MICROSTRUCTURE AND THERMAL-SHOCK BEHAVIOR OF BN COMPOSITES

In the present study, the detailed microstructure of a number of BN-based materials has been investigated using electron optical techniques. The microstructures revealed by this analysis have been related to the thermal properties of BN. Several BN-based ceramic materials were obtained and were labelled BN/B//2O//3, BN/SiC and Si//3N//4/BN. In addition, a sialon/BN composite was prepared by hot-pressing sialon and BN raw materials at 1800 degree C for 1 h. Specimens suitable for TEM analysis were prepared by the conventional ion-beam milling technique. The excellent thermal shock properties of BN-based material could be related to the microstructures.