The behavior of coarse and fine pore channels and closed pores (pore space components) in temperature ranges of intensive (900-1150°C) and less active (1150-1400°C) sintering of a sample pressed from nanosized powder of tetragonal zirconia solid solution is examined. The change in the volume of the sample in the temperature range of intensive sintering is determined by approximately equal decrease in the volume of coarse and fine pore channels, which originate from channels between agglomerates and between aggregates in the powder agglomerates. Closed pores of the sample originating from closed pores of the powder make a minor contribution to the decrease in volume since they contain air. In the temperature range of less active sintering, all fine (200-300 nm) and coarse (0.8-1 μm) pore channels are broken and new closed pores are formed.

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Low-temperature sintering of a tetragonal zirconia solid solution proceeds through the fracture of all agglomerates during pressing of samples from hydroxide powder coprecipitated from an aqueous solution and through the increased reactivity of amorphous zirconium hydroxide and oxide. Thermal treatment at 1100ºC for 1 h produces ceramics with relative density 0.928, grain size 120-135 nm, and pore size 50-75 nm. Sintering is most intensive in the temperature range 950-1150ºC and is less active in the range 800-950ºC.

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