| In biological materials,owing to the excellent corrosion resistance,biocompati-bility and mechanical properties,titanium alloy is gradually becoming the preferred material for excellent performance.But the friction coefficient and wear performance of titanium alloy is poor.After its implantation,It is may leading to implant failure when a lot of debris released into the body tissue[1]To overcome these shortcomings,we use TiN film to improve the wear resistance of the surface of titanium and achieve good results.A series of TiN monolayed films,TiN compositioned gradient films and TiN/Ti multilayed films were prepared by reaction magention sputtering on Ti6A14V substrate.The crystal structures,surface morphology and cross-sectional microstruct-ure were investigatedby X-ray diffraction(XRD)and scanning electron microscopy(SEM).Using microhardness tester,nano mechanics test system and automatic coating adhesion scratch tester respectively studied the mechanical properties such as hardness,elastic modulus,and such as bonding strength.Using the contact Angle meter and atomic force microscopy studied the hydrophobic membrane mirror and surface roughness.The friction and wear behavior of the film was studied by using the friction and wear tester.We have studied the Depth relationship between film microstructure,crystal structure,mechanical performance and so on.The main results are as follows:(1)The time when depositing TiN film is short,TiN growth(200)preferred orientation.And to extend the time of TiN deposition,TiN crystal preferred orientation from the(200)to(111).Three types of films have appeared two phases of TiN and Ti.The shorter time of Ti transition layer,atoms of N through the TiN/Ti interface diffusion into the Ti layer,causing TiN0.26 emerged in this phase.The TiN gradient film has a TiN component gradient region.Thus made in the condition which is mainly Ti,Ti4N3_x and TiN three-phase mixed phase.(2)For the TiN single film.When the deposied long time,the columnar crystal is completely formed.Because part of the film has bulky crystal which is easy to form defects,resulting in poor mechanical properties.The microhardness of the multilayer TiN/Ti film is significantly enhanced compared to the single film.The adhesion and microhardness of theTiN/Ti multilayer film are decreased with the increase of the cyclic period,and the friction and wear properties are well.It is possible that the microhardness is higher when Cycle more.But due to the thickness of each layer of TiN thin.It may lead in exfoliate phenomenon.So the two groups of multilayer films with different deposition time of the Ti transition layer,the cycle time is less,and the mechanical properties of the composite better.(3)For the gradually increasing time of TiN film,The microhardness value of the micro hardness increased from 11.0GPa to 20.4GPa,and the maximum microhardness value was twice as high as that of the single TiN film.The adhesion of the films increases first and then decreases,the time difference in the gradient to 4 min for the process of arithmetic progression reached peak.At different times,the hardness value with increasing fade time presented irregular.The friction property changes with the increase of the time of the change.Because of the composition of the TiN gradient film is the changed,it eliminated the Exfoliate phenomenon.In summary,the mechanical properties of a gradient TiN film is better than the multilayer TiN/Ti film and single TiN films.(4)The friction coefficient of TiN film is obviously influenced by the surface roughness.With the increase of the surface roughness,the friction coefficient of film becomes larger and larger.The hydrophobic of TiN film has a certain effect in friction coefficient.better hydrophobicity means has a better drag reduction and a lower friction coefficient.the greater of H/E value,the better the performance of wear. |
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