Abstract The influence of La2O3 inclusion (0 – 3 wt%) on the microstructure, phase formation and mechanical properties of Zirconia Toughed Alumina (ZTA) added with 5.0 wt% CeO2 was investigated. ZTA CeO2 composites were sintered at1600 °C for 4 h. The microstructure, phase formation, density, fracture toughness and hardness properties were characterised through FESEM, Microscopy Image Analysis Software and XRD diffractometer, Archimedes principle and Vickers indentation technique, respectively. The XRD, image processing and FESEM revealed the existence of LaAl11O18. The addition of La2O3 incited the sintering, microstructure refinement, densification of ZTA-CeO2 matrix and phase transformation. Hence, the hardness of ZTA-CeO2 ceramics was increased rapidly based on refinement of Al2O3 grains, densification of ZTA-CeO2 composites and porosity reduction. It was observed that the fracture toughness was enhanced through in situ formation of elongated LaAl11O18 grains. The addition of 0.7 wt% La2O3 culminated in the achievement of the optimum findings for density (4.41 g/cm3), porosity (0.46 %), hardness (1792 HV) and fracture toughness (8.8 MPa·m1/2). Nevertheless, excess La2O3 was proven to be detrimental as it displayed poor mechanical properties due to the poor compactness of numerous LaAl11O18 grains, coarsening of Al2O3 grains and decline in density.

中文翻译：

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La2O3 添加对具有可持续高断裂韧性的较硬 ZTA-CeO2 复合材料的微观结构发展和物理性能的影响

摘要 研究了 La2O3 夹杂物 (0 – 3 wt%) 对添加 5.0 wt% CeO2 的氧化锆韧化氧化铝 (ZTA) 的微观结构、相形成和机械性能的影响。ZTA CeO2 复合材料在 1600 °C 下烧结 4 小时。分别通过FESEM、显微图像分析软件和XRD衍射仪、阿基米德原理和维氏压痕技术对显微组织、相形成、密度、断裂韧性和硬度性能进行了表征。XRD、图像处理和FESEM 揭示了LaAl11O18 的存在。La2O3 的加入促进了 ZTA-CeO2 基体的烧结、微观结构细化、致密化和相变。因此，基于 Al2O3 晶粒的细化，ZTA-CeO2 陶瓷的硬度迅速提高，ZTA-CeO2 复合材料的致密化和孔隙率降低。观察到通过拉长的 LaAl11O18 晶粒的原位形成提高了断裂韧性。添加 0.7 wt% La2O3 最终实现了密度 (4.41 g/cm3)、孔隙率 (0.46%)、硬度 (1792 HV) 和断裂韧性 (8.8 MPa·m1/2) 的最佳结果。然而，过量的 La2O3 被证明是有害的，因为许多 LaAl11O18 晶粒的致密性差、Al2O3 晶粒粗化和密度下降，因此它显示出较差的机械性能。硬度（1792 HV）和断裂韧性（8.8 MPa·m1/2）。然而，过量的 La2O3 被证明是有害的，因为许多 LaAl11O18 晶粒的致密性差、Al2O3 晶粒粗化和密度下降，因此它显示出较差的机械性能。硬度（1792 HV）和断裂韧性（8.8 MPa·m1/2）。然而，过量的 La2O3 被证明是有害的，因为许多 LaAl11O18 晶粒的致密性差、Al2O3 晶粒粗化和密度下降，因此它显示出较差的机械性能。