The Stress-Time Relation in Glass during Annealing

JSGT 1955 V39 T099-T112

A discussion is presented of the release of internal stress in glass at constant temperature, based on a simple viscous-flow mechanism with the viscosity increasing linearly with time as suggested by Douglas & Isard. Data published by Lillie are shown to be in excellent agreement with this interpretation. Some implications of a linearly-increasing viscosity are discussed in connection with the corresponding change of fictive temperature as determined by the increase of the density of a borosilicate crown glass with time.

H. N. Ritland