Preparation of Bulk Glassy Pd<SUB>40</SUB>Ni<SUB>10</SUB>Cu<SUB>30</SUB>P<SUB>20</SUB> Alloy of 40 mm in Diameter by Water Quenching

Abstract

Cylindrical glassy alloys with diameters up to 40 mm were prepared for a Pd40Ni10Cu30P20 alloy with a high reduced glass transition temperature (Tg⁄Tm) of 0.71 by water quenching the molten alloy in the quartz tube. The bulk glassy alloy with a diameter of 40 mm exhibits good metallic luster on the outer surface. Neither cavities nor voids are seen over the whole inner region and no contrast revealing a crystalline phase is seen over the transverse cross section. The glass transition temperature (Tg), crystallization temperature (Tx), the temperature interval of the supercooled liquid region (ΔTx=Tx−Tg) and the melting temperature (Tm) are measured to be 575, 95 and 804 K, respectively, for the Pd40Ni10Cu30P20 alloy with a diameter of 40 mm. The deviation of Cu content from 30 at%Cu in the Pd40Ni40−xCuxP20 system causes a steep increase in Tm and a decrease in Tg⁄Tm, leading to the decrease in the glass-forming ability. The successes of finding the new Pd–Cu base alloy composition with the large ΔTx and Tg⁄Tm values and preparing the bulk glassy alloy with a diameter of 40 mm are encouraging for the future development of glassy alloys.