Glass forming ability and in-situ composite formation in Pd-based bulk metallic glasses

Pd60-xNi10Cu30Px alloys with x=10-20 were prepared by chill-casting, Bridgman solidification and melt spinning, giving a cooling rate range from 0.63 to similar to10(6) K/s. The effects of P content on the glass forming ability and in-situ bulk metallic glass (BMG) matrix composite formation in these alloys have been studied. Glass forming ability of the Pd-Ni-Cu-P alloys improves with increasing P content. This is interpreted in terms of the reduced glass transition temperature T-rg given by T-g/T-L and the crystallization rate constant K-T. F.c.c alpha-Pd crystalline phase reinforced BMG matrix composites have been synthesized in a wide range of compositions. The formation of the in-situ BMG matrix composite is explained qualitatively in terms of competition between eutectic growth and amorphous phase formation. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.