Research On Micro-structure And Properties Of Tin-based Film Prepared By PVD

By the addition of aluminum and silicon element to the Ti target respectively,the Ti-Al-N and Ti-Si-N films were deposited on the W₆Mo₅Cr₄V₂ high-speed steel using multi-arc ion plating technique.-hollow cathode electron beam assisted deposition situation.The composition of phases and element of the films were determined by x-ray diffraction,scanning electron microscope,energy dispersive spectroscopy and transmission electron microscope.The surface roughness was characteried by confocal laser scanning microscope.The hardness,elastic modulus,coefficient of friction and the film/substrate adhesion strength were characterized by univeral nano/micro material tester.The character of different deposition methods,the deposition mechanism and the effects of the composition and proportion of the target on phase composition,quality and properties were studied.The results show that:The atomic level clean surface was obtained,due to the hollow cathode electron beam assisted deposition sputter and clean the surface.Meawhile,the substrate will be preheated fully,which improved the deposition and the quality of films.Compared with the multi-arc ion plating,the number of macro-particle was reduced using hollow cathode electron beam assisted deposition,which leads to the better surface quality,the lower surface roughness and excellent film/substrate adhesive strength.The phases of Ti-Si-N film were composed of TiN and Si₃N₄,rather than the ternary phase?TiSiN?,whose results are based on analysis the phases and thermodynamic data of the film.Meanwhile,the content of Si₃N₄ in the film firstly increases and then decreases with the increasing of Si wt%in the target,due to the structure of Si is stable,and not easy to ionize.The film produced by 15%Si target shows the most excellent performance,such as maximum film/substrate adhesive strength?43.5N?,minimum surface roughness?0.476?m?,friction coefficient?0.76?,excellent hardness?34.8GPa?and elastic modulus?333.2GPa?.On the other hand,The ternary phase?Ti₃AlN?was formed,due to Al dissolved into the TiN lattice,and formed the replacement style solid solution in the Ti-Al-N film,the hardness 44.0GPa,the surface roughness 0.888?m,the friction coefficient 0.73 and the film/substrate adhesive strength 33.5N could be obtained.The columnar grains were formed for its preferred orientation.The solution strengthening leads to the higher hardness.Meanwhile,the stress was produced for the lattice distortion.Even if pre-depositing the TiN transition layer,the film/substrate adhesion strength of the Ti-Al-N film is lower than that of the Ti-Si-N film which without depositing.However,the microstructure of TiN was refined,its preferred orientation was improved and the fine-grain strengthening was produced for the formation of Si₃N₄,which leads to the lowest surface roughness and excellent film/substrate adhesive strength without pre-depositing the TiN transition layer in the Ti-Si-N film,which provided a basis for the Ti-Si-N film without pre-depositing the transition layer.Meanwhile,the process was simplified.At the same time,Compared with the Ti-Al-N and TiN films,the Si₃N₄ with self-lubricating was formed in the Ti-Si-N film,which leads to higher wetting angle up to 83.96�.Therefore,the film has better adhesion resistance,which could significantly improve the cutting process of�sticking phenomenon�.