초록 |
Silicon nitride (Si3N4) is a useful ceramic material for various technical applications such as electronic substrate materials due to its excellent properties: outstanding mechanical properties, high chemical stability, good thermal shock resistance and so on. In this study, the Si3N4 was pressureless sintered with various rare-earth oxide additives and its mechanical and thermal properties were investigated. The sintering additive systems consisted of MgO as a basic fixed additive, Y2O3, Yb2O3, La2O3 as rare-earth oxide additives, and SiO2 as a non-rare-earth oxide additive, whose properties were evaluated. In order to investigate the factors affecting the thermal conductivity, the distribution of the secondary phase in grain boundary were investigated. Furthermore, the analysis of thermal conductivity was approached by using Raman spectroscopy instead of the conventional laser flash method. |