Thermal properties of Hf-based metallic glasses

Recently new Hf-based multicomponent amorphous alloys have been developed based on empirical rules for large glass forming ability. These ribbons were obtained by melt–spinning a master alloy, composed of Group IVB elements (Ti, Zr, Hf) of the Periodic Table with additions of late transition metals such as Cu or Ni. One of the best known bulk glass-forming alloy systems is based on (Zr/Ti)–(Cu/Ni)–Al, the addition of Al of the IIIA group with sp electrons and strong interactions with Zr is a key factor in reducing the critical cooling rate for glass formation. Hf is chemically similar to Zr but has a much higher melting temperature. Characterization of the as-quenched (Hf/Zr/Ti)–(Cu/Ni)–(Al/Ga)–(Si/Ge) ribbons was carried out by X-ray diffraction and the thermal stability was followed by differential scanning calorimetry and differential thermal analysis.