Microstructure And Properties Of TiAlVN Coatings Deposited By Unbalance Magnetron Sputtering

Reasonable development of marine resources can effectively improve the increasingly serious energy problem.However,the marine environment is highly corrosive,and metal equipment is easy to fail in this environment.It is an effective way to improve the comprehensive performance of metal substrate and prolong the service life of workpiece to prepare a nitride protective coating on the surface of metal substrate by physical vapor deposition.Multicomponent nanocomposite coating has many advantages,which is the research hotspots and development direction of hard coating.TiAlVN multicomponent nanocomposite coatings were prepared by unbalanced magnetron sputtering.The effects of V content on microstructure,crystal structure,chemical composition,microhardness,Young’s modulus,bonding force and corrosion resistance of the coatings in 3.5%Na Cl solution were systematically studied.In addition,the microstructure and properties of the coating under different TiAlV alloy target powers were also studied.TiAlVN coatings with different V content were prepared by controlling V target power in multi-target sputtering mode.The results show that TiAlVN coating has island morphology and Na Cl fcc structure.The V content in the coating increases with the increase of V target power.With the increase of V content,the（111）crystal plane preferred orientation,the diffraction peak shifted to the right first and then to the left,the surface pores of the coating decreased,the structure became more compact,and the surface roughness of the coating decreased first and then increased.The hardness,Young’s modulus and bonding force of TiAlVN coating increase first and then decrease with the increase of V content.When V content is 20.2 at.%,the mechanical properties of TiAlVN coating are the best,which are 22 GPa,308.8 GPa and 35 N,respectively.Compared with the coating without V doping,the coating with V doping has better corrosion resistance.With the increase of V content,the corrosion potential,low frequency impedance and charge transfer resistance of TiAlVN coating increase first and then decrease,while the corrosion current density decreases first and then increases.When the V content is 20.2 at.%,the maximum corrosion potential（–0.261 V）,low frequency impedance（56700Ω·cm²）,charge transfer resistance（1.71×10⁵Ω·cm²）and minimum corrosion current density（0.487μA/cm²）are obtained.The TiAlVN coating has the best corrosion resistance at this time.Four kinds of TiAlVN coatings were fabricated by controlling TiAlV alloy target power.The results show that the TiAlVN coatings is a co-existence structure of the face centered cubic and hexagonal.With the increase of target power,the Al content in the coating increases slightly,the content of Ti and V decrease a little,the intensity of the diffraction peak of Ti₂N（111）decreases gradually,and shifts to a small angle,the coating structure is compact and the thickness increases.The surface roughness of the coating increases first,then decreases slightly and then increases.With the increase of target power,the hardness of the coating first increases and then decreases,while the Young’s modulus of the coating increases and the bonding force of the coating decreases,and the TiAlVN coating acquired at 450 W shows the best comprehensive mechanical properties,and the values are 41.9 GPa,372.8 GPa and15.5 N,respectively.With the increase of target power,the corrosion potential,low frequency impedance and charge transfer resistance of TiAlVN coating increase first and then decrease,while the corrosion current density and corrosion rate are decrease first and then increase.When the target power is 450 W,the maximum corrosion potential（–0.2018 V）,low frequency impedance（215000Ω·cm²）and charge transfer resistance（3.047×10⁶Ω·cm²）,as well as the minimum corrosion current density（0.1454μA/cm²）and corrosion rate（3.32239μm/year）are obtained.At this time,TiAlVN coating has the strongest corrosion resistance.