| Abstract: | General features of silicon nitride based ceramics, which may well influence their creep behavior are presented. Then, the most commonly invoked models for the microscopic mechanisms assumed to take place during creep (viscous flow, solution-precipitation, cavitation and shear thickening) are analyzed. Finally, the very numerous macroscopic and microscopic experimental findings about the plastic deformation of silicon nitride based ceramics at high temperatures, such as the fundamental role played by the secondary phases, the essential compressive-tensile asymmetry, and the microstructural evolution accompanying creep are summarized and discussed in terms of those models. |
