Abstract: A group of Cu(Zr)-based bulk metallic glasses (BMGs) with critical diameter (Dc) in the 12 to 18 mm range have been obtained using copper mould casting. In the Cu-Zr-Y-Al quaternary system, a new record of Dc=14 mm was established for Cu-based compositions, and 16 mm for compositions based on equi-atomic CuZr. Additional partial substitution of Hf for Zr further elevated the Dc to 18 mm at Cu42Zr43Hf1.5Y3.5Al10.

Key words: Bulk metallic glasses, Glass-forming ability, Copper, Zirconium