TITANIUM CARBIDE AND TITANIUM CARBONITRIDE OBTAINED BY CHEMICAL-VAPOR-DEPOSITION FROM ORGANOMETALLIC PRECURSOR IN THE RANGE 450-800-DEGREES-C

Titanium carbide coatings have been deposited on steel in a cold wall reactor from titanocene dichloride vaporized in a hydrogen carrier gas . Titanium carbonitride was obtained in the same experimental device b y addition of ammonia in the gas phase. These materials were deposited at atmospheric pressure in the temperature range 450-800-degrees-C wi th appreciable deposition rates. According to the temperature range of vaporization of the solid precursor, the deposition proceeded from th e gaseous species coming either from the direct sublimation of the ini tial molecule or from a vaporization of by-products resulting from its decomposition in the vaporization crucible. These two basic vaporizat ion processes resulted in coatings of different compositions and prope rties. Several characterizations such as thickness of the deposit, sur face morphology, composition, grain size, hardness and adherence were carried out.