HIGH-RESOLUTION ELECTRON-MICROSCOPY OBSERVATION OF INTERFACIAL STRUCTURES IN NIAL-MATRIX IN-SITU COMPOSITES REINFORCED BY TIC PARTICULATES

The structures of interfaces in NiAl-matrix in situ composites reinfor ced by TiC particulates were studied by means of high-resolution elect ron microscopy (HREM). No consistent orientation relationship between TiC particles and the NiAl matrix was found. In most cases, TiC partic les bonded well to the NiAl matrix free from any interfacial phases. H owever, in some cases, an interfacial amorphous layer with a thickness of about 3 nm was found. The annealed NiAl-TiC composite showed a goo d chemical compatibility between the TiC particles and the NiAl matrix , though, some interfacial layers between TiC and NiAl, which were det ermined to be C-deficient TiC, were found. NiAl precipitates were obse rved in the TiC particles of the annealed specimens.