Microwave sintering of Dy2O3-doped aluminum nitride

초록

AlN ceramics have been used for substrates, packaging materials for high power integrated circuits for electronic devices, refractive materials in the metallurgical industry and so on. However, due to its high covalent bonding, it is difficult to achieve the high sintered density through normal solid-state sintering without using sub-micrometer powders or high pressures below 1800oC. Application of microwave for sintering ceramic materials has a lot of advantages such as fast heating rate, energy efficiency, volumetric and uniform heating. In order to improve the sintering, the most common additives such as rare-earth and/or alkaline earth oxides have been used. The microwave sintering of AlN with Dy2O3 as a sintering additive was carried out at a sintering temperature as low as 1500–1600oC. The effect of sintering temperature and sintering aid (i.e., Dy2O3) on the densification, microstructure and thermal conductivity of AlN sample was investigated. The addition of Dy2O3 (1, 3, 5 wt.%) improved the properties and density of AlN. AlN sample with a high sintered density was obtained through microwave sintering at below 1600oC while maintaining a fine grain structure.