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 (Zr 0.58 Nb 0.03 Cu 0.16 Ni 0.13 Al 0.10 ) 100- x Lu x ( x = 0-3 at%) alloys have been investigated. The GFA of Zr 58 Nb 3 Cu 16 Ni 13 Al 10 alloy is dramatically enhanced by adding Lu. The (Zr 0.58 Nb 0.03 Cu 0.16 Ni 0.13 Al 0.10 ) 98 Lu 2 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 Zr 58 Nb 3 Cu 16 Ni 13 Al 10 alloy is 7 mm. The critical diameters of (Zr 0.58 Nb 0.03 Cu 0.16 Ni 0.13 Al 0.10 )100-xLux (x = 1 at% and 3 at%) alloys are 15 mm and 12 mm, respectively. The Lu addition to Zr 58 Nb 3 Cu 16 Ni 13 Al 10 alloy induces the change of initial crystallization phases from face-centred-cubic Zr 2 Ni and tetragonal Zr 2 Ni phases for the Lu-free Zr 58 Nb 3 Cu 16 Ni 13 Al 10 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 (Zr 0.58 Nb 0.03 Cu 0.16 Ni 0.13 Al 0.10 ) 98 Lu 2 alloy are 1 610 MPa and 1.5%, respectively.