Formation and thermal stability of Pd-based bulk metallic glasses

Abstract

The glass-forming ability and thermal stability of bulk glassy Pd79Cu6Si10P5 alloy were studied by substitution of Cu with Ag and with Au+Ag from 0 to 6at.%. The results indicated that the small addition of Ag strongly affects the thermal stability and glass-forming ability of the Pd79Cu6Si10P5 alloy. The alloy doped with 4at.% Ag (Pd79Cu2Ag4Si10P5) exhibits the largest glass-forming ability among the Pd79Cu6−xAgxSi10P5 (x=0–6at.%) alloys. The critical diameter for glass formation of this alloy reaches as large as 7mm by copper mold casting. On the other hand, the multi-addition of Au+Ag does not increase the glass forming ability though the Ag and Au are similar in atomic size. The largest glass forming ability is obtained at 1at.% Au+2at.% Ag among the Pd79Cu6−x−yAuxAgySi10P5 (x=1–4at.%, y=1–3at.%) alloys. The critical diameter of this alloy is 5mm by copper mold casting.