Objective The aim of this study was to observed the influence of deposition time on chromatics during nitrogen-doped diamond like carbon coating（N-DLC） on pure titanium by multi impulse arc plasma plating machine. Methods Applying multi impulse arc plasma plating machine to produce TiN coatings on pure titanium in nitrogen atmosphere, then filming with nitrogen-doped DLC on TiN in methane（10-80 min in every 5 min）. The colors of N -DLC were evaluated in the CIE1976 L*a*b* uniform color scale and Mussell notation. The surface morphology of every specimen was analyzed using scanning electron microscope（SEM） and X-ray photoelectron spectroscopy（ XPS）. Results When changing the time of N-DLC coating deposition, N-DLC surface showed different color. Golden yellow was presented when deposition time was 30 min. SEM showed that crystallization was found in N-DLC coatings, the structure changed from stable to clutter by varying the deposition time. Conclusion The chromatics of N-DLC coatings on pure titanium could get golden yellow when deposition time was 30 min, then the crystallized structure was stable.
