The kinetics of the CVD of boron nitride from trimethoxyborane (TMOB) and ammonia (NH 3 ) under atmospheric pressure was investigated by varying the following process parameters: temperature, residence time of the reactants, molar fraction of TMOB, and the NH 3 /TMOB ratio, c. A kinetic power law equation was derived, that describes the experimental results with good accuracy. The reaction order with respect to TMOB is found to be 0.9 and ± 0.2 with respect to NH 3 . Between 800 C and 950 C, the deposition rate is controlled by the surface reaction kinetics with apparent activation energy of 115.1 kJ mol ±1 . The deposited BN films were characterized by IR spectroscopy, Raman spectroscopy, and X-ray diffraction (XRD). The microstructure of the deposits depends on the nature of the substrates used. Turbostratic boron nitride (t-BN) was deposited on graphite, and hexagonal boron nitride (h-BN) on alumina substrates. X-ray photoelectron spectroscopy (XPS) analyses show nearly stoichiometric BN films for deposition temperatures in the range 850±950 C for high amounts of ammonia (100 < c < 150) in the feed gas.

Chemical Vapor Aluminizing (CVA) is used for more than 20 years to protect blades and vanes in the hot section of aero- and land based turbines against oxidation and hot corrosion [1]. Modern CVA is an advanced process capable of controlled alloying the coating with additional elements using metal chlorides and tight control of the coating composition. CVA processes offer a number of advantages over conventional pack and above-the-pack cementation. This paper deals with the industrial CVA technology to produce multi-component coatings using different metal chloride generating devices. Specific examples illustrate the influence of the coating parameters and base materials on the NiAl-based coatings microstructure and composition. Advanced co-deposition CVA processes with addition of different metal elements to the aluminide coatings are presented. Modified coating properties and structures of multiple metal coatings with elements like Al, Cr, Si, Co, Y and others will be discussed.