An Attempt to Prepare Metallic Glasses from Quasicrystals

Icosahedrons in supercooled liquids and glasses are considered to be of significance for the glass formation in alloy systems. Starting from the similarity of the local structure of quasicrystals to the icosahedrons in metallic glasses, a scheme is put forward to prepare metallic glasses based on a well-known quasicrystal Zr_40Ti_40Ni_20. A series of (Zr_40Ti_40Ni_20)_100-xCo_x metallic glasses are fabricated, and the optimized glass forming composition is determined at (Zr_40Ti_40Ni_20)_92Co_8. The results show that the glass-forming ability of the alloys is closely related to the quasicrystalline phases. The mechanism of the enhanced glass-forming ability is discussed.