Microstructure of liquid phase sintered superplastic silicon carbide ceramics

Superplastic silicon carbide ceramics were fabricated at low temperatures by a liquid phase sintering very fine β–SiC powder. The microstructural features of this material, of both before and after the superplastic deformation, have been investigated by transmission electron microscopy. Evaluated from the point of view of phase transformation, dislocation motion, and dynamic grain growth, the materials show very stable microstructures, indicating that the superplastic deformation process was dominated by the liquid phase assisted grain boundary sliding. In addition, the material is also characterized by the formation of clusters of fine SiC particles (5–20 nm) encapsulated in layered graphitized carbon.