Synthesis and thermal stability of new Ni-based bulk glassy alloy with excellent mechanical properties

Abstract

The thermal stability, glass-forming ability (GFA) and mechanical properties of the Ni-Ta-Ti and Ni-Ta-Ti-Zr glassy alloys have been investigated. As the Ti content increases, the supercooled liquid region ΔT x(= T x - T g) and reduced glass transition temperature (T g/T l) of Ni 60Ta 40-xTi x glassy alloys increase, showing maximum values of 63 K at 20%Ti and 0.59 at 25 at%Ti, respectively, and then gradually decrease. The addition of Zr to Ni-Ta-Ti alloys is effective for the increase in ΔT x and T g/T l. The maximum ΔT x and T g/T l values of 73 K and 0.60, respectively, are obtained for Ni 60Ta 15Ti 20Zr 5 alloy. The Ni-Ta-Ti-Zr glassy alloys were formed in the rod form with diameters of over 1.0mm by copper mold casting. The Ni-Ta-Ti-Zr bulk glassy alloys exhibit excellent mechanical properties, i.e., the compressive fracture strength (σ c, f) of 3180-3220 MPa and the compressive plastic elongation (ε c, p) of 0.2-0.4%. © 2006 The Japan Institute of Metals.