Water solubility in quartz and its influence on ductility
Cordier, Patrick; Doukhan, Jean-Claude
European Journal of Mineralogy Volume 1 Number 2 (1989), p. 221 - 238
published: May 3, 1989
manuscript accepted: Jan 25, 1989
manuscript received: Jul 15, 1988
ArtNo. ESP147050102007, Price: 29.00 €
Abstract The deformation of wet synthetic quartz at moderate temperature is accompanied by a continuous change of the state of dispersion of water (precipitation) ; other relevant parameters of the deformation process like flow stress or strain hardening are affected by this phenomenon. We have characterized experimentally the solubility of water in quartz as a function of pressure at a given temperature (700 °C). Wet samples have been annealed at this temperature and under various confining pressures ; then they have been observed by TEM to check if water had precipitated or not. We find that the solubility increases with pressure and reaches a value of 50 to 100 at. ppm at 800 MPa. We then deformed wet quartzes with a homogeneous water content at T,P conditions such that, in one case, it was lower than the equilibrium concentration while, in the other case, it was only slightly larger. Only glide is observed in the first case while in the supersaturated crystals, dislocation climb is the prominent feature at the same T,P and è deformation conditions.