High‐Resolution Electron Microscopy of Chemically Vapor‐Deposited β‐Si3N4‐TiN Composites

Abstract

Microstructures of Si3N4‐TiN composites prepared by chemical vapor deposition (CVD) were investigated by the multibeam imaging technique using a 1 MV electron microscope. High‐resolution images showed a number of fibrous TIN crystallites dispersed in the matrix of CVD β‐Si3N4. Crystallographic orientation relations between β‐Si3N4 and TiN were determined directly from the observed images in the subcell scale. The fibrous axis of TiN is parallel to the (110) direction of the NaCl structure and lies along the c axis of the hexagonal β‐Si3N4 crystal. Domain boundaries, planar faults, nonplanar faults, and dislocations were found in the CVD β‐Si3N4 matrix near the TiN crystallites. The origin of the structure defects is briefly discussed in connection with the formation of TiN crystallites in the matrix.