Investigation of thin titanium carbonitride coatings deposited onto stainless steel

Titanium carbonitride (TiCN) coatings are commonly used in a variety of applications, from microelectronics to high-performance cutting tools. The TiCN coatings grown by chemical vapor deposition are especially attractive because this technique provides a very high degree of control during the procedure. A gas-phase deposition utilizing an organometallic precursor molecule, tetrakis-dimethylamino-titanium was used to grow thin TiCN coatings onto 4140 series steel prepared and cleaned in vacuum. A highly controlled conformal filling was achieved by the deposition performed onto a sputter-cleaned steel surface held at 600 K. The film of the overall Ti:C:N composition of 1:1:1 was produced, as demonstrated by Auger electron spectroscopy. In air, these coatings are oxidized but maintain their uniformity, as demonstrated by time-of-flight secondary ion mass spectrometry. The chemical state of the elements in the coatings was investigated by the X-ray photoelectron spectroscopy and the morphology of the films produced was investigated by atomic force microscopy. Finally, the initial mechanical testing of the films was performed by comparing Young's modulus to that of the underlying steel.

► TiCN film was deposited by chemical vapor deposition onto a steel substrate.
► The film is comprised of Ti, C, and N and is partially oxidized.
► The depth-profiling studies confirmed that the film is uniform in thickness.
► Microscopy investigation showed a sharp interface between the coating and substrate.
► The topography of coated and uncoated samples is very different.