High thermal conductivity of spark plasma sintered silicon carbide ceramics with yttria and scandia

Abstract A fully dense SiC ceramic with a room‐temperature thermal conductivity of 262 W·(m·K) −1 was obtained via spark plasma sintering β‐SiC powder containing 0.79 vol% Y 2 O 3 ‐Sc 2 O 3 . High‐resolution transmission electron microscopy revealed two different SiC‐SiC boundaries, that is, amorphous and clean boundaries, in addition to a fully crystallized junction phase. A high thermal conductivity was attributed to a low lattice oxygen content and the presence of clean SiC‐SiC boundaries.