Titanium carbonitrides obtained by chemical vapor deposition

This study is a preliminary investigation of hard abrasion-resistant coatings obtained by the chemical vapor deposition of titanium carbonitrides with the objectives of (1) developing a process with an upper temperature limit of 650 °C to avoid altering the properties of substrates such as steel and (2) establishing a relation between the properties of the coatings and the deposition parameters. By using amines as a source of carbon and nitrogen, uniform and adherent coatings were obtained at deposition temperatures of 550 °C to 650 °C, provided the steel substrate was electroplated with nickel or cobalt to prevent the formation of interfacial iron chlorides. X-ray diffraction showed that the lattice parameter of the coatings deposited with trimethylamine increased with higher deposition temperatures with a corresponding increase in the carbide mole per cent, which rose from 25% at 550 °C to 72% at 650 °C. The lattice parameter and the carbide mole per cent were higher with trimethylamine than with dimethylamine (53% and 30%, respectively, at 600 °C).