Silicon-based non-oxide structural ce H 3 Fig. 3. Crystal structure of hexagonal a-SiC polytype 6H(P6, mc). View nearly along y-axis. Silicon atoms in red and Fig. 4. Crystal structure of cubic B-SiC polytype 6H 3C. View nearly along [101]-direction. Silicon atoms in red and carbon atoms in blueSilicon-based non-Qxide,~ructural ceramics 15 + , , . YT" Z 3 4 Fig. 3. Fig. 4. Crystal structure of hexagonal a-SiC polytype 6H (P63 mc). View nearly along y-axis. Silicon atoms in red and carbon atoms in blue. Crystal structure of cubic fl-SiC polytype 6H 3C. View nearly along [101]-direction. Silicon atoms in red and carbon atoms in blue