Study Of The Film On Aluminum Alloy Wheel By Magnetron Sputtering Process

At present, the surface treatment modes of aluminum alloy wheels mainly havepainting, plating and magnetron sputtering. The films of aluminum alloy wheels preparedby spraying process have low hardness, poor wear resistance and poor color brightness,besides it will cause air pollution in the process of paint drying. In the electroplatingaluminum alloy wheels process, plating solution contain hexavalent chromium, nickel,cadmium and other harmful elements, and the waste solution will cause waterpollution.The films of aluminum alloy wheels prepared by magnetron sputtering processhave outstanding performance such as corrosion resistance, abrasion resistance, etc.Besides the process of magnetron sputtering have no pollution about environmental.However, now the color of films prepared by magnetron sputtering is single. And in theprepared process of films, there are many problems such as leakage plating, poor adhesionstrength. It is the problem that urgent to be studied that using magnetron sputtering toprepare multi-color system, decorative and qualified films on the surface of aluminumalloy wheels.It is the urgent problem that prepared performance standards colorful and decorativefilms using magnetron sputtering technology.In this study, we use the different colors matrix compound thin film which preparedon the surface of aluminum alloy wheels with media paint as the object and advancedintermediate frequency unbalanced reactive magnetron sputtering as the method. And weget the optimal craft and parameters of the preparation of color compound thin films.In this study, we study the effects of glow discharge cleaning, the mainbombardment, substrate temperature, and other process parameters on the binding forceof the film and base and the uniformity of the sputtering thin film. The results show thatcompound thin film sputtering directly on the medium paint rather than on the pure metaland films will produce leakage plated phenomenon. Some of the pure metal film (such aspure Zr) can not be combined with the medium paint. Combined the technology of multi-arc ion plating and sputter ion plating, we deposited multi-layer composite films on thesurface of wheels. The process is as follow: the first step is that depositing a layer of puremetal transition layer on the surface of wheels by multi-arc ion plating technology, toensure the binding force of the film and wheels, the second step is that depositing a layer of metal compound thin film on the transition layer by frequency magnetron sputteringtechnique to solve the technical problems existing in the direct deposition such as leakagegenerated, cracking, adhesion strength difference as well as coloring difficultly.By studying the technology that using medium frequency magnetron sputtering forpreparing gold yellow Al/ZrN composite film, we analysis the effects of reactive gas flowand sputtering time on the chroma of ZrN film and get the final process parameters ofpreparation of Al/ZrN composite films: the nitrogen flow rate of15sccm, the sputteringtime of3min. Meanwhile we test the adhesion, corrosion resistance, heat resistance, filmhardness and other national predetermined performance of the films. The test results satisfythe requirements of the decorative films of the wheels.By adjusting the metal material and parameters of the sputtering, we can depositseveral color composite films on the surface of the wheels: silver-white of Cr/CrN, redroses of Al/ZrCN, black of Al/ZrC. Different color film meet the need of thediversification, fashion and personalized of the car wheels.In the plating film vacuum chamber a wheel hub rotation and revolution chuckingmechanism has been designed. The technical problem that the wheel can’t be uniformlyplated because the rim was obscured by the flange during the sputtering process has beensolved by this way.To sum up, this paper has reached the process and parameters of sputtering Colorcompound thin film on the hub surface, the problem of missing plating film, poorinterfacial adhesion and thin films from cracked has been solved, and a thin film witchmeets the national standard has been prepared, and which available for industrialproduction.