Fabrication of Cu–Zr–Ag–Al glassy alloy samples with a diameter of 20 mm by water quenching

The melting behavior, thermal stability, and glass-forming ability (GFA) of Cu_84−xZr_xAg₈Al₈ (x = 42 to 50) glassy alloys were investigated. The alloy with x = 46 exhibits the highest reduced glass transition temperature (T_rg). However, the best GFA was obtained for alloy with x = 48 corresponding to the largest supercooled liquid region (ΔT_x) and a deep eutectic composition. At the best GFA composition, full glassy samples with diameters of over 20 mm could be fabricated by injection copper mold casting and water quenching without flux. The underlying mechanism of the unusual GFA of the alloy is discussed.