Nonisothermal creep of bulk Zr52.5Ti5Cu17.9Ni14.6Al10 metallic glass

The article presents the results of nonisothermal creep measurements of the Zr52.5Ti5Cu17.9Ni14.6Al10 bulk metallic glass in a wide range of heating rates well below and in the vicinity of the glass transition temperature T-g. It is shown that the shear viscosity eta is strongly dependent on the heating rate T:eta increases linearly with T-1 at T<T-g, while an increase of eta with T is observed at T>T-g. It is argued that the heating rate dependence of the shear viscosity below the glass transition region is controlled by irreversible structural relaxation and can be quantitatively described by the directional structural relaxation model. A possible reason for the eta(T) dependence in the glass transition region is discussed. (C) 2002 American Institute of Physics.