Abstract: The surface properties Of Ti-6Al-4V alloy coated with titanium nitride, TIN + TiC + Ti(C,N)/DLC, TIN/DLC, and TI C/DLC films by plasma-based ion implantation (PBII) with nitrogen, PBH with nitrogen then acetylene, PBII with nitrogen then glow discharge deposition with acetylene plus hydrogen, and PBH with acetylene then glow discharge deposition with acetylene plus hydrogen, respectively, are compared (DLC: diamond like carbon). The corresponding films are found getting dimmer: light gold or gold, smoky color (uneven), light red in black (uneven), and graphite black. and the corresponding film resistivities are about: (1. 0--3. 3) x 10~7, (0. 05- 2. 00) x 10~11 ) (0.016-2.400)× 10~11, and (0.45-1.01)x 10~11 Ω/cm, respectively. Antioxidation ability of the titanium nitride film is poor while existence of carbon (or carbide) improves the antioxidation ability of the films. Having underpone excellent intermediate transitional region of nitrogen and carbon implantation, the top DLC layer of the TIN+TIC+Ti(C,N)/DLC multilayer formed after the carbon implantation has the best adhesion with the substrate among all the multilayers presented. Although microhardness of the samples increases in the order of coatings of titanium nitride, TIN/DLC, TiN+TiC+Ti(C,N)/DLC, and TiC/DLC, the TIN/DLC and TiC/DLC multilayers have greater brittleness compared with other films presented.

Key words: Ti-6Al-4V, nitride, diamond like carbon (DLC), plasma-based ion implantation, microhardness