Structure, phase composition, and strengthening of cast Al–Ca–Mg–Sc alloys

Abstract

The structure and phase composition of Al–Ca–Mg–Sc alloys containing 0.3 wt % Sc, up to 10 wt % Ca, and up to 10 wt % Mg have been investigated in the cast state and state after heat treatment. It has been shown that only binary phases Al₄Ca, Al₃Sc, and Al₃Mg₂ can be in equilibrium with the aluminum solid solution. It has been found that the maximum strengthening effect caused by the precipitation of Al₃Sc nanoparticles for all investigated alloys is attained after annealing at 300–350°C.