The influence of porosity on the elasticity and strength of alumina and zirconia ceramics

Abstract

This work investigates the behavior of porous alumina (with the porosity ranging from 18% to 70%) and zirconia (with the porosity ranging from 10% to 60%) ceramics when subjected to deformation by compression and shearing. The analysis of stress-strain curves showed that there is a transition from a typical brittle state for relatively dense ceramics, to a pseudo-plastic one for ceramics with high porosity. The values of the effective Young’s modulus, effective shear modulus and Poisson’s ratio decrease with the increase of the pore space volume of ceramics, which correlates with the appearance of multiple cracking during the deformation of the high porosity ceramics.