| Firstly,diamond-like carbon?DLC?films with different transition layer were prepared on the titanium alloy by using unbalanced magnetron sputtering,and the influence of transition layer on the structure and property of DLC film were investigated.Secondly,the doped Si multilayer DLC films?Six-DLC/Siy-DLC?n?where x and y is the certain content,n is the number of layers?with a thickness of up to 50?m were prepared on the titanium alloy by using plasma enhanced chemical vapor deposition,and the structure,mechanical and tribological properties were investigated.Finally,the super-thick DLC films?Six-DLC/Siy-DLC?n/DLC with the thickness of about 36?m were prepared,and the influence of the number of period?modulation period?and the proportion of thickness?modulation ratio?of Si doped DLC films?Six-DLC and Siy-DLC layers?in fixed thickness on the mechanical and tribological properties were studied.The main conclusions are following:?1?The microstructure of DLC films is not changed by the monolayer transition layers?Cr,Si,Ti?,and Si/DLC films have the lowest internal stress and the highest critical load.With the introduction of gradient transition layer?Cr/CrN,Cr/CrN/CrNC?,the content of sp2 bond of DLC films gradually increases,the internal stress gradually decreases,and the adhesive strength gradually increases.Cr/CrN/CrNC/DLC films have the lowest friction coefficient?0.070.10?and wear rate(1.89±0.15×10-7mm3/N·m).?2?The thickness of?Six-DLC/Siy-DLC?n films has no obvious effect on the structure and hardness,but with the thickness of the film increasing,the internal stress decreases gradually.The?Six-DLC/Siy-DLC?n film with the thickness of 35.43±3.32?m has the lowest friction coefficient?around 0.05?,and the lowest wear rate(1.15±0.63×10-7mm3/N·m).The wear rate of the same thickness?Six-DLC/Siy-DLC?n film decreases and then increases with the increase of load.?3?Compared with?Six-DLC/Siy-DLC?n and?Six-DLC/Siy-DLC?n/DLC multilayer films,the friction coefficient of?Six-DLC/Siy-DLC?n/DLC increases,but the wear rate decreases significantly.For the 36?m super-thick DLC film,the modulation period has no obvious effect on the structure of the?Six-DLC/Siy-DLC?n/DLC films,but does significantly on the mechanical property.With the increase of the modulation period,the internal stress and the hardness of the film decreases gradually,and the critical load increases reaching a maximum of 60.3±1.7N.The modulation ratio also has a significant effect on the mechanical property of?Six-DLC/Siy-DLC?n/DLC films.With the increase of modulation ratio,the proportion of the Six-DLC layer increasing,and the stress and hardness of the films decreases gradually,and the adhesive force increases. |
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