Oxidation behavior of Ti-B-C-N coatings deposited by reactive magnetron sputtering

► Ti-B-C-N coatings fabricated by RMS possess a nano-composite structure. ► The Ti-B-C-N coatings with 28.9 at.% C are stable below 700 °C in air. ► Carbon addition leads to the oxidation resistance of the coatings decrease. ► The nc-Ti(C, N) are oxidized as the oxidize temperature increase to 600 °C. ► The oxidation of the coatings and nc-Ti(C, N) are controlled by oxygen diffusion.