Relation between Local Structure and Glass Forming Ability of Liquid Alloys

Waseda, Y and Chen, HS and Jacob, KT and Shibata, H (2007) Relation between Local Structure and Glass Forming Ability of Liquid Alloys. In: High Temperature Materials and Processes, 26 (5-6). pp. 403-416.

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Abstract

An attempt has been made to describe the glass forming ability (GFA) of liquid alloys, using the concepts of the short range order (SRO) and middle range order (MRO) characterizing the liquid structure.A new approach to obtain good GFA of liquid alloys is based on the following four main factors: (1) formation of new SRO and competitive correlation with two or more kinds of SROs for crystallization, (2) stabilization of dense random packing by interaction between different types of SRO, (3) formation of stable cluster (SC) or middle range order (MRO) by harmonious coupling of SROs, and (4) difference between SRO characterizing the liquid structure and the near-neighbor environment in the corresponding equilibrium crystalline phases. The atomic volume mismatch estimated from the cube of the atomic radius was found to be a close relation with the minimum solute concentration for glass formation. This empirical guideline enables us to provide the optimum solute concentration for good GFA in some ternary alloys. Model structures, denoted by Bernal type and the Chemical Order type, were again tested in the novel description for the glass structure as a function of solute concentration. We illustrated the related energetics of the completion between crystal embryo and different types of SRO. Recent systematic measurements also provide that thermal diffusivity of alloys in the liquid state may be a good indicator of their GFA.

Item Type:	Journal Article
Publication:	High Temperature Materials and Processes
Publisher:	Walter de Gruyter GmbH & Co. KG
Additional Information:	Copyright of this article belongs to Walter de Gruyter GmbH & Co. KG.
Keywords:	Metallic glass;Short-range ordering;Middle-range ordering; Stable cluster;thermal diffusivity
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	29 Dec 2011 05:40
Last Modified:	29 Dec 2011 05:40
URI:	http://eprints.iisc.ac.in/id/eprint/42750

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