Growth morphology and evolution of quasicrystal in as-solidified Y-rich Mg-Zn-Y ternary alloys

摘要

A petal-like icosahedral quasicrystal with five branches, which is considered to be the representative morphology of the icosahedral quasicrystal, has been observed in the Y-rich Mg-Zn-Y ternary alloys. Moreover, the polygon-like morphology, another pattern of the icosahedral quasicrystal, has also been found in the Y-rich Mg-Zn-Y ternary alloys. The latter morphology results from the evolution of the former one. The growth mechanism of the petal-like morphology of the icosahedral quasicrystal was also discussed. Alloying composition, i.e., Y element content, is a major factor inducing the morphology evolution of the icosahedral quasicrystal.