等轴晶ZrO_2(Al_2O_3,Fe_2O_3)复相陶瓷的制备

Preparation of Equiaxed Grains of Multiphase ZrO_2(Al_2O_3,Fe_2O_3) Ceramics

讨论了以硝酸盐溶液为原料,经喷雾干燥、热解、成型、烧结或直接烧结制备等轴晶ZrO2(Al2O3, Fe2O3)复相陶瓷的过程. 研究了成型压力、烧结温度、恒温时间及Al3+, Fe3+的加入对ZrO2陶瓷的相组成、晶粒大小和形貌的影响. 结果表明:成型压力对相组成及晶粒尺寸无明显影响;无论是直接采用硝酸盐复合粉末还是采用氧化物粉末压坯作为前驱物,烧结产物的形貌、相组成不变;加入Fe2O3可克服微观结构层状堆垛,获得相对细小均匀的等轴晶粒,且随Fe2O3含量的增加,单位体积中a-(Al, Fe)2O3核心的数量增加,晶粒尺寸更加细小、均匀,Fe2O3含量相对于Al2O3在20%左右时效果最佳;各相晶粒在长时间高温烧结时生长速度较为缓慢,0.5 h为0.5 mm左右,烧结12 h才到2.0 mm左右.

Amorphous composite powders are prepared by spray drying via nitrate solution precursors, and multiphase zirconia-based ceramics in the form of equiaxed grains are synthesized either by mean of direct sinteringof the composite or by mean of sintering after pyrolysis and moulding. The effects of moulding pressure, sintering temperature, sintering period and dopants of Al3+ and Fe3+ on the structure of phases, the size and micrographs of grains are discussed.