Phase Stability - Structural and Microstructural Characterization of Al₂O₃-TiO₂ Ceramic Composites Reinforced with La₂O₃ Addition

Abstract

In this work, we have s produced Al2O3-TiO2 ceramic composites reinforced with rare earth oxide, lantânia (La2O3) ranging from 0 to 2 wt%, for the study of their phase stability, structureand microstructural chacteristics. The ceramic composites were produced by thermo-mechanical process. It was observed from the results of XRD after sintering no new phase is formed in addition to the characteristics of the precursor oxides. DTA shows the stability of the composites studied from 460oC temperature, meaning it does not present more phase changes. It was observed through the analysis of the results of X-ray diffraction after sintering the samples that no new phase is formed in addition to the characteristics of the precursor oxides indicating formation of the composite. However, there was variation in the peak concentration and intensities due to variations in the Al2O3 and La2O3 contents. The results obtained by scanning electron microscopy proved satisfactory with regard to good surface morphology, homogeneity and particle size distribution of the composite sintered at 1390oC for 40 hours. The samples with 1.0% and 1.5% La2O3 addition presented best results regarding these aspects