Formation and thermal stability of Cu-Zr-Al-Er bulk metallic glasses with high glass-forming ability

The formation and thermal stabilities of Cu_46.25Zr_46.25-xAl_7.5Er_x, (x=0 to 8) bulk metallic glasses (BMGs) were investigated. The addition of a small amount of Er (2at%) for replacing Zr effectively improves the glass-forming ability of Cu_46.25Zr_46.25Al_7.5 alloy, and the glassy rod with a diameter of at least 12 mm can be formed. The glass transition temperature (T_g), temperature interval of supercooled liquid region ΔT_x (= T_x ? T_g, and reduced glass transition temperature T_rg (=T_g/T₁) of Cu_46.25Zr_44.25Al_7.5Er₂ glassy alloy are 699 K, 62 K and 0.607, respectively.