The Effect of Sintering Process Cycle on Thermal Conductivity and Surface Characterization of Si3N4 Ceramics Produced with Submicron Sized Starting Powder

Abstract

The need for control of temperature rise in electronic devices is a fundamental cause of the production of high thermal conductivity substrate materials. By controlling the parameters affecting thermal conductivity Si3N4 ceramics, materials with suitable properties for the industrial applications can be developed. Two important parameters affecting the thermal conductivity of Si3N4 ceramics such as density and grain boundary phase depend on sintering additives and techniques. In the sintering, the gas application time and the sintering cooling cycle are the factors affecting the phase crystallization. The amount and distribution of the phases formed in the microstructure after sintering affect the thermal conductivity. In this study, the effect on microstructure and thermal conductivity of different cooling cycles of Si3N4 ceramics gas pressure sintered with Y2O3 addition to Si3 N4 starting powder (<1 µm) was investigated. Thermal conductivity was 42.69 W/m.K with slow cooling and 44.18 W/m.K with rapid cooling. With slow cooling, density decreased, open porosity increased, thermal conductivity decreased by ~ 3.5% ratio. © 2020, TUBITAK. All rights reserved.