Plastic Deformation of Covalent Bonded Ceramics at High Temperatures

A review is given on our recent investigations concerning the high temperature deformation mechanism of covalent bonded ceramics, titanium carbide (TiC) and silicon carbide (SiC). Particular attentions have been paid to the effect of nonstoichiometry and to the effect of polytypes and addition of sintering aids on their high temperature deformation behavior for TiC andSiC, respectively. The observed phenomena are discussed from the viewpoints of the characteristics of dislocation motion, then the importance of understanding the nature of dislocation motion even for ceramics is emphasized.