Microstructure of Small Amount of TM Added Al-Mg-Si Alloys with Two-Step Ageing

Traditionally, Al-Mg-Si alloys are strengthened by dispersed small particles and they have medium strength with good formability. It is well known that alloying elements on Al-Mg-Si alloys (e.g. Cu) can improve mechanical properties because Cu can alter precipitation sequence. In this research, we investigated the effect of transition metals (TM) on Al-1.06at.%MgSi-TM alloys through single- and two-step ageing. Mechanical property and microstructure observation were conducted by micro Vickers hardness measurement and transmission electron microscopy.