氧化锆(氧化钇)-氧化铝陶瓷的透射电子显微分析

ANALYSIS OF TRANSMISSION ELECTRON MICROGRAPHY IN ZrO_2 (Y_2O_3)-Al_2O_3 CERAMICS

氧化锆(ZrO_2)马氏体相变增韧是改善陶瓷材料性能的重要途径,研究 ZrO_2的马氏体形态对相变增韧具有重要意义,本文利用透射电镜研究了 ZrO_2(Y_2O_3)-Al_2O_3陶瓷中各相的形态。观察分析表明 ZrO_2(Y_2O_3)固溶体中马氏体相变有两种类型:第一类马氏体(M_Ⅰ),其孪生面为(010)、(001)、(011)和(011);第二类马氏体(M_Ⅱ),其孪生面只可能是(011)和(011)。并在 M_Ⅰ中发现相变后形成的形变李晶,在 M_Ⅱ中发现二次衍射参与成象后形成的水纹图。还发现在未转变的面心四方(FCT)相 ZrO_2(Y_2O_3)固溶体中,局部区域出现调幅结构。

Fine structures of all phases in ZrO_2(Y_2O_3)-Al_2O_3 ceramics are researched by means of TEM.Experimental results indicate that there are two types of martensite transformation in ZrO_2(Y_2O_3)-Al_2O_3.Tne authors identify them as M_Ⅰ and M_Ⅱ,respectively.The twinning planes in M_Ⅰ are (010),(001),(011) and (01(?)),the twinning planes in M_Ⅱ are only(011) and(01(?)).It is found that the defomation twins are formed in M_Ⅰ after t-m transformation,and the moire-pattern is formed due to the second diffraction in M_Ⅱ.It is also found that the spinodal structure appears in the local zones of retained t-phaso(FCT) in ZrO_2(Y_2O_3) solid solution.