Influence of La2O3 Addition on Microstructure and Mechanical Properties of Al2O3 Ceramics

In this paper, alumina ceramics were prepared with alumina powder and lanthanum nitrate. The influence of La2O3 on the microstructure and properties of alumina ceramics were studied. The result showed that the addition of La2O3 contributed to the mechanical property of the samples. The alumina ceramics with adding of 0.05wt% La2O3 sintered at 1490°C had the best mechanical properties. And the flexural strength, fracture toughness of the ceramics could reach 571.902MPa and 5.82MPa•m1/2，which were improved by 37.55% and 10.65% respectively compared with the alumina ceramics without La2O3. Besides, the average grain size of alumina ceramic is about 2.8μm, and the effect of inhibition on grain growth of alumina ceramics was obvious.