Nano-scale icosahedral quasicrystals crystallized from Zr-Nb-Ni-Cu-Al metallic glasses

Abstract

Precipitation of nano-scale icosahedral quasicrystals occurs upon completion of the first exothermic reaction on continuously heating in Nb containing Zr-based metallic glasses. Nb is the decisive component favoring the precipitation of quasicrystals. Their melting points were measured. The glass-forming ability (GAF) was estimated from the reduced temperature Tg/Tm (Tg is the glass transition temperature, Tm the melting point) and supercooled liquid region. Experimental results show that the quasicrystal-forming alloy can be cast into cylinders of 4 mm in diameter by copper mold casting in vacuum being fully glassy.