Undercooling behavior and critical cooling rate of Pd-Pt-Cu-P alloy

Abstract

In order to realize biomedical applications of bulk glassy alloys, we have developed new Pd-based glassy alloys with Ni-free composition in Pd-Pt-Cu-P system and it is revealed that the highest glass-forming ability is obtained at a composition of Pd35Pt15Cu30P20. In addition, the alloy can be formed into bulk glassy rods with diameters of up to at least 30 mm by fluxed water quenching. In order to clarify the critical cooling rate for glass-formation, undercooling behavior and crystal growth rate are also discussed. Crystallization of the alloy under continuous cooling is mainly dominated by surface nucleation. Apparent crystal growth rate of the alloy at 0.73 Tm is evaluated to be 5.2 × 10-6 m.s-1 and this value is four orders of magnitude higher than that of previous Pd40Cu30Ni10P20 at the same degree of undercooling. © 2005 The Japan Institute of Metals.