Effect of Sintering Parameters on the Phase Composition of Ceramic Based on Aluminum Oxynitride

Resumo

In this paper, we analyzed the methods of synthesis and sintering of aluminum oxynitride powders. Samples of a ceramic material based on aluminum oxynitride were produced. The effectiveness of two sintering methods in induction and resistance furnaces was evaluated in the temperature range of 1750–1950°C and for the exposure time from 2 to 10 h. Structures of the obtained samples were studied by scanning electron microscopy, while the phase composition was studied using X-ray phase analysis. The effect of the heating parameters, sintering atmosphere, and quality of the initial powders on the formation of the aluminum oxynitride phase was considered. A sample sintered in a vacuum furnace without a nitrogen atmosphere did not have the aluminum oxynitride phase because of the release of nitrogen from the sample volume and had a strong shrinkage. Induction sintering in a nitrogen atmosphere made it possible to achieve ~85% concentration of the target phase, aluminum oxynitride, with density of 85% of theoretical (3.69 g/cm³). These results were obtained in the mode of exposure for 10 h at 1750°C.