The compositions of metastable phase precipitates observed at peak hardne condition in an Al-Mg-Si alloy

摘要

The metastable-phase precipitates which appear at the peak condition of hardnes Al-0.83 at% Mg-0.4 at %Si alloy were investigated, using a combination of Vickers microhardn DSC calorimetry, and field-emission STEM observations with EDX analyses. EDX and elemental revealed that both Si-rich and Mg-Si precipitates with needle-shapes were present. EDX analysi that needle-shaped β"precipitates protruding from the specimen foils were composed mainly present results on structures, compositions and thermal stabilities of the precipitates suggest th precipitates co-exist with complex Mg-Si precipitates also of needle-shape.