Thermal conductivity of liquid phase sintered silicon carbide

This study investigates the thermal diffusivity and conductivity of YAG/AlN-alloyed LPS-SiC as a function of composition and temperature using the laser-flash technique. Maxwellʹs model for the thermal conductivity of composites with spherical inclusions is adapted to typical features of the LPS-microstructure and its predictions are compared with experimental data. The results indicate that the thermal conductivity of LPS-SiC is controlled by (i) concentration of impurity atoms in the SiC-phase, (ii) fraction of bulk oxide phase and (iii) amorphous interphases which act as thermal resistance barriers.