Task 6.7.3 - Interfacial Mass Transport Effects in Composite Materials

A series of TiNX and Ti(N,O)X films formed from a TiC, N2, H2, and (N2 + 02 ) gas mixture was deposited on aluminum ceramics at 1073 K for 5 hr at atmospheric pressure, according to the procedure described in Dekker et al. These conditions were selected because they offer a reasonable deposition rate and low chlorine content in films. The TiNX films, with two different nonstoichiometries controlled by the ratio of to H2 and two Ti(N,O)X films with different nitrogen and oxygen content were prepared. The N2 and H2 gases were first purified in alkaline pyrogallol and dried over silica gel and further over a copper and palladium catalyst. TiCld concentration in flowing N2 and H2 (70/30) corresponded to its vapor pressure over liquid at 300 K. Film thickness was determined using a multiple interferometer. All of the films obtained were thicker than 1000 nm. Phase analysis and interatomic distances were determined by x-ray diffraction analysis (XRD) at room temperature