Unusual Glass-Forming Ability of New Zr-Cu-Based Bulk Glassy Alloys Containing an Immiscible Element Pair

We herein report the unusual glass-forming ability (GFA) of a new series of quinary Zr48Cu36-xNixAg8Al8 (0 < x <= 10 in at%) alloys, in which Ni-Ag element pair is in immiscible system with a large positive beat of mixing. Addition of Ni lowers the liquidus temperature, of the quaternary Zr48Cu36Ag8Al8 alloy. By copper mold casting, an as-cast glassy rod with a diameter of 30mm can be easily obtained for the representative alloy Zr48Cu32Ni4Ag8Al8. The possible reasons for the excellent GFA of the new quinary alloys with an immiscible element pair are discussed based on the atomic size distribution, chemical compatibility among the components and atomic structure of glassy alloys.