Heat of evolution and non-Newtonian viscous flow of Pd40Ni40P20 glassy alloy

The evolution of specific heat of a Pd40Ni40P20 glassy alloy subjected to different degrees of non-Newtonian flow condition near the glass transition temperature, T-g, was investigated by a differential scanning calorimetry (DSC) method. Three exothermic relaxation spectrums were observed in temperature dependence of the specific heat. One of the relaxations in T > 490 K (= T-g - 95 K) strongly depended on the flow condition, on the other hand, the others did weakly. This relaxation has previously been reported and is due to the long-range disordering between metal and metalloid constituents. Thus, appearance of the non-Newtonian viscous flow in this glassy alloy is associated with the disordering of the glass skeleton framed with Pd-P and Ni-P coupling by the strong shear action.