A different dependence of apparent glass-forming ability (GFA) on casting-atmosphere pressure is observed in a Zr65 Al7.5 Ni10 Cu17.5-x Pdx (x=0-17.5) alloy system. Low-Pd alloys (x<12.5) reveal low GFA dependence, while high-Pd ones (x12.5) show high GFA dependence on atmosphere pressure applied during casting. The phenomenon is suggested to originate from the fact that for the high-Pd alloys, the transformation region of supercooled-liquid to quasicrystalline phase is located at the lowerature side of the undercooled-liquid region where the atmosphere-pressure dependence of cooling characteristic coincidently takes place. The on-cooling phase transformation in the alloy system and the cooling mechanism during mold-casting process are discussed comprehensively.
ASJC Scopus subject areas
- Physics and Astronomy(all)