Low pressure dependent elasticity of porous ceramics

Abstract

The primary goal of this study was 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. The time evolution of mechanical equilibrium of the porous materials at low pressure and high‐temperature conditions will also be discussed.

Ultrasonic Characterization of Nanoparticle-Based Ceramics Fabricated by Spark-Plasma Sintering

“…As shown in [23], these effects can be considerably strong in the bulk nanoparticle-based materials, where pores are strongly anisotropic due to the preferred orientation of the flat particles. In contrast, the RUS method can be reliably applied to porous materials [36][37][38], as its results are not affected by the scattering at all. High quality of the peaks (i.e., small internal friction coefficients Q −1 ) can be achieved even in cellular materials with open porosity above 50% [39], provided that there is no energy dissipating mechanism in the material (cf.…”