Although the existence of star-shaped clusters of FeAl3 in aluminium alloys has been well known for a long time, it has not been possible to establish their origin. In this paper, experimental evidence is presented which suggests a correlation between these clusters and the basic growth mechanisms of monoclinic FeAl3. Ten-point stars have been observed in aluminium–iron alloys prepared by rapid cooling. These stars are shown to be compatible with the twinning mechanisms which have been observed during the growth of FeAl3. In particular, a multiple twinning mechanism is suggested to explain the existence of ten-point stars in aluminium-iron alloys.
