EFTEM observation for nano-scaled precipitates in aluminum alloys

Application of energy filtered transmission electron microscopy (EFTEM) to nano-scaled precipitates in aluminum alloys were investigated to know their chemical compositions. Its resolution, which can confirm the existence of elements, were also reported and compared with theoretical ones. In Al-15 mass% Ag and Al-4.0 mass% Cu Al-Cu alloy, G.P. zones in both alloys were observed and confirmed G.P. zones larger than 3.4 and 1.6 nm, respectively. We have also applied this technique for the β 'phase in Al-1.0 mass% Mg₂Si alloy and the GPB zone in Al-4.3 mass% Cu-1.8 mass% Mg alloy. It finds that it can be observed elemental maps when the β ' phase in Al-Mg-Si alloy is larger than 4.7 nm (Mg-map) and 4.2 nm (Si-map). In the case of GPB zone in Al-Cu-Mg alloy, it can be observed larger than 2.1 nm (for both of Cu and Mg-map).