TEM Observation of Cu and Ag Added Al-Mg-Si Alloy

It is well known that Cu and Ag addition on Al-Mg₂Si alloy can enhance its mechanical properties due to solid solution hardening. Several reports are available about the effect of each alloying elements, Cu and Ag, on Al-Mg-Si alloys. In this research, Al-Mg-Si-Cu-Ag alloys have chemical compositions of (1) 0.18Cu-0.18Ag and (2) 0.35Cu-0.35Ag [at.%] fixed Cu/Ag rate of 1.0 are prepared using casting to estimate effects of Cu and Ag amount to precipitation behaviour and mechanical properties. The Vickers microhardness measurement was conducted to estimate mechanical property after ageing treatment microstructure observation was carried out using transmission electron microscopy. In peak-aged at 473 K hardness of each alloys was almost the same, but in peak-aged at 523 K, hardness of 0.35Cu-0.35Ag was higher than 0.18Cu-0.18Ag alloy.