Single-crystal growth of the Al–Cu–Fe icosahedral quasicrystal from the ternary melt

An Al–Cu–Fe partial phase diagram involving the icosahedral quasicrystal has been constructed along an Al_62.5Cu_37.5−xFe_x (x = 2.5 to 25 at.%) isopleth. The icosahedral quasicrystal forms at 850 °C via a peritectic reaction between a liquid and (Al,Cu) ₁₃Fe₄ phase and coexists with a liquid phase at temperature below the peritectic reaction. The icosahedral quasicrystal crystallizes as a primary phase in the temperature range of 760 to 850 °C from alloys surrounded by composition points of Al–Cu–Fe: 62.5–33–4.5, 62.5–34.5–3, 57.5–39.5–3 and 57.5–38.0–4.5 at.%. On the basis of the phase diagram, single grains of the Al–Cu–Fe icosahedral quasicrystal with a maximum size of 5 mm were successfully grown from Al–Cu–Fe melts.