CeO2对Mg-PSZ陶瓷显微结构和相组成的影响

在氧化镁部分稳定氧化锆基质原料中加入不同含量的CeO2,研究烧结、热处理过程中(Ce,Mg)-PSZ显微结构和相组成的变化。结果表明:CeO2的加入可促进高温下Mg2+在固溶体中的扩散,避免MgO在晶界偏析,有利于晶界净化;随CeO2含量增加,烧结体中晶粒尺寸减小,四方析出体更为稳定,不规则形态的立方氧化锆晶粒和波浪式晶界明显增多。通过热处理,相邻立方晶粒中四方析出体相互交联,最终(Ce,Mg)-PSZ基体中的晶界消失,颗粒合并,析出体交联形成连续态网络结构。

Effects of CeO2 on microstructure and phase constituent of Mg-PSZ ceramics

A ternary partially stabilized zirconia materials((Ce,Mg)-PSZ)have been prepared by ceria doping in 10mol% Mg-PSZ ceramics.The microstructure and stability of t-zirconia during sintering and annealing were investigated.The results show that the combination of Mg-O is weakened by the interaction of ionic Ce on the O2-of MgO,and improves the ionic diffusion in solid state to avoid MgO segregation on the grain boundary.With the amount of ceria increasing,the grain size decreased while the(t,c)-ZrO2 phase fraction increased and the irregular cubic zirconia grains and undulated grain boundaries increased.By heat treatment,tetragonal precipitates embedded in an adjacent coarse-grained cubic matrix weaved into network.Microstructure of(Ce,Mg)-PSZ ceramics with continuous network was obtained by grain merging.