Inelastic behavior of ceramics with hierarchical pore structure under compression

The compaction behavior is studied in Аl$_{2}$O$_{3}$ ceramics with a pore space volume in the range from 35 to 60% and with the following three types of hierarchical pore structure: coarse porosity with a size of 80 to 100 $\mu$m, fine porosity with a size of 14 to 15 $\mu$m, and intermediate interblock porosity comprised of elongated (110–120 $\mu$m) porous microchannels formed as a result of zonal isolation during sintering. It is shown that the obtained hierarchical porous structure causes the formation of a hierarchical deformation structure in the volume of ceramics and leads to a decrease in the extent of destruction processes from the macroscopic scale in the case of unimodal ceramics to the microscale destruction comparable with the sizes of the blocks formed during sintering.