Melting Point Measurements for Quasicrystalline Phases

Abstract

AbstractMelting transitions of metastable quasicrystalline phases of Al-Mn have been observed using rapid electron-beam heating of fine-grained icosahedral surface layers. The congruent melting-point for icosahedral Al80 Mn20 was directly measured to be 910±20°C. Heating to higher temperatures shows another transition which is inferred to correspond to the liquidus of the decagonal phase at 965±20°C for 20 at.% Mn. The microstructure and formation kinetics of the decagonal phase are discussed, and its electron diffraction is described.