Study of Grain Boundary Structure of Ceramics by Electron Backscattered Diffraction (EBSD) Analyses

It is important to analyze the grain boundary structure because the crystallographic orientation of one grain matches the orientation of neighboring grains during the sintering process. In the present work, the in situ silicon nitride (Si3N4) composite is analyzed by the electron backscattered diffraction (EBSD) method using field emission-scanning electron microscopy (FE-SEM: JSM-6330F, JEOL) with an orientation imaging microscopy analysis device (TSL, Inc.). The following results were obtained: 1) Si3N4 ceramics of hexagonal structure was successfully analyzed by the EBSD method. 2) Elongated Si3N4 particles grew vertically in the alignment direction of seed grains. 3) Growth direction and side planes of the elongated Si3N4 particles are influenced by alignment of seed grains and the hot pressing pressure. 4) It is important to analyze microstructure during the sintering stage in order to improve thermal conductivity and mechanical properties of in situ Si3N4 composite.