The effect of varying water contents on the creep behavior of Heavitree quartzite

With increasing available water, Heavitree quartzite samples deformed in the dislocation creep regime at a pressure of 15 kbar are progressively weaker and show a decrease in both the stress exponent and the activation energy for creep. The vacuum-heated (strongest) samples have the least evidence of recovery within the original grains and no grain boundary recrystallization or melt, whereas the water-added (weakest) samples have abundant evidence of recovery, relatively coarse recrystallized grains along the original grain boundary, and small amounts ( less than 3%) of grain boundary melt. The grain boundary recrystallization and melting promoted by the water may allow a component of grain boundary sliding, which would explain the low stress exponent for the water-added samples, but there is no microstructural evidence for this mechanism.

The effect of varying water contents on the creep behavior of Heavitree quartzite Academic Article