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[References: 14 tit.]

It has been studied alumina ceramics with multilevel porous structure consist of macro and micro pores, and porous channels separate of material blocks. Macro-pores were formed ultra-high molecular weight polyethylene and porous channels were formed due to zonal shrinkage during sintering of green body. The percentage ratio of these pore types are 15%, 30% and 55% for pore channels, fine and large pores, respectively. It has been shown that first cracks are formed almost from the beginning of deformations - approximately not more 30% of fracture strength and localized near blocks boundaries. It has been shown that a main fracture type under compression test is fractured of individual blocks without fracture of whole sample. This means that fracture scale level decrease from macroscopic to mesoscopic one.