HREM STUDY OF TIB2 NIAL INTERFACES IN A NIAL-TIB2 IN-SITU COMPOSITE/

The TiB2/NiAl interfaces in reactive hot-pressing (RHP) processed NiAl -20 vol% TiB2 in-situ composites were studied by means of high-resolut ion electron microscopy (HREM) including image simulation. There is no consistent orientation relationship between TiB2 particles and the Ni Al matrix. In most cases, the TiB2/NiAl interfaces are atomically flat , sharp and free from any interfacial phase. Atomic configuration at t he TiB2/NiAl interface was investigated. A thin interfacial amorphous layer between TiB2 and NiAl could be observed in some cases, which may act as a stress absorber. It was also observed that a thin interfacia l phase which is still undetermined may exist at the TiB2/NiAl interfa ce.