The role of disclinations in two phase changes induced by temperature and pressure in crystalline solids: melting and the brittle-ductile transition

Authors: D.J. Klein¹; N.H. March²

Source: Physics and Chemistry of Liquids, Volume 42, Number 5, October 2004 , pp. 545-550(6)

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Abstract:

It has long been known that the melting temperature T_m of close-packed metals correlates well with the mono-vacancy formation energy. However, with the possible exception of the face-centered-cubic metals, there is a prior phase transition from a mechanically brittle solid phase to a ductile phase. Here the likely role of disclinations in the brittle-ductile phase change is stressed. The present picture may help to understand the brittle-ductile transition not only in crystalline materials but also in amorphous phases. The structure of such phases can probably be characterized in terms of a disordered disclination network. As examples of elemental crystalline solids, Si and graphite are finally discussed, with the melting under pressure of graphite being quantified.

Keywords: Disclinations; Brittle-ductile transition; Melting

Document Type: Research article

DOI: http://dx.doi.org/10.1080/003191004123312732415

Affiliations: 1: Texas A&M University at Galveston Galveston Texas 77551 USA 2: Physics Department University of Antwerp Antwerp Belgium and Oxford University Oxford England

Publication date: 2004-10-01