M. Koide et al., APPARENT VISCOSITY AND RELAXATION MECHANISM OF GLASSES BELOW GLASS-TRANSITION TEMPERATURE, Physics and Chemistry of Glasses, 38(2), 1997, pp. 83-86
The deformation mechanism of silicate glasses was analysed by the fibr
e bending method far below the glass transition temperature based on a
stretched exponential decay function of relaxation time; I - psi = ex
p[-(t/tau) b]. The effects of atmospheric humidity were not observed.
The relaxation time was found to increase with decreasing temperature
and with pre-annealing heat treatment below glass transition temperatu
re. In addition the stretching parameter increased with pre-annealing
heat treatment of temperature suggesting wider distribution of relaxat
ion time in the quenched sample, and that the glass approaches a more
stable state by pre-annealing heat treatment even far below the glass
transition temperature. It was also found that the activation energy f
or relaxation inn eases with ina easing pre-annealing temperature and
time.