The Newtonian viscosity of the supercooled liquid measured by the continuous-strain-rate tensile test was investigated in the Pd40Ni40P20
metallic glass. It was found that continuous-strain-rate tests were applicable to determine the viscosity over a wide strain-rate region, and that the measured Newtonian viscosity η0
corresponded to the equilibrium one. The viscosity η over the entire strain-rate interval could be well described by one master curve expressed with a stretched exponential function η/η0 = 1−exp(C/β)
in which β was 0.82. The free-volume-theory relation proposed by Cohen and Grest reproduced the equilibrium viscosity data over the entire temperature region better than the famous Vogel–Fulcher–Tammann relation. The supercooled liquid of the Pd40Ni40P20
metallic glass was classified into the relatively strong liquids as well as the other metallic glasses. The Pd40Ni40P20
metallic glass that is a metal-metalloid alloy exhibited to be more fragile than metal–metal glasses. © 2000 American Institute of Physics.