部份稳定化氧化锆陶瓷的冲蚀磨损和断裂的研究

Erosive Wear and Fracture of Partially Stabilized Zirconia Ceramics

用石英砂、碳化硅的两种磨粒对成分相同但处理成亚稳态四方相(T)含量不同从而断裂韧性K_(Ic)不同的两种氧化镁稳定的部分稳定化氧化锆(Mg-PSZ)陶瓷进行了冲蚀磨损试验,测定其断裂韧性.用X-射线衍射法测定K_(Ic)断口与冲蚀表面的T相转变量,并对断口及单颗粒和多颗粒冲蚀表面进行电子显微观察.结果表明,石英砂冲蚀主要依压痕、侧向裂纹的方式发生,而碳化硅冲蚀则依切入导致块状断裂及特殊的碎化断裂发生;碳化硅产生的冲蚀率明显大于石英砂;四方相向单斜相转变对PSZ材料的冲蚀抗力有贡献,PSZ材料冲蚀的速度指数m较低;两种Mg-PSZ的K_(Ic)值有相当的差别,其冲蚀抗力虽有改善,但不很显著。

The crosive wear MgO-partilly-stabilized zirconia ceramics heat treated to exhibit two varied contents of metastablc tetragonal phase, having different K_(lc) values, have been investigated using silica and silicon-carbide abrasives as the erodent. The degrees of tetragonal transformation of eroded surfaces and K_(lc) fracture surfaces were determined by X-ray diffraction method. The eroded surfaces due to single and multi-particle-impact were analysed by SEM. It is shown that the erosion rates under silicon-carbide abrasives were higher than that under quartz abrasives. Their different erosion process has been discussed. The erosion resistance can be enhanced by transformation toughening from tetragonal to monoclinic system of PSZ ceramics. The velocity exponent m of PSZ ceramic is lower than that of other ceramics.