Regensburg 2013 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MM: Fachverband Metall- und Materialphysik
MM 15: Poster Session
MM 15.54: Poster
Montag, 11. März 2013, 18:00–20:00, Poster E
Precipitate redissolution in Al-Cu-Li- alloy AA 2195 — •Judith Leese1, Kathrin Kolotzek1, Melanie Markgraf2, and Ferdinand Haider1 — 1Universität Augsburg, 86159 Augsburg — 2Premium Aerotec GmbH
A decrease in density of about 3 wt% for every wt% of Lithium combined with an increase in Youngs modulus of 6 % [1] made the straight path to many applications in aeronautics for Al-Cu-Li alloys. The alloy AA 2195 keeps its superior mechanical properties even at cryogenic temperatures [2]. The strength of this age hardenable Al-Cu-Li alloys is mainly controlled by volume fraction and size of the hardening precipitates like Θ', δ' and T1. Different processes during processing in industry can influence the microstructure of the peak-aged alloy via an short term heat input. The decrease in strength can be assigned to growth and dissolution reactions of the strengthing precipitates. The current study aims to resolve the microstructural processes during heat input for the commercial aluminum alloy AA 2195 at three different temperatures (250°C, 350°C and 510°C). The heating periods were varied from a few seconds to two hours. Vickers hardness measurements characterize the strength of the alloy. DSC measurements allows to monitor further kinetic reactions and TEM was used to record the correspondent changes in microstructure like size and distribution of the relevant precipitates. The combination of the different techniques prooves several reactions like dissolution and Ostwald Ripening during heating. [1] Material Science and Engineering,1980,44(2),213 [2] Journal of Materials Engineering and Performance,1998,7(5),682