Fabrication of New Cu₃₄Pd₂Zr₄₈Ag₈Al₈ Bulk Glassy Alloy with a Diameter of 30 mm

Abstract

Glass-forming ability (GFA) of Cu_36−xPd_xZr₄₈Ag₈Al₈ alloys was examined with the aim of developing a bulk glassy alloy with large critical diameter. It was found that the addition of 2 at% Pd significantly improved the GFA of the Cu₃₆Zr₄₈Ag₈Al₈ alloy. The fully glassy alloy rod with a diameter of 30 mm was successfully fabricated for the Cu₃₄Pd₂Zr₄₈Ag₈Al₈ alloy using a copper mold casting method. The further increase of Pd content causes the decrease in the GFA. For the Cu_36−xPd_xZr₄₈Ag₈Al₈ alloys, the T_g and T_x increase monotonously with increasing Pd content, while T_l shows a minimum value at 2 at% Pd, resulting in a maximum γ (=T_x⁄(T_g+T_l)) value at 2 at% Pd. The increase of γ parameter may be the reason for the significant improvement of the GFA of the quinary alloy.