Crystal–quasicrystal transition depending on cooling rates in directionally solidified Al–3Mn–7Be (at.%) alloy

Abstract

The transition of primary phases from the crystalline approximant phase to icosahedral quasicrystal phase (I-phase) is observed in the directional solidified Al–3Mn–7Be (at.%) alloy. The structures of I-phase and approximant phases are characterized by SEM, TEM and HRTEM. The addition of Be significantly enhances the formation ability of I-phase, combining with the directional solidification method where the growth rates and temperature gradients can be separately controlled, giving rise to a promising way to prepare quasicrystal-reinforced Al-matrix composite.