| TiAlN as a high hardness,a high-temperature oxidation resistance(800℃) and a high thermal stability(1470 ℃) is widely used in the high-speed cutting and molding manufacturing processes which has been replaced Ti N in the traditional hard thin film.Besides,Copper as a perfect plasticity and ductility is always used in the thin film to enhance the mechanical properties of thin film.So to improve the mechanics properties of Ti Al N thin film,this research was deposited the different thickness of the copper layer in the Ti Al N thin film to study and explore what the effection of the copper layer in the Ti Al N-Cu multilayer film and if it also could improve the hardness,adhension,toughness and abrasive resistance of the Ti Al N-Cu multilayer film compared the simple Ti Al N thin film.As well,to reveal the hardness and toughness mechanism of multi-layer film,the research is theoratically analyzed the mechanics properties and the friction and wear properties of the different-thickness copper layer of Ti Al N-Cu multilayer film.The experiment was used BY-DH-4A type multi-arc ion plating to deposit the thin film.Firstly it was tested the best parameter of this arc ion plating machine to deposite Ti Al N thin film.In addition,it was deposited a transition layert Ti Al to improve the adhension between the film and substrate.Ti Al N-Cu multilayer film was deposited in-100 V pulsed bias with the 30% duty ratio and the current of the Ti Al target and Cu target was 90 A.Ti Al N layer was deposited in N2 condition and the the work pressure was 0.5Pa,Copper interlayer and Ti Al transition layer were deposited in Ar condition and the work pressure was 0.3Pa.According the research,it is analyzed the structure of multilayer is one of the most important factor to impact the mechanics properties of the film just like the residual stress,the hardness,the adhension,et.It is indicated when the thickness of copper layer is to 81 nm,the mechanics of the Ti Al N-Cu multilayer film is the highest in this experiment,when the thickness of copper layer is more than 81 nm,the mechanics of Ti Al N-Cu multilayer film rapidly decline which drop under the Ti Al N thin film.According to the effection of nanostructure it is known that the modulated wavelength(λ) is in the nanostructure,the intensity of material will not obey the Hall-Petch,it will up to the peak and along the thickness increase,it will rapidly decrease;when the modulated wavelength is in the microstructure,the intensity of material obey the Hall-Petch.Thus the mechanical propoties of the film are partly determined by the thickness of copper layer.The experiment also analyze that the ductility and adhension of Ti Al N-Cu multilayer film are higher than the Ti Al N thin film.In addition,it is tested and calculated the critical value of surface roughness is 0.12μm which is according with the research of the Svahn.It is indicated that when the value is under the critical value,the surface roughness will not much affect the friction coefficient,on the contrary it will much affect.Besides the experiment analyze the friction and wear propoties of the Ti Al N thin film and Ti Al N-Cu multilayer film.The research indicate the different thickness of copper layer determine the different adhension and the different type of the wear.When the thickness of copper layer is more than 108 nm,the wear rate of Ti Al N-Cu multilayer film is less than the wear rate of Ti Al N thin film as well as shows that the wear resistance is much better than Ti Al N thin film.The highest bonding stress of Ti Al N-Cu multilayer film corresponds the lowest hardness,friction coefficient and wear rate corresponding adhesive wear; the middle of the bonding stress of Ti Al N-Cu multilayer film corresponds fatigue wear;the lowest bonding stress of Ti Al N-Cu multilayer film corresponds the highest hardness,friction coefficient and wear rate corresponding abrasive wear.However Ti Al N thin film corresponds not only adhesive wear but also abrasive wear due to its lowest bonding stress in the experiment and a higher hardness of the thin film’s surface,so the spalling and Ti Al N debrises on the surface will occure.According this experiment explored and analyzed,it is showed that a priority thickness of copper layer will improve the mechanical properties of the simple Ti Al N thin film.When the thickness of copper layer is in the nano size,the hardness of the Ti Al N-Cu multilayer film will increase.When the thickness of copper layer is in the size of 100 nm,the bonding stress and wear resistance are much better than the Ti Al N thin film.This research has a further usage and reference value in the practical manufactory and mechanical. |
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