Study On Preparation And Properties Of Ti-Si Multielement Multilayer DLC Coating

Diamond-like carbon(DLC)films are widely used in the field of solid lubrication protection due to their high hardness,excellent friction and wear performance,and good chemical stability and corrosion resistance.However,problems such as high internal stress and poor environmental adaptability have to be the bottlenecks hindering the application of DLC films in extreme working conditions.In this paper,magnetron sputtering with ion beam technology was used to prepare DLC films by changing the parameters of bias,Ar gas flow and C target current.The influence of the parameters on the mechanical properties and tribological properties of DLC films was investigated,and the relationship between the parameters and the mechanical properties and tribological properties of DLC films was established.On the basis of parameters optimizing,different Ti and Si contents were doped into Ti-DLC films and Si-DLC films by changing the Ti and Si targets current.The microstructure and surface morphology of Ti-DLC films and Si-DLC films were characterized by XRD,Raman,SEM and AFM,and the effects of mechanical properties and tribological properties of the films were investigated by nano-indentation instrument,scratch meter and CSM ball-disk friction and wear tester.The results show that,the content of sp~3 bond in DLC film can be effectively improved by doped Ti.Meanwhile,the internal stress in the film can be released by the interface of TiC nanocrystalline,so as to ensure that the hardness of the film is not sacrificed with the internal stress reducing and obtains satisfying H/E values,friction coefficient and wear rate.However,when the Ti target current is high,the Ti element in the film reacts with O element to produce titanium oxide particles,which may destroy the transfer film and leads to transfer film destruction during friction process.The current of Si target also has an important effect on the mechanical properties and tribological properties of Si-DLC films.The results show that Si-DLC films with low internal stress and high hardness can be obtained with small Si target current.However,the surface roughness of DLC film can be increased rapidly with the elasticity recovery ability worsen when the current of Si target is high.Moreover,the tribological properties of Si-DLC films also decreases sharply in this process.In order to improve the humidity adaptability of DLC films,Ti-DLC/Si-DLC multilayer films with different modulation ratios were prepared,and the effect of humidity on the tribological properties of the multilayer films was investigated.The results show that the tribological properties and humidity adaptability of multilayer Ti-DLC/Si-DLC films can be effectively improved by adjusting the deposition time of Si-DLC film.