Formation and Mechanical Properties of Zr-Nb-Cu-Ni-Al-Lu Bulk Glassy Alloys with Superior Glass-Forming Ability

Glass-forming ability (GFA) and mechanical properties of (Zr0.58Nb0.03Cu0.16Ni0.13Al0.10)100-x Lu x (x = 0-3 at%) alloys have been investigated. The GFA of Zr58Nb3Cu16Ni13Al10 alloy is dramatically enhanced by adding Lu. The (Zr0.58Nb0.03Cu0.16Ni0.13Al0.10)98Lu2 alloy possesses the highest GFA in the studied Zr-Nb-Cu-Ni-Al-Lu alloys, with its critical diameter for glass formation reaching 20 mm by copper-mould casting method, while that of the Lu-free Zr58Nb3Cu16Ni13Al10 alloy is 7 mm. The critical diameters of (Zr0.58Nb0.03Cu0.16Ni0.13Al0.10)100-xLux (x = 1 at% and 3 at%) alloys are 15 mm and 12 mm, respectively. The Lu addition to Zr58Nb3Cu16Ni13Al10 alloy induces the change of initial crystallization phases from face-centred-cubic Zr2Ni and tetragonal Zr2Ni phases for the Lu-free Zr58Nb3Cu16Ni13Al10 alloy to an icosahedral quasi-crystalline phase for the Lu-doped alloys, which may be the origin for the enhanced GFA of the Lu-doped alloys. The compressive fracture strength and plastic strain of the bulk glassy (Zr0.58Nb0.03Cu0.16Ni0.13Al0.10)98Lu2 alloy are 1 610 MPa and 1.5%, respectively.