Details

Autor(en) / Beteiligte

• Koshino, Yuki
• Kozuka, Masaya
• Hirosawa, Shoichi
• Aruga, Yasuhiro

Titel

Comparative and complementary characterization of precipitate microstructures in Al–Mg–Si(–Li) alloys by transmission electron microscopy, energy dispersive X-ray spectroscopy and atom probe tomography

Ist Teil von

• Journal of alloys and compounds, 2015-02, Vol.622, p.765-770

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2015

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• •Microalloying addition of Li enhances the age-hardening response of Al–Mg–Si alloys.•Size and number density of nanoclusters or precipitates are increased by Li addition.•Mg and Si contents within the aggregates are inversely decreased by Li addition.•Microalloying Li accelerates heterogeneous nucleation of such Mg–Si aggregates. In this study, comparative and complementary characterization of precipitate microstructures by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS) and atom probe tomography (APT) has been performed for Al–0.55wt%Mg–0.89wt%Si(–0.043wt%Li) alloys aged at 433K for 1.2ks (under aging) and 36ks (peak aging). Quantitative estimation of nanometer-scale clusters (nanoclusters) and β″ precipitates by TEM and APT revealed that microalloying addition of Li increases the size and number density of these Mg–Si aggregates, resulting in the enhanced age-hardening response. Positive evidence by APT for the segregation of Li suggests that heterogeneous nucleation of such Mg–Si aggregates with the aid of Li is attributed to the modified precipitate microstructures and thus improved mechanical strength of this alloy system.