Research On Fabrication Of Flexible Cathode For Surface Texture Of Electrochemical Machining

Micro Electrochemical machining(Electrochemical micromachining,ECMM)is based on the principle of Electrochemical anodic dissolution,in the form of ion removal in material,is a kind of potential surface texture processing technology.In this paper,a scheme of flexible cathode electrochemical machining is presented on the basis of maskless electrochemical machining.Based on laser direct write wiring technology,the conductive pattern structure is generated on the flexible substrate and the flexible cathode is prepared.The flexible cathode can be made and used for many times.According to the different processed workpiece,the suitable tooling fixture can be printed by 3D printing technology to realize the electrochemical machining on the free surface.Laser Direct Write wiring technology is a new type of circuit board wiring technology,which use the high energy density of laser beam to conduct light and heat reaction with the substrate coating to form a conductive structure on the substrate surface.In combination with 3D printing technology,the flow channel and gap required in electrochemical machining are integrated into shape,and then the copper plating process is used to obtain the integrated flexible electrode.Use this method to make the flexible cathode has advantages of high efficiency,low cost,to flow through the 3D printing technology and machining gap directly print out the traditional processing way is not easy to processing molding can design complex flow channel,at the same time guarantee the uniformity of the machining gap and the rationality of the electrolyte flow field distribution,improve the electrochemical machining replication precision.In this paper,according to the design of the flexible cathode preparation scheme,the laser direct writing platform and the electrochemical machining test platform were built,and the experimental study on the surface texture of the flexible cathode electrochemical machining was carried out.The ultraviolet pulse laser with the wavelength of 355 nm is adopted,and the spot diameter was about 10 ?m.The electrochemical machining platform is composed of machine body,pulse power supply and electrolyte update system.According to the working principle of laser-activated electroless copper plating and laser direct writing technology,two kinds of flexible cathode preparation processes were studied: molecular precursor method(MPM).EDTA-Cu and Cu(CH3COO)2H2O were used as copper source to prepare active films by spinning.Using XPS,XAES,TGA(thermo gravimetric analyzer),XRD(X-ray diffraction analysis)and other instruments to explore the laser direct writing mechanism of precursor films.The experimental results showed that after laser activation of EDTA-Cu,the presence of Cu+ in the activated region was confirmed by XPS and AES,which acted as the catalytic core in electroless copper plating.The 3D printing technology was used to prepare the flexible negative substrate,and the confirmatory electrochemical machining experiment was carried out.The groove depth and width were about 2 ?m and 200 ?m respectively.On the other hand,the precursor film with Cu(CH3COO)2H2O as the copper source was thermally decomposed under the action of laser light and heat,and finally generated copper elemental substance.The conductive structure was obtained on the surface of PI substrate.The 3D printing technology was used to prepare the integrated flexible cathode,and the electrochemical machining surface groove test was carried out on the inner wall of cylinder liner parts.Choose a group of appropriate electrochemical machining process parameters and process out a mesh groove with clear grain.The depth of the groove was about 23 ?m,and the width of the groove was about 1.55 mm.The results show that the flexible cathode based on 3D printing and laser direct write wiring technology is feasible for surface texture electrochemical machining of plane and cylinder inner wall.