A study of liquid enhanced creep in porous potassium chloride
Pharr, George M.
Master of Science
This research was a study of liquid enhanced creep in cold compressed potassium chloride whose grain boundaries were filled with saturated aqueous solution of KC1. This liquid was found to greatly accelerate the rate of creep in the material. It was found that two independent deformation mechanisms operate. The first occurs at low stresses (.163 MPa and below) and it is characterized by a linear stress dependence. The second mechanism dominates at higher stresses (.32 MPa and above), and is characterized by a stress exponent of two. The mechanisms are documented in terms of differences in volumetric strain behavior, creep ductility, and grain size dependence. It is suggested that the low stress mechanism is a diffusional one, similar to Coble creep with the liquid acting as a rapid diffusion path for transport of the solid. The high stress mechanism is not yet clearly understood, but is shown to involve grain boundary sliding accomodated by internal cavitation.