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.

Acknowledgements

The authors would like to thank Prof. S. Ranganathan, Prof. D. H. Kim and Prof. B. S. Murty for many stimulating discussions. The financial support from the Ministry of Non-Conventional Energy Sources (MNES) and UNANST (DST) New Delhi, India is gratefully acknowledged. The author (T. P. Y) acknowledges the support of CSIR for award of Senior Research Fellowship.