| Aluminum and aluminum alloys are widely used in the fields of energy,transportation,electronics,construction and defense industries due to their excellent performance.In addition,with the worse service environment of aluminum alloys,owning to low surface hardness,poor wear resistance,serious abrasion usually happened on the surface with using and thus restricts their wider applications.In recent years,in order to adapt to various situations,the investigation on the surface modification of aluminum alloys and improvemente of the surface properties of aluminum alloy has became more and more importante.Among various surface treatment technologies,the magnetic filter cathode vacuum arc technology is widely used becanse of simple equipment,fast deposition rate,uniform and compact film preparation,strong film-based bonding force and wide range of platable materials.In this subject,the?Ti,Al?N film is deposited on the surface of Al-Si alloy with magnetic filter cathode vacuum arc technique.The modification effect of TiAlN film on the surface of aluminum alloy is explored,such as effects of N2 flow rate,substrate negative bias and film structure on the microstructure and properties of TiAlN films.Research indicates:1.When the flow rate of N2 was from 50 sccm to 90 sccm,the TiAlN film was fcc.Regulating the N2 flow rate can effectively inhibit the growth of the columnar crystal structure in the film.As N2 flow rate increased,the microhardness and H3/E*2 of the film raised first and then decreased.When the N2 flow rate was 70sccm,the microhardness and plastic deformation resistance of the film reached the maximum.The TiAlN film has favorable film-based bonding force with different N2 flow rates.The friction coefficient of the film was between 0.430.48,which was less than the friction aluminum alloy coefficient of 0.63.When the flow rate of N2was 70sccm,the wear rate of the sample reached a minimum value of 4.89×10-5[mm3/Nm].Compared to wear rate of the aluminum alloy of 3.08×10-4[mm3/Nm],the value of this subject was reduced with an order of magnitude.TiAlN film can improve effectively the wear resistance of the aluminum alloy matrix.2.When the negative bias voltage was between 50V and 100V,the thickness of the film increased first and then decreased with the increase of the negative bias voltage.The roughness of the film diminished first and then increased gradually and there is not coarse columnar crystal structure in the film.When the N2 flow rate was 70 sccm and the negative bias voltage was 75V,the microhardness and plastic deformation resistance of the single-layer TiAlN film reached the maximum and the wear rate was minimized.3.The multi-layer structure inhibited effectively the growth of TiAlN film grains.Then the grain was refined,structure was more compact,the mechanical properties were improved,and the microhardness and plastic deformation resistance of the film reach a maximum of 30.81GPa and 0.576.The film-based bonding force of the multilayer structure and the gradient structure TiAlN film was significantly enhance,the bonding force level is HF1,and the critical load Lc2 was 13.40 N and 11.78 N.The wear rate of the multilayer structure and the gradient structure TiAlN film was reduced by two orders of magnitude compared to the aluminum alloy. |
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