Dislocation loops in α-silicon nitride single crystals

Abstract

Silicon nitride(Si3N4) is well known to be a most promising ceramic material for high temperature structural applications. It has high strength even at 1200°C and its fracture toughness is about 5 to 7 MPa•m½. Si3N4 has been manufactured on mass production lines as the compressor rotor for turbo chargers. For high temperature use, it is important to know the deformation characteristics of the material and the role played by dislocations and other defects. However, research on the nature of defects in Si3N4 has been limited considering the importance of Si3N4. In this study, we have examined defects in single crystals of Si3N4.