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Indexed by:期刊论文

Date of Publication:2014-01-25

Journal:JOURNAL OF ALLOYS AND COMPOUNDS

Included Journals:SCIE、EI

Volume:584

Page Number:507-513

ISSN No.:0925-8388

Key Words:Alloys; Precipitation; Microstructure; Intermetallic compounds

Abstract:The thermal stability of Al-32Mg and Al-42Mg alloys prepared by solidification under high pressures, which contain a large amount of Al(Mg) solid solution, was investigated in the present paper. With increasing Mg content in the Al(Mg) solid solution, the mechanism of phase transformation has a remarkable difference compared to that prepared by other techniques. The GP zones first dissolve, then the gamma phase is formed; the stable beta phase is finally formed during the heating of Al(Mg) solid solution. By comparing formation of the precipitation phase of Al(Mg) solid solution prepared by different methods, it can be concluded that vacancy concentration may determine whether the beta' phase is formed, and whether the high Mg content is the necessary condition for the formation of gamma phase. The gamma phases that are precipitated from the Al(Mg) solid solution and formed during the solidification process all transform to the b phase in the Al-32Mg alloy; however, a part of the gamma phase stably exists in the Al-42Mg alloy according to the equilibrium phase diagram. (C) 2013 Elsevier B.V. All rights reserved.