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Highly processable bulk metallic glass-forming alloys in the Pt–Co–Ni–Cu–P system

Schroers, Jan and Johnson, William L. (2004) Highly processable bulk metallic glass-forming alloys in the Pt–Co–Ni–Cu–P system. Applied Physics Letters, 84 (18). pp. 3666-3668. ISSN 0003-6951. http://resolver.caltech.edu/CaltechAUTHORS:SCHRapl04

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Abstract

Highly processable bulk metallic glass alloys in the Pt–Co–Ni–Cu–P system were discovered. The alloys show low liquidus temperature below 900 K, excellent processability with low critical cooling rate reflecting in maximum casting thicknesses in quartz tubes of up to 20 mm, and a large supercooled liquid region. The Pt57.5Cu14.7Ni5.3P22.5 composition has a liquidus temperature of 795 K, a glass transition temperature of 508 K with a supercooled liquid region of 98 K. For medical and jewelry applications a Ni-free alloy, Pt60Cu16Co2P22 was discovered with a liquidus temperature of 881 K, a glass transition temperature of 506 K, and a supercooled liquid region of 63 K. Glass formation was observed in a wider composition range. Vickers hardness of these alloys is in the 400 Hv range. The alloys can be processed in the supercooled liquid region in air without any measurable oxidation. In this region, a large processing window is available in which the material does not embrittle. Embrittlement in these alloys is correlated with crystallization. It can be avoided as long as substantial crystallization does not take place during isothermal processing in the supercooled liquid region. Also, liquid processing can be performed in air when flux with B2O3.


Item Type:Article
Additional Information:©2004 American Institute of Physics. Received 10 December 2003; accepted 12 March 2004; published online 20 April 2004.
Subject Keywords:platinum alloys; metallic glasses; cobalt alloys; nickel alloys; copper alloys; phosphorus alloys; casting; supercooling; crystallisation; vitrification; glass transition; Vickers hardness; embrittlement
Record Number:CaltechAUTHORS:SCHRapl04
Persistent URL:http://resolver.caltech.edu/CaltechAUTHORS:SCHRapl04
Alternative URL:http://dx.doi.org/10.1063/1.1738945
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:4158
Collection:CaltechAUTHORS
Deposited By: Tony Diaz
Deposited On:06 Aug 2006
Last Modified:26 Dec 2012 08:58

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