纳米ZrO_2(4Y)的快速高压烧结研究

RAPID SINTERING OF NANOCRYSTALLINE ZrO_2(4Y) POWDER UNDER HIGH PRESSURE

纳米Y2 O3 稳定的ZrO2 粉在 4GPa高压下、10 0 0～ 12 0 0℃烧结 2min致密成型。完整块体致密度为 99.3%。在高压烧结过程中 ,由于外加压力对扩散的促进作用 ,活化能比用其它方法烧结时降低 ,约为 4 8kJ/mol,晶粒长至 4 0～ 70nm。四方度及晶胞体积略小于常压烧结样品的数值。高压快速烧结ZrO2 (4Y)陶瓷为棕色、深灰色或黑色。快速高压烧结所得样品结构存在某种非均匀性。

Nanocrystalline ZrO2 (4Y) powders were sintered under 4 GPa and at 1000-1200°C for 2 min. The results show that the relative density of undamaged sintered ceramics body is 99.3%. In the sintering process under high pressure, activation energy is less than that by other method because of the effect of applied pressure on diffusion. The activation energy is about 48 kJ/mol. Crystal grains ranges from 40 to 70 nm. The ctat-1 size and unit cell volume of the t-ZrO2 is smaller than that sintered under normal pressure. The color of ZrO2 (4Y) is brown, dark gray and black. The structure of ZrO2(4Y) is not homogenous.