抄録
Microstructural evolution during the sintering of nanoceramics was investigated in the compacts prepared by gelcasting of tetragonal zirconia nano-slurry with the solid loading of 7 vol %. The initial compact prepared by the gelcasting in this study had the densely packed structure with a narrow pore-size distribution and high connectivity in the particle network. Special attentions were paid to the evolutions of pore structures in the initial and intermediate stage sintering. It was found that the coarsening of the pores, which is thought to be the important obstacle of the densification in nanoceramics, was not remarkable in the sintering of the densely packed compact. The suppression of the pore coarsening resulted in the lowering the sintering temperature. Almost fully dense sample with 99.5% of theoretical density was successfully obtained at the sintering temperature of 1373 K for 2 h. The sample sintered at 1373 K maintained the nanometric structure with the grain size of 79 nm and exhibited the optical translucency.
