Silicon nitride materials featured by superior creep and fracture resistance at 1400 degree Celsius

The two materials investigated exhibit an acceptable niveau in fracture toughness in combination with a high creep resistance at 1400 degree C. As possible reasons are supposed: the crystallization of the grain boundary phase; the microstructural design of the materials; the formation of different grain boundary compositions between the different grains (Si3N4 and SiC, alpha- and beta-Si3N4-grains). Meanwhile the alpha-beta-sialon suffers a strong oxidation enhanced SCG the nanocomposite material was found as a promising candidate for long-term applications.