金属微孔网板微细电解加工技术研究

提出了采用微细圆柱群电极电解加工金属网板微孔的工艺方法.以电化学腐蚀法制备了直径(72 μm)一致的单排微细圆柱群电极,并用此群电极为工具阴极,进行了网板微孔的电解加工工艺试验,实现了金属微孔网板的稳定电解加工.     

微细电解加工用电极的侧壁绝缘及应用实验

介绍了一种微细电解加工用电极的侧壁绝缘方法及其应用实验.采用旋涂法在电极表面涂敷液态环氧树脂并固化处理,重复该过程形成多层绝缘薄膜,用机械磨削法去除电极端部的绝缘膜,使电极端面导电.通过基础工艺实验优化了旋涂法工艺参数,通过对比实验验证了侧壁绝缘电极的微孔加工效果.旋涂法可制得膜厚为5～10 μm的侧壁绝缘电极,采用该电极加工可显著减小微孔直径及锥度,提高微细电解加工尺寸精度.     

综合改善微细电解加工精度的工艺研究

电解加工的阳极电化学溶解原理使其在微细加工领域具有巨大的发展潜力,但杂散腐蚀和流场条件恶劣制约加工精度的提高.分析了影响微细电解加工的主要因素,提出综合改善微细电解加工精度的工艺途径.理论分析和实验研究均表明:将LIGA工艺制备高质量微细阵列电极、电极侧壁绝缘、高频脉冲电流及非线性电解液加工、电极间歇回退伺服控制等方法有机结合,能有效约束电场、改善流场,提高微细电解加工的精度.     

基于可重构方法设计的多功能微细电加工系统

简要介绍了可重构制造系统的概念和可重构机床的特点。基于可重构机床模块化的设计方法,设计了一套可进行微细电火花加工和微细电解加工的多功能微细电加工系统。在多功能系统中利用在线电解的方法制备微细钨电极,并用此电极进行电火花微细孔加工试验。     

微细孔电火花加工设备及其加工实验研究

开发了一种电极丝辅助激振微细孔电火花加工设备,主要由微细电极丝伺服进给与导向模块、加工状态监测与控制模块、高频脉冲电源、微细电极丝辅助激振模块以及工作液循环系统等组成.采用拉拔微细钨丝作为工具电极,可加工直径100～300 μm的微孔及阵列微细孔.实验结果表明,使用直径0.07 mm的电极丝可连续稳定地进行阵列微孔的加工(孔径为100 μm,16×16阵列).加工使用的微细电极丝最小直径为50 μm.     

应用线电极磨削法的电火花微孔加工

在微细电火花微孔加工中,微细工具电极的制作精度是决定微孔加工质量的关键。本文介绍了作者研制的微细电火花加工样机。该机床应用了线电极电火花磨削法制作微细轴,并在同一台机床上用制作的微细轴作为工具电极加工微孔;同时为提高微孔的加工质量,采用了主轴横轴布局结构。该机床还采用了微能放电电源、去离子水工作液等加工工艺。经过实验加工,获得了高质量的微细轴以及微孔。     

应用线电极磨削法的电火花微孔加工

在微细电火花微孔加工中，微细工具电极的制作精度是决定微孔加工质量的关键。本文介绍了作者研制的微细电火花加工样机。该机床应用了线电极电火花磨削法制作微细轴，并在同一台机床上用制作的微细轴作为工具电极加工微孔；同时为提高微孔的加工质量，采用了主轴横轴布局结构。该机床还采用了微能放电电源、去离子水工作液等加工工艺。经过实验加工，获得了高质量的微细轴以及微孔。     

微结构超声复合加工机理分析与试验

提出制作微结构的超声复合电加工方法.分析微细超声、超声复合电火花、超声复合电解微细加工过程机理.用微细放电组合技术制作多种截面形状微细工具电极;完善超声复合电加工试验系统,进行了多种材料、形状的微结构超声复合加工试验.结果表明:用超声加工是制作硬脆材料微结构的有效方法,用超声复合电火花制作的金属材料微结构有好的精度及稳定性;超声复合电解加工兼有效率高、精度好的技术优势.     

微细盘状电极制备及其微细电解加工研究

基于电化学腐蚀加工方法,提出了一种微细盘状电极的制备方法。先采用平板阴极电化学腐蚀法,将毛坯加工成圆柱状微细电极,再对圆柱电极端部进行绝缘保护,进一步腐蚀制备得到微细盘状电极。利用微细圆柱电极、盘状电极和盘状群电极,在厚1 mm的304不锈钢片上进行电解加工对比实验,结果证明采用微细盘状电极电解加工微小孔,其加工定域性有明显改善,侧壁间隙减小,且降低了孔锥度。     

微流控芯片注塑模具的微细电解加工

基于电解加工电极不损耗的优势,研究了一种微细电解加工微流控芯片注塑模具微结构的工艺,针对微小V型槽和微孔,解决微细电极在线制备和测量、微结构成形精度、群微结构加工等关键问题。加工实验结果表明:该工艺可实现曲线V型槽和群微结构加工,通过微细电解加工的模具具有较高的形状精度和表面质量。     

自成形微细电极制备技术研究

以目前微细电火花加工中微细电极常用的制备技术为基础,提出了自成形微细电极制备技术。通过研究,掌握了自成形微细电极制备技术工艺关键,并与传统制备方法的反拷块法进行了实验对比,获得了较为理想外形尺寸精度、长径比的电极。     

The analysis and investigation on the microelectrode fabrication by electrochemical machining

Electrochemical machining (ECM), also called the electrolysis machining, has become more and more important in micro-machining in recent years. In this paper, a 510 μm tungsten rod was used as the anode, and nickel plates were used as the cathode to fabricate the micro-pin used in scanning tunneling microscope (STM) by electrochemical polishing. Different from the needle shape in STM, a cylindrical shape of microelectrode is desired for the application in electrochemical drilling. The influence of working parameters on the electrode shape is investigated.Experimental results show that low applied voltage, high concentration electrolyte and an appropriate rotation of electrode are preferred to fabricate microelectrodes with diameter less than 100 μm. A higher rotational speed may result in an electrode of conical shape.     

电铸复杂回转零件时新型象形阳极的应用

通过对电铸时沉积金属的分布进行理论分析，提出采用象形阳极改善复杂形状零件电铸时沉积分布的不均匀性。在合金电铸复杂回转零件时设计了一种新型的象形阳极结构．由此试验得到了较好的电铸层厚度及合金成分的均匀分布。     

Effects of precipitates on the electrochemical performance of Al sacrificial anode

The influence of precipitates on the electrochemical performance of Al–Zn–In–Mg–Ti–Si sacrificial anode was investigated by the TEM observation and electrochemical measurements. The results indicate that the shape and size of precipitates in the alloys has great impact on the electrochemical performance. The anodes with rod-like precipitates are easily corroded along grain boundaries, resulting in the low current efficiency caused by serious grain loss. In comparison, the anodes with spherical or discal precipitates have high current efficiency and even corrosion morphology. The precipitates with a size of about 400 nm are conducive to improve the electrochemical performance of anodes.     

Prediction of anode profile in ECBD and ECDoperations

During electrochemical drilling, use of bit type of tools produce more accurate holes as compared to bare type of tools. But, no model is available to predict anode profiles obtained during electrochemical bit drilling (ECBD). In this paper, models SBFET-11 (one dimensional analysis) and SBFET-22 (two dimensional analysis), based on finite element technique, have been proposed. The models are capable to predict the workpiece shape and size obtained either by bit type of tool or bare type of tool. The models can analyse both types of workpieces, i.e. the workpiece having a predrilled hole and the workpiece without a predrilled hole. Some assumptions made in earlier models regarding zero void fraction, constant electrolyte flow velocity, zero feed rate in transition and side zones etc., have been relaxed. Special attention has been paid on the analysis of anode profile in the transition zone and its effects on the accuracy of the computed anode profile in side zone. Comparison of analytical and experimental anode profiles has revealed a good agreement between the two.     

Fabrication of complex shape electrodes by localized electrochemical deposition

Localized electrochemical deposition (LECD) is a promising technology for fabrication of high-aspect ratio electrode of various materials. This technology is found to be one of the simple and inexpensive ways to fabricate electrodes for micro-EDM. This study presents a novel method to manufacture electrodes with complex cross-section using mask of non-conductive material. In this study, the mask is placed between the anode and cathode, which is immersed in mixed electrolyte of copper sulfate, 1.0 M sulfuric acid and as an additive agent 0.04 g/l of thiourea. The deposition of copper is localized on the cathode surface using a mask and applying ultra short voltage pulses between the anode and cathode. In this setup the cathode is placed above the anode and mask, so that the deposited electrode can be used directly for EDM or any application without changing tool orientation. The deposition characteristics such as size, shape, surface, and structural density according to gap between the anode and mask, applied voltage, pulse frequency and duty ratio have been investigated in this study. Finally, appropriate conditions have been found out for effective fabrication of smooth and fine-grained deposited electrodes based on the findings of the various experiments.     

Effect of Different Shapes of the Titanium Based IrO2-Ta2O5 Coatings Anode on Electrochemical Properties

钛基IrO2-Ta2O5涂层阳极的形状分别是板状和扩张网。采用涂覆了H2IrCl6.H2O的盐酸溶液和TaCl5乙醇溶液的混合溶液再进行热分解制备得到IrO2-Ta2O5涂层。分别采用SEM,EDX,CV和加速寿命测试对电极的微观结构和电化学性能进行分析。相对板状电极而言,由于较少的活性物质IrO2在电极表面结晶析出,扩张网状电极具有更低的电化学催化活性。但是由于表面的裂纹较为细密、表面活性元素分布也较为均匀,并且其纵截面的形状更有利于电解析出的气泡排出,扩张网状电极具有更长的加速寿命。     

冰晶石熔盐中阳极效应时石墨阳极的电化学行为(英文)

在1000℃下采用循环伏安法研究石墨阳极在冰晶石氧化铝熔盐中的阳极电化学行为。讨论了循环伏安曲线中较高的电流峰。结果表明,在高电位条件下,一种含氧氟络合阴离子中的氟与碳阳极反应,且在阳极表面生成一层高电阻的CF膜。在含0.5%氧化铝的电解质中,石墨电极钝化电位为3.28V,并随着氧化铝含量的增加而增大。这一现象表明,在冰晶石-氧化铝熔盐体系中氧化铝含量对阳极过程起着主导作用。     

土壤介质中阴极保护用混合金属氧化物涂层钛阳极的研究

采用热分解方法制备了混合金属氧化物(MMO)涂层钛阳极。研究了钛阳极在土壤介质中的电化学行为,用SEM观察了涂层形貌,并研究了阳极寿命与涂层厚度和电流密度之间的关系。结果表明,所研制的涂层钛阳极具有良好的电化学性能和较长的使用寿命,是土壤介质外加电流阴极保护中比较理想的辅助阳极。     

钢筋混凝土结构中阴极保护用MMO涂层钛阳极的研究

采用热分解法制备了IrTa-X混合金属氧化物（MMO）涂层钛阳极。通过极化曲线研究了钛阳极的电化学性能，用SEM观察了涂层形貌，研究了阳极寿命与涂层厚度和电流密度之间的关系，并与国外阳极试样的寿命做了一对比。结果表明，所研制的涂层钛阳极具有良好的电化学性能和较长的使用寿命，是钢筋混凝土结构外加电流阴极保护中比较理想的辅助阳极。