The influence of the pore size and distribution on the mechanical properties of a brittle ceramic

Abstract

The present paper aims to clarify porosity effects on mechanical properties (Young's modulus, compressive strength) of a porous Si-based ceramic by means of numerical simulations. For this purpose, we conducted two parametric studies (i) varying the pore distribution in the bulk of the material, with the pore size and number being the same; (ii) varying the pore size, number and distance between them with the same porosity of specimens under study. The distribution of pores with all other conditions being equal is shown to have a significant effect on the crack initiation strain and the location of the first crack, while the Young's modulus appeared to be almost unaffected (maximum 1.4% deviation from the average value). The maximum equivalent stresses are observed to increase with increasing ratio of the distance between pores to their radius.