Si-DLC films deposited by a novel method equipped with a co-potential auxiliary cathode for anti-corrosion and anti-wear application

A novel DLC film deposition method was proposed to realize the deposition of DLC film on the surface of complex shaped workpiece.Meanwhile,Si-DLC film was deposited on the surface of M2 high-speed steel(HSS M2)and 304 stainless steel(304SS),and the microstructure,surface roughness,mechanical properties,corrosion resistance and tribological properties of Si-DLC films were characterized in detail.Results show that Si-DLC film at different axial positions of the auxiliary cathode possesses similar microstructure,film thickness and surface roughness,and the as-deposited Si-DLC film shows the low intrinsic stress of<0.3 GPa.Compared with the 304SS substrate,the Si-DLC film presents more noble corrosion potential,lower corrosion current density and higher polarization resistance,exhibiting higher corrosion resistance.Moreover,the Si-DLC film exhibits higher hardness,elastic factor and plastic factor than HSS M2 substrate and the corresponding adhesive strength is more than 10 N.The Si-DLC film sliding against GCr15 steel ball shows a lower friction coefficient than that of HSS M2 substrate and the wear rate of GCr15 steel ball sliding against the Si-DLC is lower than that of HSS M2 substrate.In addition,this novel method was used to deposit Si-DLC film on gears,drills and bearings without rotating sample racks.As a consequence,this method possesses great potential and can be generalized for the deposition of DLC film on the surface of complex shape workpiece.