Quantitative HAADF STEM study of β'-like precipitates in an Al-Mg-Ge alloy

Abstract

Precipitates in an Al-Mg-Ge alloy similar to the β' phase in Al-Mg-Si alloys were investigated using quantitative aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF STEM). Quantitative investigation into the Ge-rich columns of the precipitates found the intensity of these columns to be consistent with an Al concentration of 30±10 %, or a vacancy concentration of 20±10 %. Possible errors involved in the determination of the column composition are discussed.