| In this paper,TC4 titanium alloy is the main research object.Firstly,the interaction between electrochemical corrosion and mechanical wear of TC4 titanium alloy was studied in simulated seawater,the effects of different electrochemical states on the corrosion and wear behavior of TC4 titanium alloy were investigated.Secondly,Si-DLC film was prepared on the surface of TC4 titanium alloy by plasma enhanced chemical vapor deposition?PECVD?.The effect of Si content on the structure,composition and mechanical properties of DLC films was investigated by SEM,XPS,Raman,nanoindentation and scratch methods.The friction and corrosion properties of Si-DLC films were studied by methods of friction,electrochemical test and friction corrosion interactive test in simulated seawater.Finally,different thickness?Six-DLC/Siy-DLC?n films?x,y are the Si content,n is the period?deposited on TC4titanium alloy were prepared by PECVD.The effect of thickness on the structure,composition,mechanical properties and frictional corrosion properties of the film was investigated.under different electrochemical conditions.The friction and corrosion interaction of 34?m?Six-DLC/Siy-DLC?600 films was investigated.The main conclusions are as follows:?1?The interaction between electrochemical corrosion and mechanical wear for TC4 titanium alloy in simulated seawater shows that:The self-corrosion potential of TC4 titanium alloy is-0.40 V.In the friction corrosion process,the self-corrosion potential of TC4 titanium alloy is negatively offset?-0.65 V?,corrosion current is as increases as the applied potential,and the lowest friction coefficient of TC4 titanium alloy is obtained when the potential is at OCP.The fact that the loss of TC4 titanium alloy volume increases along with the increase of the applied potential,confirms that the interaction of corrosion and wear is enhanced along with the increase of the applied potential.When the potential increases from-0.5 V to 0.8 V,the material loss caused by the interaction of corrosion and wear increases from 12%to 66%,and the loss caused by corrosion-induced wear increases from 7%to 44%.Under the condition of OCP and below the applied potential,the wear mechanism of TC4titanium alloy is abrasive wear;The wear mechanism of TC4 titanium alloy at 0 V potential is abrasive wear and fatigue wear;The wear mechanism of TC4 titanium alloy at 0.8 V potential is abrasive wear and friction-induced corrosion wear.?2?Studies on Si-DLC film deposited on the surface of titanium alloy shows that:as the Si content increases,the sp3 content in the Si-DLC film increases,and the hardness first increases and then decreases.When the Si content is 11.3 at.%,the hardness of the Si-DLC film has a maximum value?12.6 GP?.The open circuit potential of Si-DLC film increases with the increase of Si content,and the self-corrosion potential increases,the corrosion current and the film void ratio decrease.The film exhibits the best corrosion and friction corrosion resistance when the Si content is 14.8 at.%.The friction coefficient of Si-DLC film decreases with the increase of Si content,and the wear rate first decreases and then increases.When the Si content is 11.3 at.%,the wear rate of the film is as low as 6.48×10-77 mm3/N·m.The wear rate of the film is related to the mechanical properties in addition to its own friction and corrosion resistance.?3?Studies on multilayer films of different thickness?Six-DLC/Siy-DLC?n deposited on the surface of titanium alloy show that:The hardness and elastic modulus,critical load,and residual stress of the multilayer?Six-DLC/Siy-DLC?n film increase as the thickness increases.At the same time,the open circuit potential of the film increases,the self-corrosion potential increases,and the corrosion current decreases because the multilayer interface design reduces the number of defects in the film.The wear rate of the multilayer?Six-DLC/Siy-DLC?n film increases as the load increases.Under the load of 30 N and 200 r/min,the 34?m?Six-DLC/Siy-DLC?60film has a high load carrying capacity,and the wear rate is only 6.93×10-66 mm3/N·m.Friction and corrosion interactive quantitative research shows that the wear volume of the 34?m?60 Period?film increases as the potential increases.At-1 V,OCP,and 0 V applied potential,the volume loss of the film is dominated by pure mechanical wear.At an applied potential of 0.5 V,the volume loss is dominated by pure mechanical wear and corrosion induced wear. |
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