Nanoquasicrystallization of Zr-based metallic glasses

Nanoquasicrystallization occurs in a number of Zr based metallic glasses. This paper reviews the influence of various elements on the icosahedral phase formation in Zr-based metallic glasses in order to understand the necessary conditions for nanoquasicrystallization. Icosahedral phase is stabilized in Zr65−xCu27.5Al7.5Ox alloys beyond a critical oxygen level, suggesting that oxygen is a factor to stabilize icosahedral phase formation in Zr–Cu(–Ni)–Al based metallic glasses. On the other hand, Zr-based alloys containing Pd do not require oxygen for icosahedral phase formation. In the presence of Pd, even binary Zr100−xPdx (x=30 and 35) alloys show nanoquasicrystallizaiton in the course of amorphous to crystal transformation. Based on our recent results together with other published investigations, the necessary conditions for quasicrystallization are discussed.