The single crystal elastic constants of hexagonal SiC to 1000°C

Abstract

The relationships between the sound velocities in the cubic and hexagonal crystal structures and the tensor transformations for the two structures are applied to determine the elastic stiffnesses, C_ij and (dC_ij/T) for the hexagonal structures of SiC to 1000°C. These results are then applied to calculate the polycrystalline elastic moduli, E and G, and their temperature variations. The calculated values for E and G at 20°C are 420 and 180 GPa and for (dE/dT) and (dG/dT) the values are −0·020 and −0·007 (GPa/°C), respectively. These agree well with published experimental values for E and G of dense polycrystalline alpha silicon carbides.