Influence of a supercooled liquid on devitrification of Cu-, Hf- and Ni- based metallic glasses

The purpose of the present work is to study and compare devitrification behaviour of some Cu-, Ni- and Hf-based rapidly solidified metallic glasses in relation with supercooled liquid region. Devitrification on heating process was investigated using differential scanning and isothermal calorimetry. The structure was examined by X-ray diffraction and transmission electron microscopy (TEM). The studied alloys exhibit a multistage devitrification. A large difference in devitrification behaviour was observed between the studied metallic glasses. The alloys which exhibit the supercooled liquid region, form metastable nanoscale cubic phases. Devitrification behaviour of the studied alloys is compared with that of Ti-, Zr- and Hf-based metallic glasses studied elsewhere.