The viscosity and flow stress of a bulk Pd40Ni10Cu30P20
alloy glass near the glass transition were measured as a function of temperature and strain rate under compression. The steady-state viscosity of the glass for a given temperature remains constant at low strain rate, then decreases by many orders of magnitude above a critical strain rate. A master curve in term of the viscosity ratio η/ηN
and the product ηN
has been constructed, where η and ηN
are, respectively, the steady-state viscosity and Newtonian viscosity, and
is the strain rate. The flow stress also can be represented in terms of the product ηN.
The master curves are fitted with a simple stress relaxation of the form 1−exp[−t/λ]
with t = −1.
© 1998 American Institute of Physics.