Effect of particle shape and arrangement on thermoelastic properties of porous ceramics

Thermoelastic properties of various bi-continuous porous ceramics are simulated by a new finite element model. The model considers various particle shapes which allow for an independent variation of pore volume and particle contact area. Phenomena like neck formation, agglomeration, particle size distribution and coordination are included in the model geometry. Particle arrangement is modelled using cubic super cells as well as random particle positions. Young's moduli, Poisson's ratios and stress concentration factors are simulated and thermal shock resistance is estimated from these data. A close correlation between thermal conductivity and Young's modulus is found for all types of microstructure. Stress concentration is strongly affected by the particle shapes in the contact region.