Abstract
Thermal response in silicon nitride materials was investigated locally with a micro-thermal analyzer. Three grades of silicon nitride materials, SN-H, SN-L, and SN-A, were examined. SN-H was ultimately fired at 2473K, SN-L was fired at 2273K, and SN-A contains Al2O3 as a sintering aid. Bulk thermal conductivities of SN-H and SN-L were 132.3W/(m·K) and 104.7 W/(m·k), respectively. Micro-thermal analysis revealed that the local thermal conductivity of silicon nitride grains was higher in SN-L than in SN-H, contrary to the results seen for the bulk thermal conductivities. The discrepancy in grain and bulk thermal conductivities is discussed.
