Studies on Al–Ni–Fe decagonal quasicrystalline alloy prepared by mechanical alloying

Abstract

Decagonal quasicrystalline Al70Ni24Fe6 powder was produced by mechanical alloying of the elemental powders followed by annealing. A high-purity elemental powder mixture of 70 at.% Al, 24 at.% Ni and 6 at.% Fe was mechanically milled for various times up to 100 h and annealed at 750°C for 40 h. The powders milled for 100 h upon annealing showed formation of 200–300 nm size decagonal phase grains as the major component along with minor amounts of Al3Ni2 (τ3) and B2-type phases. The formation of decagonal phase and related crystalline phases was confirmed using the X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray microanalysis techniques. It is interesting to note that the decagonal phase did not form directly after milling. Subsequent annealing is required for the formation of decagonal quasicrystalline phase.