氧化铈稳定氧化锆四方多晶体的制备及其力学性能研究

A STUDY ON THE PREPARATION OF CE-TZP AND ITS MECHANICAL PROPERTIES

选用价格便宜的CeO_2作稳定剂,制备了高性能的四方氧化锆增韧陶瓷Ce-TZP。与Y-TZP相比,这种新材料晶粒尺寸较为粗大,t-ZrO_2→m-ZrO_2相变临界尺寸较大,从而不需用超细粉末做原料即可制得性能较好的增韧ZrO_2陶瓷。试验发现,添加适量的Al_2O_3和TiO_2可使烧结温度明显降低,同时力学性能得到大幅度提高。本文对此进行了初步探讨并利用XRD、SEM及EDAX等实验手段对力学性能与显微结构的关系进行了初步的理论分析。本研究取得最高Vickers硬度值约9GPa,最高抗弯强度约为2.1GPa(标准离差0.63GPa),最高断裂韧性约14MPa·m^(1/2)(标准离差1MPa·m^(1/2))。

CeO_2, a rare earth oxide of lower cost, is selected as a stabilizer in the preparation of high quality ZrO_2 toughened ceramics, Ce-TZP. Compared with Y-TZP, this kind of material possesses coarser crystalline grains and correspondingly larger critical grain sizes in the transition of t-ZrO_2→m-ZrO_2, so that in the preparation of the high quality Ce-ZrO_2 ceramics, no ultrafine powder should be used as the raw materials. The addition of Al_2O_2 and TiO_2 is found to be very effective in lowering the sintering temperature and improving the mechanical properties at room temperature. The effects of the additives are discussed. The relationship between the mechanical properties and microstructure is investigated with the aid of XRD, SEM and EDAX. The maximum values of Hv, α, and K_(rC) are about 9GPa, 2.1±0.63GPa and 14±1MPa·m respectively.