Titanium Oxynitriding by Plasma-Assisted Thermochemical Treatments Using a Competitive Atmosphere of H2-N2-O2

The incorporation of oxygen and/or nitrogen into the titanium lattice has garnered significant attention due to the broad spectrum of intermediate properties that can be achieved between TiN and TiO2. This article delves into the investigation of surface modification of titanium through plasma-assisted thermochemical treatments employing H2-N2-O2 mixtures. The flow rate of the reducing gas (H2) remained constant at 24 sccm, while the flow rates of N2 and O2 were adjusted to yield a total flow rate of 60 sccm. Analysis using GIXRD, Raman spectroscopy, and XPS demonstrated that TiN exhibits stability exclusively in an oxygen-free atmosphere, while TiO2, in contrast, necessitates an oxygen flux equal to or exceeding 18 sccm for stability. Furthermore, it was found that the presence of nitrogen in the plasma atmosphere resulted in a greater expansion of the α-titanium lattice, although the solubility of interstitials decreased. These findings highlight the potential for a controlled approach to producing solid solutions or titanium oxynitrides.