The formation of precipitate plates and their role in the strengthening of aluminium alloys

J. F. Nie, H. I. Aaronson, B. C. Muddle

Research output: Chapter in Book/Report/Conference proceedingConference PaperOther

1 Citation (Scopus)

Abstract

Rationally-oriented, plate-shaped precipitates of transition phases are often key strengthening constituents in high strength and ultra-high strength aluminium alloys. These precipitate phases include {100}α plates of θ′ (Al2Cu) and {111}α plates of Ω (Al2Cu) and T1 (Al2CuLi). The identity and distribution of these precipitate phases are often controlled by pre-precipitate clusters of microalloying elements. It is demonstrated that the transformation strain defining the change in structure associated with formation of such precipitate phases involves a large shear component and that the manner in which the shear strain energy is accommodated is a critical factor in controlling the formation of the precipitate plates. One way in which this shear strain energy might be minimised during nucleation is if the nucleus forms in association with rationally-oriented clusters combining relatively large solute atoms with a local excess of vacancies. For a given volume fraction and number density of precipitate plates which are either shearable or shear-resistant, plate-shaped precipitates formed on {111}α planes of the aluminium-rich matrix solid solution are most effective in strengthening, and the yield strength increment produced by {111}α precipitate plates increases with increasing plate aspect ratio.

Original languageEnglish
Title of host publicationAdvances in the Metallurgy of Aluminum Alloys
EditorsM. Tiyakioglu, M. Tiyakioglu
Pages229-238
Number of pages10
Publication statusPublished - 1 Dec 2001
EventProceedings from Materials Solutions Conference 2001 - Indianapolis, United States of America
Duration: 5 Nov 20018 Nov 2001

Publication series

NameAdvances in the Metallurgy of Aluminum Alloys

Conference

ConferenceProceedings from Materials Solutions Conference 2001
CountryUnited States of America
CityIndianapolis
Period5/11/018/11/01

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