MICROSTRUCURE AND STRENGTHENING OF Al-Li-Cu-Mg ALLOYS
نویسندگان
چکیده
A detailed quantitative model for the strengthening of monolithic alloys and composites due to precipitation strengthening, solution strengthening, grain and subgrain strengthening, strengthening by dislocations and load transfer to ceramic inclusions is presented. The model includes a newly derived description of the effect of a precipitate free zone (PFZ) around the reinforcing phase incorporating strain hardening of the PFZ. The model is successfully applied to model the experimental data for the proof strengths of four Al-Li-Cu-Mg type alloys and composites aged to obtain a wide range of microstructures and all strengthening contributions are quantified. It is shown that PFZ formation in the 8090 MMC causes a drastic reduction in the proof strength (about 100 MPa), but it has little influence on the time required for peak ageing. In all alloys strengthening due to GPB zones is more important than strengthening due to δ' (Al3Li) phase.
منابع مشابه
Microstrucure and Strengthening Of
A complete and detailed analysis of the microstructural development during ageing in an 8090 (Al-2.3Li-1.2Cu-1Mg-0.1Zr) alloy, an 8090/20wt%SiCp 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 (δ' phase, S' phase and GPB zones) have been determined...
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