Development of quasicrystal morphology in gas-atomized icosahedral-phase-strengthened aluminum alloy powders

Abstract The microstructures in gas-atomized powders and in blind-die-compacted material from three Al-Cr-Mn-Co-Zr alloys has been studied using a X-ray diffraction and electron microscopy. The materials consist of a mixture of FCC Al and icosahedral quasicrystalline phases, but three different phase distributions are observed which depend on the powder particle size, and hence on the cooling rate. The finest particles contain a nanocomposite mixture of equiaxed Al grains and fine (