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 peritecfic 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.