Effects of Duty Cycle on Texture Orientation and Composition of TiCx Nanostructured coatings

Nanostructured titanium carbide (TiCx) coatings are deposited on steel substrates by plasma chemical vapor deposition using three different duty cycles of 33, 40, and 50% and characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The relationship between the texture orientation/elemental concentration and duty cycle can be divided into two regimes, carbide (TiCx) state and oxycarbide (TiCxOy) state. The coatings crystallize into a TiC NaCl-type crystal structure (FCC) in the carbide and oxycarbide states and a smaller “x” in the TiCx coatings causes the transformation of the preferred orientation of (200) in the carbide state to (111) in the oxycarbide state. A poorly crystallized anatase phase is also observed from the coatings deposited using duty cycles of 40 and 50% and this anatase phase is detected from the oxycarbide state.