A senary TiZrHfCuNiBe high entropy bulk metallic glass with large glass-forming ability

Most reported bulk metallic glasses (BMGs) contain multiple constituent elements but only one of them is the principal element. Here we report that a senary Ti16.7Zr16.7Hf16.7Cu16.7Ni16.7Be16.7 high entropy bulk metallic glass (HE-BMG) with a critical diameter larger than 15 mm has been successfully prepared by copper mold casting. It shows that newly developed HE-BMG possesses large glass-forming ability, together with the supercooled liquid region Delta T (=T-x-T-g), reduced glass transition temperature T-rg (=T-g/T-1) and gamma parameter (=T-x/(T-g-T-1)) of 70 K, 0.619 and 0.422, respectively. The present result indicates that high entropy alloys, even for senary alloys or metal-metal type, could also possess large glass-forming ability. And the present HE-BMG could serve as a model material for studying the fundamental issues both of high entropy alloys and bulk metallic glasses. (C) 2014 Elsevier B.V. All rights reserved.