Ce—TZP陶瓷的磨削应力诱发马氏体相变

THE GRINDING STRESS-INDUCED MARTENSITE TRANSFORMATION IN Ce-TZP

用磨削方法促成８．１０，１２Ｃｅ－ＴＺＰ及Ｙ２Ｏ３含量不同的Ｙ－８Ｃｅ－ＴＺＰ中的ｔ→ｍ相交，用ＸＲＤ作定量分析，讨论了成分及摩擦力对ＴＺＰ陶瓷中马氏体相变的影响，证明磨削应力正比于应力诱发单斜相的增量ｍσ；而ＣｅＯ２及Ｙ２Ｏ３含量对ｍσ的影响则有一极大值的关系；对照材料相应的断裂韧性，表明ｍσ与Ｋｉｃ；变化的一致性，进一步证实了ＴＺＰ陶瓷应力诱发相变增韧的本质．

n this work,the hand-grinding experiments with four abradants were used to study the Stress-induced martensite transformation in Ce-TZP and Y-8Ce-TZP ceramics.The volume fraction of monoclinic martensite was measured by XRD.The effects of frictional stress and the composition of TZP to the amount of the stress-induced martensite mσ(%)have been discussed.It is shown that the volume fraction of grinding-induced monoclinic phase mσ(%) is proportional to the applied grinding stress(σF),however mσ(%)changes with the content of CeO2(in Ce-TZP)and Y2O3(in Y-8Ce-TZP)in a manner that a maximum value of mσ(%)appears at-10mo1% CeO2 in Ce-TZP and ～ 0.5mo1% YZO,in Y-8Ce-TZP respeCtivety.A simple thermodynamic explanation is proposed for the above experimental results.It is also found that the variation of Kic with composition of Y-8Ce-TZP is parallel to that of mσ with composition,i.e the maximum value of Kic is also appeared in the speimens of 0.4-0.5 mo1% Y2O3.Therefore,the toughening mechanism by stress-induced transformation in Ce-TZP is further confirmed,and grinding as asimple,ready and verifiable method of detecting transformability of Ce-TZP ceramics is recognized again.