Effect of Zr on the crystallization behavior of multi-component Zr-based metallic glasses

Melt-spun Zr-y(Ti0.186Nbu.058CU0.324Ni0.258Al0.174)(100-y) glassy ribbons with y=57 and 62 were investigated by differential scanning calorimetry, X-ray diffraction and transmission electron microscopy in order to clarify the role of Zr on the crystallization behavior. The devitrification of the ribbons is characterized by the formation of a metastable icosahedral quasicrystalline phase during the first stage of the crystallization process. With increasing amount of Zr the thermal stability against crystallization decreases whereas the temperature range of stability of the quasicrystalline phase increases. Furthermore, the grain size and the volume fraction of the quasicrystalline precipitates increases with increasing Zr content. Accordingly, appropriately adjusting the Zr content allows for tuning the thermal stability as well as the microstructure evolution upon heating. (C) 2006 Elsevier B.V. All rights reserved.