ZrO_2-2mol%Y_2O_3陶瓷显微结构及性能的研究

AN INVESTIGATION ON MICROSTRUCTURE AND PROPERTIES OF ZrO_2-2mol%Y_2O_3 CERAMICS

本文采用X射线衍射分析、扫描及透射电镜技术研究了冷等静压成型的氧化钇部分稳定氧化锆(Y-PSZ)陶瓷制品的相组成、显微结构、机械性能及其与烧结工艺之间的关系。结果表明:采用冷等静压成型和超细的氧化锆粉末有利于提高制品的烧结密度和获得较理想的显微结构。得出了在细晶部分稳定氧化锆中存在适量的单斜相也能获得高硬度和高韧性的结论。1600℃烧结3h后随炉冷却的ZrO_2-2mol％Y_2O_3试样的维氏硬度达16.75GPa,断裂韧性高达17.56MPa·m^(1/2)。这被认为是细晶粒、高密度及微裂纹增韧、相变增韧共同作用的结果。

The phase content, microstructure, mechanical properties of zirconia ceramics partially stabilized by yttria (Y-PSZ), and its relationship with sintering process were investigated by means of X-ray diffraction, SEM and TEM. The samples used were compacted by cold isostatic pressing and sintered at various temperatures. The results show that cold isostatic pressing and the ultra fine zirconia powder are beneficial for improving the sintering density and microstructure. It is concluded that higher strength and better toughness can be obtained by mixing tetragonal and suitable monoclinic phase in fine grain Y-PSZ too Vicker's hardness and fracture toughness of ZrO_2-2 mol% Y_2O_3 samples sintered at 1600℃ for 3h followed by slow cooling will be 16.75 GPa and 17.56 MPa-m^(1/2) respectively. The satisfactory hardness and toughness obtained may be considered as the combined effect of fine grain size, high density and toughening of microcracks and phase transformation.