Experimental determination of the elasticity of porous ceramics under the gas saturation and temperature treatment

After the formulation of the theory of poroelasticity, which describes the elasticity of fluid saturated porous media, many experimental studies have been reported on the determination of the elasticity of porous materials under the various physical and structural conditions. However, there are limited studies on how the elasticity behave under the variation of the physical conditions of the saturated fluid. This study presents an attempt to characterize the influence of the pore-saturated gas media and their physical properties on the elasticity of porous ceramic materials. Resonant ultrasound spectroscopic measurements were performed on test specimens of alumina with ∼40% porosity, zirconia with ∼48% porosity, and sintered fully dense zirconia to determine the hydrostatic pressure-dependent macroscopic elasticity. Here, we report the variation of elasticity of porous and full dense samples over approximately five orders of magnitude (800–0.02 psi) in absolute pressure. A material softening with increased pressure was observed from the porous specimens and the rate of softening is quantified with different gas saturation by helium, nitrogen and argon. The time evolution of mechanical equilibrium of the porous materials at low pressure (0.02 psi) and moderately high-temperature (150 °C) conditions will also be discussed.