 3050 MPa with a distinct plastic strain, and excellent corrosion resistance in 1N HCl solution.