Effects of Processing and Doping Elements on the Grain Boundary Microstructure and Mechanical Properties of SiC

摘要

Doping as well as processing methodology exhibited pronounced effect on microstructure and grain boundary character of SiC. Higher frequency of special boundaries, formation of α phase and extensive grain growth were observed in the Spark plasma sintering (SPS) samples as compared to the hot-pressed (HP) samples. Al doping further enhanced the frequency of special boundaries. An exaggerated grain growth was noticed with Mg doping. Finally, the hardness values measured on different SiC materials were related to the grain size as well as the grain boundary character.