Деформация и разрушение корундовой керамики с многоуровневой поровой структурой

It has been studied the behavior under compression tests of alumina ceramics with multilevel pore structure. The porosity approximately was 50% and included pores of three types - large pores with an average size of 120 µm, small porosity with an average size of 2 µm and extended pore channels about 150 µm length formed as a result of zonal shrinkage during sintering. It was shown that during loading of material with this multilevel pore structure there are arising micro-damages in whole sample and as result in a lowering a scale level of fracture from macro- to meso- and microlevel. Residual strain is appears even at a very low stresses smaller 30% of material strength only due to movements of separate blocks formed after sintering.