Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
11263585 | Materials Science and Engineering: A | 2018 | 26 Pages |
Abstract
The effect of tensile strain ranging from 1% to 7% on the decomposition sequence and mechanical properties of an AA2519 alloy with low Si content is studied. Pre-straining promotes the precipitation of θâ²- and Ω-phases at dislocations and suppresses the precipitation of GP-zones and θâ³-phase. The aspect ratio (AR) of the homogeneously nucleated ΩÎ-phase is higher than that of the ΩÎÎ-phase nucleated on the θâ²-phase/Al interfaces by a factor of ~â¯4. Replacement of θâ³-phase by a dispersion of θâ²- and Ω-phases took place under peak-ageing condition and thus imparted only a minor hardening effect, despite a seven-fold increase in the volume fraction of the strengthening precipitates. An increase in the yield stress by 30% with increasing pre-strain from 1% to 7% is attributed to an increase in the lattice dislocation density. Over-ageing leads to replacement of the ΩÎÎ-phase by the θâ²-phase.
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Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
Ivan Zuiko, Rustam Kaibyshev,