Formation of quasicrystalline phases in an Al–Cu–Co–Fe alloy obtained by using a gravity chill-casting technique

Abstract

A study of the quasicrystalline phases obtained from a quaternary alloy of Al–Cu–Co–Fe is carried out. The formation of these phases is based on a gravity chill-casting technique. The alloy was cast in a wedge-shaped copper mold. Optical and scanning electron micrographs show a characteristic dendritic growing in regions close to the wedge edge. These types of dendrites display apparent symmetries that resemble the tenfold, fivefold, and eightfold symmetries obtained in quasicrystalline materials. Electron diffraction patterns, in addition to x-ray diffraction patterns, show two kinds of quasicrystalline phases. The icosahedral and decagonal phases coexist in these types of alloys also with binary and ternary compounds of intermetallic nature.