Yb-Ce-TZP的断裂相变量与力学性能

THE TRANSFORMED AMOUNT DURING FRACTURE TESTING AND MECHANICAL PROPERTIES OF Yb-Ce-TZP

用XRD研究了Yb-Ce-TZP断裂前后的相组成.分析了烧结温度、相对密度、稳定剂及晶粒尺寸与相变量间的关系讨论了相变量对力学性能的决定作用发现：复合稳定剂可显著提高断裂相变量，有效改善TZP的力学性能稳定剂含量为0．75％Yb2O3imi＋9％CeO2（mol百分数）时可获得最大断裂相变量，其力学性能显著优于Yb-TZP和Ce-TZP．

The tetragonal zirconia polycrystals containing Yb2O3 and CeO2 (Yb-Ce-TZP) with high fie-cural strength and toughness were obtained by using nanopowders as raw materials. The stabilizing agents were added to the specimen by mixing Yb2O3, CeO2 and ZrO2 nanopowders proportionally in ethyl alcohol. The specimen were sintered at an ambient pressure and 1430～1580℃ for 2 h. XRD was employed to investigate the phase composition for the Yb-Ce-TZP materials before and after fracturing. The grain size was determined by SEM. The relationship between the sintering temperature,density, stabilizing agent composition, grain size and monoclinic phase increment (Vt→m) was studied. It was found that the higher Vt→m was obtained at 1530℃, at which the grain size is 1.8-2.μm. Meanwhile, There was a more Vt→m apparently and improve the mechanical properties. The Yb-Ce-TZP containing 0.75% Yb2O3 and 9% CeO2 (in mol) showed the best mechanical properties, which is superior to that of Yb-TZP and Ce-TZP. It was concluded that the composite stabilizing agents can raise the monoclinic phase increment by increasing the transforming ability of tetragonal phase, which is probably by way of deforming the crystallinic structure of tetragonal zirconia.