Study On The Effect Of Preparation Parameters And Metal Doping On Diamond-like Carbon Film Prepared By HiPIMS

Diamond-like carbon(DLC)film is a thin film material with excellent properties such as high hardness,high chemical inertness and high wear resistance.DLC is a promising candidate as protective film and has been applied in many different fields.However,there remain drawbacks to resolve before DLC films are further developed for wider applications,such as high electrical resistivity when used as electrode materials and failure due to high residual stress when used as friction protective films.This study uses the high power impulse magnetron sputtering(Hi PIMS)technology,which is an emerging technology in recent years,to deposit DLC films on 304 stainless steels and single-crystal silicon,and improve the performance of DLC films by adjusting the process parameters(deposition temperature and substrate bias)and metal content of titanium and copper co-doping.Analytical and testing instruments such as scanning electron microscope,Raman spectrometer and electrochemical workstation are used to characterize the composition and structure and comprehensive properties of the films,and to study the mechanism of the influence of different preparation conditions on film performance.The study on the effect of temperature and substrate bias on the properties of diamond-like films shows that when the deposition temperature increases from 100?to 300?,the surface morphology of the film becomes incompact,and the sp² bonded carbon content in the DLC film increases as the film is graphitized.The interfacial contact resistance of the film also decreases and the adhesion strength increases,as well as the hardness and corrosion resistance decrease.When the substrate bias voltage is increased from 0 to-400 V,the surface of the DLC film becomes denser,the sp²/sp³bond ratio of the film first decreases and then increases,and the interfacial contact resistance decreases and the corrosion resistance increases.The DLC film deposited at-400 V bias and 100°C has relatively low contact resistance,the highest hardness and excellent corrosion resistance.The study on the effect of titanium and copper co-doping on the properties of diamond-like films shows that with the increase of metal doping content,the size of particle clusters and defects on the surface of the film increase.With about 10 at.%of Ti doping,Ti C nanocrystals are formed in the DLC film.When the Cu doping content is2.5 at.%,it dissolves in the carbon matrix and Cu crystals are not formed until the Cu doping content reaches 7.1 at.%or higher.The sp²/sp³ bond ratio of the DLC film increases with the increase of the Cu doping content,and as the Cu content increases,the residual stress of the film decreases and the adhesion strength increases.After Ti and Cu are co-doped into the DLC film,the friction coefficient and wear rate have increased due to the formation of hard Ti C grains,but with the increase of Cu doping content,the lubrication effect brought by Cu and the decrease in the internal stress reduce the friction coefficient and wear rate of the DLC film.The best tribological properties are obtained in Ti_9.7Cu_15.8-DLC sample.