Formation and Stability of Single-Phase Al-Cu-Fe Quasicyrstals under Pressure

摘要

Alloy powder with nominal composition Al₆₇Cu₂₃Fe₁₀ was prepared by ball-milling of elemental metallic powders. The as-milled powder consists mainly of a nanocrystalline Al(Cu,Fe) solid solution. The structural phase transitions upon heating under different pressures were investigated by in-situ X-ray diffraction at the F2.1 beamline of desy-hasylab (Hamburg, Germany), in order to establish a pressure-temperature phase diagram. A single-phase quasicrystalline powder was obtained upon heating above 800 °C, following a sequence of phase transitions at temperatures lower than 700 °C. The quasicrystalline phase was found to be stable upon quenching under pressure.