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高温合金零件电解加工工装设计【13张CAD图纸+毕业论文】【答辩通过】

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关键词：: 高温合金零件电解加工工装设计全套 cad 图纸毕业论文答辩通过

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摘要

电解加工又称电化学加工，是金属工件在电解液中发生阳极溶解的一种加工过程。电解加工对难加工材料可以以柔克刚，对形状复杂的零件可以一次成型，并以表面质量好、生产率高、无工具损耗、无切削应力等优点，在制造业中发挥着重要作用。论文通过对高温合金零件进行分析，设计出一套电解加工工装。电解加工工装包括阴极的设计计算、流场的设计计算以及零件的定位等。阴极的设计采用等间隙分布的原则，在零件原有尺寸上缩小一定的间隙，来设计阴极。根据不同的加工方式可以有不同的加工间隙，这里取加工间隙为0.5mm。对于流场的设计，根据零件的特点采用侧流式加工，在流场设计时还要确定电解液流速和进口压力。另外，流场的设计要均匀，均匀性是指加工面上各处流量充足、均匀，不发生流线相交和其他流场缺陷——如空穴现象、分离现象等。另外，工装的设计要保证良好的密封性。通过设计电解加工工装加工高温合金零件比机械切削加工省时省力，与机械切削加工相比电解加工的表面质量好，且加工范围广，没有切削应力。

关键词：电解加工;阴极设计;流场；工装

High temperature alloy parts electrochemical machining tooling design

Abstract

Electrochemical machining is also called electrochemical machining, metal wor-

kpiece in the electrolyte is an anodic dissolution process. Electrochemical machining of difficult-to-machine materials can, with parts of complex shape can be a forming, and with good surface quality, high productivity, tool wear, cutting stress, plays an important role in manufacturing. Paper through the analysis of high temperature alloy parts, design a set of electrochemical machining tools. Electrochemical machining fixtures including the design of the cathode flow field calculation, design calculation and the positioning parts. Cathode design based on the principle of distribution of intermittent, reduced a certain gap on the parts in the original size, to design the cat-

hode. According to the different processing methods can have different process- sing clearance, here take machining gap is 0.5 mm. To the design of the flow field, accor- ding to the characteristics of the parts with side flow processing, even when in the flow field design to determine the electrolyte flow rate and inlet pressure. In addition, the design of the flow field to uniform and adequate flow throughout uniformity refers to processing surface, uniform, not line intersect and other defects, such as cavitation flow field and separation phenomenon, etc. In addition, the tooling design to ensure good sealing. Through electrochemical machining tooling design than mechanical machining time, high temperature alloy parts compared with mechanical machining electrolytic machining surface quality is good, and the processing range is wide, no cutting stress.

Key Words: Electrochemical machining; The cathode design; The flow field; tooling

1 绪论1

1.1 电解加工的原理1

1.2 电解加工的特点及分类3

1.3 电解加工的应用及研究现状5

1.4本课题主要研究的目的、意义以及重点和难点6

1.5电解加工的研究方法以及电解加工新技术8

1.6 电解加工的设备以及工艺发展8

2 高温合金零件电解加工阴极的设计与计算10

2.1 电解加工成型规律的研究10

2.2 电解加工阴极设计的方法10

2.3 高温合金零件阴极的设计与计算12

2.4 阴极设计的二维图与三维图15

3 高温合金零件电解加工的流场设计17

3.1电解液的流动形式17

3.2 电解液流速和进口压力的确定18

3.2.1 电解液流速的确定18

3.2.2电解液压力的确定20

3.3 流场均匀性的设计21

4 高温合金零件电解加工工装的设计以及总体工装夹具23

4.1电解加工工装的功能及特殊要求23

4.2高温合金零件阴极的定位与连接24

4.3高温合金零件电解加工底座的设计24

4.4 阴极连接杆的设计25

4.5 电解加工工装的特殊技术要求26

4.6 电解加工的导流和导电方式26

4.7 高温合金零件电解加工的总体设计及工作过程27

5 结论30

5.1 总结30

5.2 体会31

参考文献32

致谢33

毕业设计（论文）知识产权声明34

毕业设计（论文）独创性声明35

1 绪论

1.1 电解加工的原理

电解加工（Electrochemical machining,ECM）作为机械加工的的补充手段走过了半个世纪。电解加工的基本原理是电化学阳极溶解，而这一电化学过程又是建立在电解加工间隙中特定的电场、流场分布的基础上的，故电场理论、流场理论以及电化学阳极溶解理论构成了研究电解加工工艺的三大基础理论。[2]电解加工以其在难切削材料、复杂形状的零件加工中体现出的特殊优点，较好的适应了军事工业中若干重要关键产品的特殊需要，首先成为军工生产中不可缺少的重要手段和关键技术，在工业发达国家中获得了较好的应用效果，而我国则是世界上应用电解加工最多的国家只一。

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内容简介：: 672672Journal of the Ceramic Society of Japan115 10672677 (2007)Paperp b j r q j m bKai KAMADA,?Masaaki TOKUTOMI, Miki INADA, Naoya ENOMOTO and Junichi HOJODepartment of Applied Chemistry, Faculty of Engineering, Kyushu University, 744, Motooka, Nishi-ku, Fukuoka8190395Electrochemical micromachining of a metal plate was performed using a solid polymer electrolyte. The fun-damental electrolysis system was composed of a metal plate?anode?polymer electrolyte?tungsten needle?cathode?, where the contact diameter of the metal?polymer interface was extremely small?a fewmm?. Themetal substrate was electrochemically oxidized and then Mn?ions migrated to the polymer electrolyte. As aresult of the continuous application of a dc voltage to the cell, finer-resolution micromachining?10mm?wasachieved under room-temperature operation as compared with our previous results obtained using a Nab?Al2O3solid electrolyte. Furthermore, the present technique was applicable to many different kinds of metal sub-strates.?Received July 3, 2007; Accepted August 24, 2007?Key-words :Electrochemical micromachining, Solid polymer electrolyte, Anodic dissolution, Anodic oxidation,Microelectrode1.IntroductionMicromachining of solid surfaces is employed for the fabri-cation of various microsystems, such as microsensors, micro-reactors, and microelectrode arrays.1?3?It is believed that amore effective and finer-resolution machining technique willbe required for dense integration of micro-parts in state-of-the-art microsystems. Micromachining of solid surfaces isgenerally carried out by position-selective etching of atomsusing mechanical, physical and chemical techniques. Thechemical technique involves immersion of the workpiece,partly covered with a surface masking layer, in an etchingsolution, upon which the surface exposed to the solution isselectively dissolved. According to the type of substrate, apatterned layer is preferentially etched by the solution. Forinstance, the partly pre-formed SiO2layer on a Si substratedissolves in an aqueous HF solution. The fact that no surfacedistortion or stress is induced in the machined workpiece in thewet chemical process is regarded as a distinct advantage overmechanical or physical?sputtering, laser ablation, etc.?tech-niques.As an extension of chemical etching, electrochemicalmicromachining has been studied widely for conductive sub-strates such as metals and semiconductors.4?6?In this tech-nique, dissolution of the masked workpiece?electrode?isaccelerated by applying an electrical bias to the electrolytesolution. As compared with conventional chemical etching,the electrochemical technique enables a more rapid and well-controlled dissolution rate, and requires no aggressive electro-lytes such as an acid. Since electrochemical micromachiningemploys an electrolyte solution, masking is mandatory forposition-selective etching and the process entails multi steps. Itis difficult to control the aspect ratio and size of a groove aftermicromachining because side etching occurs as a result ofpenetration of liquid under the mask. In order to circumventthese problems, the solid electrochemical method has beenproposed,7?,8?which uses solid ion conductors as an electro-lyte, rather than solutions. That is, electrochemical micro-machining replaces the liquid electrolyte by a solid electrolyte.Our group has reported that the related solid state techniqueinvolves an anodic electrochemical reaction at the microcon-tact between the metal substrate and ion conductor.9?,10?Themetal substrate is locally incorporated into the ion conductorin the form of metal ions via the microcontact under a dc bias.Micromachining can be achieved as a result of consumption ofthe metal only at the microcontact. The proposed techniquehas many advantages over other conventional electrochemicalmicromachining techniques:?1?no liquid electrolytes, whichare difficult to handle, are required, and?2?direct structuringcan be achieved without any pretreatments such as masking orcoating. Of course, the advantages of the conventional tech-nique, including simplicity of the apparatus and tunability ofetching rate and?or size through optimization of electrochemi-cal parameters, are valid in the case of solid systems as well. Inour previous reports,9?,10?a pyramidal Nab?Al2O3sinteredpolycrystal was cut, polished, and used as ion conductor witha sharp apex. However, the reproducible fabrication ofb?Al2O3having a sharp apex is difficult because Nab?Al2O3isa hard ceramic material. Thus, the resolution of solid elec-trochemical micromachining was poor?101102mm?. As Nab?Al2O3attains high ion conductivity only at high tempera-ture?873 K?, micromachining had to be performed at thistemperature range.In this study, solid electrochemical micromachining wasperformed using an ion conducting polymer?coated tungstenneedle microelectrode?in place of a Nab?Al2O3pyramid.As is well known, Nafion has high proton conductivity atroom temperature and no anisotropic conduction. Moreover,a variety of metal ions can travel in Nafion in place ofprotons.11?This allows solid electrochemical micromachiningof various metals under mild conditions?room temperature?.Figure 1 shows the schematic systems of solid electrochemicalmicromachining reported in the previous papers7?,8?a?andthe present study?b?. Bard and coworkers7?,8?have reportedselective etching of metal plates?Cu, Ag, Au?coated with apolymer electrolyte film?Fig. 1?a?. However, the etchingsize would depend on the potential distribution generated inthe film. The etching resolution seems lower?102nm?than thepoint contact between tip and polymer electrolyte film?a fewnm2?, and manipulation of the aspect ratio is difficult. Incontrast, the present study employs a tungsten?W?micro-electrode coated with a polymer electrolyte layer, as depictedin Fig. 1?b?. The shape of the apex of an ion conductor can bedirectly transferred to the metal surface because the solidelectrochemical reaction proceeds only at the solidsolidmicrocontact of the polymer and target metal plate. In otherwords, the aspect ratio of the machined surface may be easily673Fig. 1.Schematic system of solid electrochemical micromachiningusing polymer electrolyte proposed by?a?other group7?and?b?thepresent study.Fig. 2.SEM images of W microelectrode before?a?and afterNafion coating?b?.Fig. 3.?a?Polarization curve of?anode?Ag?Nafion?W needle?cathode? ?scan rate: 0.2 V?s?.?b?Typical change of cell voltageduring constant current electrolysis of Ag plate at 1 nA.673Kai KAMADA et al.Journal of the Ceramic Society of Japan115 10 2007designed by the apex configuration of the polymer layer. Inthe present study, the feasibility and current efficiency of solidelectrochemical micromachining of various metals was studiedby using various metals as targets. It has been demonstratedthat many different kinds of metal substrates can be machinedand that submicron resolution can be achieved at room tem-perature.2.Experimental procedureThe experimental model is schematized in Fig. 1?b?. ANafion-coated W?Nafion-W?microelectrode was preparedby electrophoretic deposition of Nafion on the apex of a Wneedle?ca. 1mm in radius of curvature?in 8 mass?sol solu-tion of Nafion, which was prepared by diluting of 20 mass?solution?DuPont DE2020, Total acid capacity: 0.951.03meq?g?with ethanol. A positive bias was applied to the Wneedle because Nafion has a negative surface charge accordingto zeta potential measurements. Figure 2 shows SEM imagesof the W microelectrode before?a?and after?b?Nafion coat-ing. Various metal plates?Ag, Cu, Zn, Mg, Fe, Al, and Ti;thickness: 0.1 mm?were used as target of solid electrochemi-cal micromachining. The Nafion-W microelectrode, whichwas attached to a three-dimensional manipulator, was con-tacted with a horizontally placed metal plate. The typicalmetal?Nafion contact diameter was a fewmm. This valuevaried slightly with the apex configuration of the Nafion layerand contact pressure. Solid electrochemical micromachiningwas performed by applying a constant current or voltage atroom temperature and ambient humidity?297300 K, relativehumidity: 2555?. The slight shift in temperature andhumidity did not affect the experimental results. After micro-machining, the metal surface was observed by SEM, AFM,and laser microscopy, and the elemental distribution in theNafion layer was measured by energy dispersive spectroscopy?EDS?.3.Results and discussion3.1Ion migration mechanism during solid electrochemi-cal micromachiningFigure 1?b?schematized the mechanism of ion migrationobserved during solid electrochemical micromachining using aNafion-W microelectrode. As is well known, Nafion consistsof a hydrophobic fluorocarbon chain matrix and hydrophilicproton conduction channels containing?SO3H groups andH2O molecules. Protons can migrate via the conduction chan-nel by the Grotthuss and?or vehicle mechanism. When a dcelectric field is applied to the cell, the local region of the metalanode at the microcontact is electrochemically oxidized toMn?, which, in turn, is injected into the Nafion via the solidsolid interface. Under a continuous applied electric field, themetal anode is gradually consumed as Mn?. Given the smallcontact size of the metal?Nafion interface?on the order of afewmm?, position-selective dissolution occurs at the micro-contact, and thus solid electrochemical micromachining isaccomplished. At the cathodic interface of Nafion, protons orMn?ions are reduced to H2or M, respectively.3.2Solid electrochemical micromachining of a silverplateSolid electrochemical micromachining of a Ag plate wascarried out under various conditions. Figure 3?a?shows thepolarization curve of Ag anode?Nafion?W needle cathode?0.2 V?s?. The current was extremely small at low voltage and674Fig. 4.SEM images of Ag surface after micromachining at 1 nA for various times. Surface profile along the dashed line estimated by a lasermicroscopy is also shown in?30 min?Fig. 5.?a?SEM image of the Nafion layer after machining at 1 nAfor 30 min.?b?EDS spectra for the points shown in?a?.674Solid Electrochemical Micromachining Using a Tungsten Microelectrode Coated with a Polymer Electrolyteincreased rapidly above ca. 3 V. Application of a constantelectric field of 1 and 3 V for 1 min induced no impressions onthe Ag surface. Given the low overvoltage of tungsten cathodefor H2generation, the actual electric field on the Ag?Nafioninterface may be negligible due to the IR drop at the Nafionlayer.7?In contrast, a depression formed at the microcontactas a result of an anodic electrochemical reaction after applying5 V for 1 min. These results were consistent with the polariza-tion behavior shown in Fig. 3?a?. On the other hand, applica-tion of a large constant current?1mA?caused the Nafionlayer to explode through generation of gaseous H2at thecathodic interface?Nafion?W?. In this case, the current den-sity at the Ag?Nafion interface estimated from circular con-tact?diameter: 5mm?was ca. 5 Acm?2. It was considered thatsuch a high current density may cause the rise in temperatureat the microcontact and the decomposition of electrolyte.Consequently, a maximum of a few tens of nA was suitablefor constant current electrolysis. In following sections, allexperiments were performed under galvanostatic conditions inorder to determine the current efficiency easily.Figure 3?b?shows the time evolution of cell voltage duringAg micromachining under 1 nA. The cell voltage rapidlyincreased to 10 V in the initial stage?1 min?, and thendecreased and remained almost constant at about 4 V after2 min. A similar trend was observed for the Ag?Nab?Al2O3microcontact.10?The initial voltage rise may be due to theinhomogeneous solidsolid contact. Previous papers12?,13?reporting the current-time behavior at the solidsolid interfaceof Ag?Ag?conductors have suggested that the reduction ofthe actual contact area by electrodifussion and productionof atomic scale lattice defects on the Ag surface increasesthe overvoltage under galvanostatic conditions. This effectbecomes much stronger at higher current densities. At longerelectrolysis time?1 min?, the increase in apparent contactarea with time resulting from embedding the Nafion in Ag?i.e., the decrease in current density?would reduce the over-voltage. Figure 4 shows SEM images of Ag surfaces after solidelectrochemical micromachining at 1 nA for various dura-tions. All SEM samples were held at a 40?incline with respectto the perpendicular electron beam axis. The center of themicrographs corresponds to the Ag?Nafion microcontact. Themechanical stress caused by the Nafion-W microelectrodecould be ignored because no change occurred in the absence ofthe electric field. Figure 4 indicates that the Ag plate waslocally etched according to the apex form of the Nafion layer,i.e., a quasi-hemisphere less than 10mm in diameter. The tinyprojections seen on the surface of the depression may be dueto the inhomogeneous distribution of hydrophilic channels inthe hydrophobic matrix. The fact that the sharp edge of thedepressions is clearly visible indicates that the solid electro-chemical reaction occurred only at the Ag?Nafion microcon-tact. Thus, no side etching occurred during micromachining,which is one of the main advantages of the present technique.Naturally, the diameter of the quasi-hemisphere increasedwith electrolysis time.Figure 5?a?shows an SEM image of the Nafion-W micro-electrode after solid electrochemical micromachining?1 nA,30 min?, where the dashed line indicates the position of the Wapex implanted in the Nafion layer. The EDS spectra at pointsa through e in Fig. 5?a?are presented in Fig. 5?b?. Ag wasdetected in the spectra in addition to the S from Nafion. Thisindicates that the electrochemical diffusion of Ag?from the675Fig. 6.?a?Electrolysis time dependence of machining volume andcurrent efficiency of Ag micromachining under a constant appliedcurrent of 1 nA.?b?Change of dominant carrier in the Nafion layer.675Kai KAMADA et al.Journal of the Ceramic Society of Japan115 10 2007Ag plate into the Nafion was induced by the dc bias. Thus, theion migration mechanism proposed above was indeed at playduring electrolysis. The characteristic X-ray intensity of Ag,which is indicative of the Ag concentration, increased withincreasing distance from the microcontact?a?b?c?d?e?.The Ag?that diffused through the Nafion layer was reducedand accumulated at the cathodic Nafion?W interface.14?Ashort circuit between the Ag plate and W needle was construct-ed by Ag deposition inside the Nafion at longer electrolysistimes or using a thinner Nafion layer. In summary, it wasdemonstrated that a Nafion-coated W microelectrode enablessolid electrochemical micromachining under relatively mildconditions?room temperature?and with finer precision?10mm?than is achievable using Nab?Al2O3. In the previousmethod described in Fig. 1?a?, metallic deposits produced atthe polymer?tip cathode interface increased the etchingdimension. In the present study, no expansion of machiningsize was observed using the Nafion-W microelectrode, and theapex configuration of the Nafion layer was directly trans-ferred to the surface of the workpiece. That is, the machiningaccuracy and aspect ratio depended only on the apex dimen-sions of the Nafion layer.3.3Evaluation of current efficiency of Ag micromachiningThe machining size appears to be tunable by adjusting theapplied electricity, which is related to the electrolysis timeunder galvanostatic conditions. The electrolysis time evolutionof the machining size was investigated for a Ag plate at a con-stant current of 1 nA. Figure 6?a?shows the time dependenceof the machining volume estimated on the basis of a surfaceprofile obtained by laser microscopy. The depressions wereassumed to be a part of a sphere, and then their volumes werecalculated from the diameter and depth. The current efficien-cies estimated from the machining volume, applied electricity,and density of silver using Faradays law are also plotted inFig. 6?a?. The depression volume increased continuously astime progressed. Thus, machining size can be easily controlledto within about 100102mm3by varying electrochemical para-meters such as electrolysis time and?or current. The currentefficiencies also increased with electrolysis time, and reached68?at 60 min. The leakage current is expected to be con-sumed by proton conduction in the Nafion layer. As describedin Fig. 6?b?, electrolysis of H2O in air is likely to induce theproduction of H?via the three phase boundary during theinitial stage. At longer electrolysis times, the Nafion layerbecame embedded in the Ag plate, and the Ag?Nafion contactarea increased. Consequently, dissolution of the Ag plate wasfavored over moisture electrolysis, and the current efficiencywas enhanced. The maximum current efficiency in the presentstudy was much higher than that obtained using Nab?Al2O3?about 40?. That is, the Nafion-W microelectrode enabledmuch more efficient solid electrochemical micromachiningand under mild conditions.3.4Solid electrochemical micromachining of Cu, Zn, Mg,and FeNafion is a unique material because numerous types ofmetal ions can be incorporated into the hydrophilic conduc-tion channels instead of protons. That is, a variety of differentkinds of metal substrates can presumably be used as a wor-kpiece. Hence, solid electrochemical micromachining of vari-ous metal plates was attempted. In general, metals can be easi-ly oxidized at high temperature in an oxidizing atmosphere,whereby a thick oxide film is formed on surface. In the case ofmicromachining using Nab?Al2O3at high temperature, thepresence of the oxide film suppresses the anodic dissolution ofmetal, and an inert atmosphere is required to prevent surfaceoxidation. Also, metals having a low melting temperaturecould not be employed as a target of micromachining. Owingto the high ion conductivity of Nafion even at room tempera-ture, various kinds of metals can be used as a target withoutthe restrictions mentioned above. Figure 7 shows SEM imagesof the surface of Cu, Zn, and Mg plates after solid electro-chemical micromachining. The images suggest that the depres-sions were produced during electrolysis in similar manner tothe Ag plate. EDS analysis revealed the presence of eachmetallic element in the Nafion layer after electrolysis. Hence,solid electrochemical micromachining of these metals mayalso be possible. As shown in Fig. 7, the surfaces of thedepressions were rougher than those in the case of Ag. It hasbeen reported that the exchange current between the Cu2?dis-solving in Nafion and the Cu plate coarsened the surface.7?The variations in cell voltage observed in the case of Cu, Zn,Mg, and Fe were quite different from that in the case of Ag,and tended to increase with time. According to the EDSspectra, a small amount of oxygen was detected in the metalsurfaces. The oxide?hydroxide, hydrated oxide?formed onthe surface anodically, accompanied by the anodic dissolu-tion. Table 1 summarizes the results of solid electrochemicalmicromachining for given constant current values. Cu andFe were presumed to be dissolved as Cu2?and Fe3?, respec-tively.15?The current efficiencies of Cu, Zn, Mg, and Fe wereone?two orders magnitude lower than that of Ag. It wasreported that the substitution of small amount of metal ions?30?for protons does not interrupt the ion conduction inNafion.11?Therefore, the surface oxide would act as a barrierto anodic dissolution. This is thought to be the main reasonfor the low efficiencies. Table 1 also indicates that applyinga larger constant current reduces the efficiency, and thus,a smaller current is more appropriate for effective micro-676Fig. 7.SEM images of etched metal surfaces under various condi-tions for 60 min.Table 1.Machining Volumes and Current Efficiencies of SolidElectrochemical Micromachining?60 min?Fig. 8.AFM image of Al plate after applying 20 nA for 60 min.676Solid Electrochemical Micromachining Using a Tungsten Microelectrode Coated with a Polymer Electrolytemachining.3.5Anodic electrolysis of Al and Ti using the Nafion-WmicroelectrodeIn the case of the Al and Ti workpieces, no local anodic dis-solution was detected; a passive oxide layer formed on theirsurface. Figure 8 is an AFM image taken near the microcon-tact of the Al surface after electrolysis at 20 nA for 60 min.Clearly, the metal surface around the microcontact has liftedoff. SEM observation and EDS analysis of the cross-section ofAl and Ti plates revealed that the surface layer consists of adense oxide film. As shown in Fig. 8, the thicker oxide layerformed along the circumference of the microcontact betweenNafion and Al. Thus, oxide growth was promoted at the threephase boundary. It was confirmed that Al3?or TiO2?can beexchanged in the Nafion membrane by immersion in an aque-ous AlCl3or TiOCl2solution. However, no evidence of anodicdissolution of Al or Ti was found in the present study. In thecase of Al and Ti, the metal ions migrating through the oxidefilm reacted readily with H2O and induced the growth of athick passive layer. Although Mg also produces an anodicoxide film in aqueous solution, similarly to Al and Ti, solidelectrochemical micromachining was successful, as shown inFig. 7. It is well known that Mg is not coated with a barrier?dense?oxide film by anodic treatment because the volumeratio of oxide?metal is smaller than unity. The local dissolu-tion of Mg2?may proceed via the defects in the passiveoxide layer. The high solubility of Mg2?in neutral to acidicsolutions16?may also be one of the reasons for the local disso-lution of Mg observed when using the Nafion-W micro-electrode. Thus, metals that form a dense and chemicallystable surface oxide are difficult to micromachine by thepresent technique. Nevertheless, it may be possible to patternthe oxide layer using the Nafion-W microelectrode.3.6Fabrication of etching pattern by scanning Nafion-WmicroelectrodeSolid electrochemical micromachining occurs only at thesolidsolid interface between Nafion and the metal substrate.Thus, micromachining could conceivably enable the fabrica-tion of patterned metal substrates if the Nafion-W micro-electrode were to be moved along the metal surface duringelectrolysis. To groove the Ag plate on a submicron scale, aNafion-W microelectrode equipped with a three-dimensionalmanipulator was scanned along the Ag surface under anapplied electric field; a W microelectrode coated with a thinNafion layer?1mm?was used to attain fine resolution.Figure 9 is an AFM image of an Ag surface obtained by scan-ning the Nafion-W microelectrode?50 nm?s?at 1 nA. Asexpected, a single track was produced along the pathway ofthe microelectrode. Thus, scanning of the Nafion-W micro-electrode yielded a micropattern of tracks on a submicronscale?width: 0.4mm, depth: 0.1mm?. Furthermore, it was677Fig. 9.AFM image of Ag surface?1 nA?after scanning with aNafion-W microelectrode?10mm?s?.677Kai KAMADA et al.Journal of the Ceramic Society of Japan115 10 2007confirmed that increasing the constant current broadened theline and that the width at any given current was inverselyproportional to the scan rate. That is, the track size dependedon the current applied per unit area per unit time. As thefundamental micromachining mechanism is the same as in thecase of the fixed microelectrode, a variety of metal substratescan be patterned by manipulating the ion conductor. Since theNafion-W microelectrode is attached to the manipulator, avariety of patterns, including not only simple patterns?line ordot?, but also more complex structures, can be fabricated tomeet specific design criteria.4.ConclusionsThe present study demonstrated that the use of a Nafion-coated tungsten microelectrode enables solid electrochemicalmicromachining of metal substrates with high resolution atambient condition. The metal substrates were dissolved locallyand anodically at the microcontact with the ion-conductingNafion. The accuracy of micromachining was improved ascompared with our previous reports using Nab?Al2O3, androom-temperature operation was achieved. The present tech-nique was applied to various metal substrates?Ag, Cu, Zn,etc.?. By coating a W microelectrode with Nafion, the apexshape of a Nafion layer could be transferred directly to themetal surface without any detectable side etching or expansionof machining dimensions. The formation of a surface oxidecaused a cu

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