Formation and crystallization of CuZrHfTi bulk metallic glass under ambient andhigh pressures

Abstract

The formation of CuZrHfTi bulk metallic glasses (BMGs) and the crystallization of the typical Cu60Zr20Hf10Ti10BMG under ambient conditions and high pressure have been investigated bydifferential scanning calorimetry, x-ray diffraction (XRD) and in situ synchrotronradiation XRD. The effects of high pressure on crystallization and formation ofthe CuZrHfTi alloy are discussed. The Kauzmann temperature, TK,where the entropy of the undercooled liquid equals that ofthe crystal, is also determined to be 724 K. The TK iscompared with the experimentally observed rate-dependent glass transition, Tg.The kinetic study of the crystallization shows that the Cu-based BMG has muchlarger activation energies obtained using Kissinger analysis and is markedlydifferent in crystallization kinetic behaviour compared to that of other BMGswith better glass forming abilities. An apparent correlation between crystallizationtemperature and activation energy is found in various metallic glasses. Thecorrelation is discussed and connected with the thermal stability of metallicglasses.