La_2O_3对ZTM陶瓷晶界性能的影响

EFFECT OF La_2O_3 ADDITION ON GRAIN-BOUNDARY CHARACTERIZATION OF ZTM CERAMICS

以电熔莫来石为原料制备的ＺｒＯ２增韧莫来石陶在在高温下力学性能不像莫来石那样随温度升高反而呈现有所增长的趋势．研究发现这一变化与原料中含有的Ｋ，Ｎａ等有害杂质有关．本文主要研究以稀土氧化物（Ｌａ２Ｏ３）做添加剂来抑制或消除该陶瓷玻璃相中存在的有害杂质的作用，从而改善ＺＴＭ陶瓷的力学性能，并探讨Ｌａ２Ｏ３对ＺＴＭ陶瓷晶界改性的作用机制．

High-temperature properlies of zirconia-toughening mullite ceramics prepared by using electrically-fused mullite are decreased because of more impurities in glass-phases, which contrasts the ceramics done by using high-purity mullite. It is found that this phenomenon is mainly relative to impurities,such as K+ and Na+, contained in raw materials. In this paper, the approach by which mechanical properties of the ceramics are improved by adding rare-earth oxide (lanthanum oxide) was studied and thier mechanism was also discussed.