Microstructure and strengthening of Al-Li-Cu-Mg alloys and MMCs: I. Analysis and modeling of microstructural changes[Metal Matrix Composites]
A complete and detailed analysis of the microstructural development during ageing in an 8090 (Al-2.3Li-1.2Cu-1Mg-0.1Zr) alloy, an 8090/20 wt% SiC{sub p} MMC, an Al-1.5Li-Cu-Mg MMC and an Al-Cu-Mg MMC (all with similar Cu and Mg contents) has been performed. Volume fractions of all precipitates relevant for precipitation strengthening of the alloys ({delta}{prime} phase, S{prime} phase and GPB zones) have been determined using a recently derived method based on differential scanning calorimetry (DSC). The volume fractions have subsequently been successfully fitted using a novel model for transformation kinetics. The sizes of these precipitates have been analyzed using newly derived expressions consistent with the latter model. As a result of dislocation generation around misfitting SiC particles the volume fractions of both GPB zones and S{prime} phase depend strongly on the presence of these particles. Also the amount of Li present in the alloys influences the volume fractions of the phases significantly. The sizes of S{prime} are similar for the four alloys.
- Research Organization:
- Univ. of Southampton (GB)
- OSTI ID:
- 20002026
- Journal Information:
- Acta Materialia, Journal Name: Acta Materialia Journal Issue: 14 Vol. 47; ISSN ACMAFD
- Country of Publication:
- United States
- Language:
- English
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