Stability of quasicrystalline phase in Al–Cu–Fe, Al–Cu–Co and Al–Pd–Mn systems by high energy ball milling

Abstract The stability of the quasicrystalline phase present in as-cast Al 65 Cu 20 Fe 15 , Al 65 Cu 20 Co 15 and Al 72 Pd 19.5 Mn 8.5 alloys during high energy ball milling and on subsequent annealing has been studied. The synthesis and stability of the quasicrystalline phase prepared by mechanical alloying of Al 65 Cu 20 Fe 15 , Al 70 Cu 20 Fe 10 and Al 65 Cu 20 Co 15 alloys has also been studied. In all the cases, the quasicrystalline phase is unstable with long hours of milling and transforms to the β-phase (bcc phase), which is stable on further milling and on subsequent annealing up to 1073 K. The quasicrystalline to β-phase transformation appears to occur for grain sizes below 20 nm.