CHANGE IN PORE STRUCTURE OF YTTRIA-STABILIZED ZIRCONIA DURING SINTERING

The behavior of coarse and fine pore channels and closed pores (pore space components) in temperature ranges of intensive (900-1150 degrees C) and less active (1150-1400 degrees 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 mu m) pore channels are broken and new closed pores are formed.