Effects of Interlayers on Tribological Property of Diamond-Like Carbon Multilayer Films on TC4 Titanium Alloy

The deposition of diamond-like (DLC) films on a titanium alloy (TC4) surface is an effective method to improve its wear resistance and service life. The soft/hard DLC multilayer film and DLC multilayer films with two different interlayers (Ti and Ti/TiC) were deposited on titanium alloys by filtered cathodic vacuum arc technology. The structure and surface morphology of the multilayer films were analyzed by using scanning electron microscopy (SEM) and optical microscope. The residual stress, hardness, adhesive force, and wear properties were evaluated using the nano-indenter, film stress tester, scratch tester, and wear test, respectively. The results show that the DLC multilayer films have lower compressive stress than the monolithic hard DLC film, and the residual stress decreased from 12.63 GPa to 6.21 GPa. The DLC multilayer film with Ti/TiC interlayer has the lowest compressive stress and the best adhesion strength. The wear resistance and hardness of the DLC multilayer film with Ti/TiC interlayer were significantly improved. The results provide technical reference and theoretical basis for the preparation and application of high-hard wear resistance DLC multilayer film on titanium alloy.