An approach to developing mesoscale mechanical models of refractory spinel ceramics and assessing the influence of structural defects on macroscopic mechanical and thermal properties

Abstract

The paper discusses the keystones of developing mesoscale computer models of refractory ceramic materials with multiscale internal structure. The study is carried out on several promising materials based on aluminum-magnesium spinel with different fractional compositions of grains. The mechanical model is based on the representation of the refractory as a dispersion-hardened composite with a porous fine-grained matrix and mesoscale inclusions (large grains). The model takes into account two types of structural defects in the material: pores and planar discontinuities. Using the model, quantitative estimates of the mechanical characteristics of large grains, conglomerates of fine grains in the matrix, and grain-matrix interfaces are obtained. The contributions of pores and planar discontinuities to the macroscopic mechanical characteristics and thermal conductivity of two promising spinel ceramics synthesized from mechanically activated powders are determined.