Effect of composition on the formability of quasicrystalline phase in mechanically alloyed Al-Cu-Fe powders

摘要

A systematic study has been carried out to investigate the effect of composition on the ability of mechanically alloyed Al-Cu-Fe powders to form quasicrystalline (QC)-phases. Their microstructures were measured by means of X-ray diffraction and transmission electron microscopy (TEM). The results show that the formation of Al-Cu-Fe QC-phases is sensitive to the starting ratio of the elements Al, Cu and Fe and that Al_(70)Cu_(20)Fe_(10) is the optimum composition among those studied. No single QC-phase was obtained, but a high volume fraction of the QC-phase can be obtained by a suitable choice of the milling time, annealing temperature and annealing time. The volume fraction of the QC-phase in Al_(70)Cu_(20)Fe_(10) powders milled for 2 h and annealed for 5 h at 750 ℃ is greater than 90%.