微细阵列方形轴孔的电火花和电化学组合加工工艺研究

对微细阵列轴孔的电火花、电化学组合加工工艺进行了分析和研究.用微细电火花线切割机加工出3×3至10×10系列方形阵列电极,宽度在25～90 μm, 加工中采用降低加工电压、加工电流、进给速度和减小工作液冲击等方法,获得了质量较好的阵列电极,并分别利用微细电化学加工和微细电火花加工两种工艺方法进行阵列孔加工.在加工过程中通过适度间歇抬刀、超声振动、循环流动工作液等方法,较好地解决了微弧放电、排屑、加工区温度过高等加工难题,获得了质量较好的大小在30～100 μm相应的阵列孔,从而实现了微细阵列轴孔的电火花、电化学组合加工,为大规模微细阵列轴孔的加工开辟了高效、可行的新工艺方法.     

微细电化学加工的自适应进给控制系统

为实现微细电化学加工间隙的精确控制，达到稳定间隙乃至恒间隙加工，对加工间隙进行建模，提出并实现一种微细电化学加工进给自适应控制系统。采用嵌入式控制器结合专用集成电路的控制结构，设计软硬件实现间隙控制系统与加工实验装置，分别利用酸、碱电解液进行加工实验，实现了400、600 μm的微小孔。实验结果表明：设计的微细加工自适应控制系统与实验装置能够保证稳定加工间隙，满足微细加工工艺要求。     

微细电加工应用技术研究

微细电加工要达到工业应用的目的,需兼顾加工效率和加工精度两方面的要求.以微细孔、微细三维结构的加工为目标,进行了微细孔电火花加工、三维微细结构电火花伺服扫描加工及微细电化学加工技术的研究开发.设计出微细电极的损耗补偿进给和导向机构,开发出三维微细结构的电火花伺服扫描加工工艺,研究了采用阵列微细电极的微细电化学加工方法.微细孔电火花加工可连续加工直径小至100 μm的孔.伺服扫描电火花加工可便捷地在小于1 mm2区域内加工出三维微细结构.提出的微细电化学加工技术路线拟将微细电解加工应用于阵列微细孔和三维微细结构的加工.     

微细电化学加工电源的设计与研究

加工电源的频率、波形等输出特性在很大程度上影响微细电化学加工的效果。本文提出的微细电化学加工电源系统包括硬件和软件两个模块，其中硬件模块包括计算机、接口电路、功率放大电路和信号检测电路；软件模模包括驱动程序和控制程序。该电源系统可产生多种波形，且能实现对加工过程的自适应控制，从而满足微细电化学加工工艺研究的需求。     

微细轴的电加工技术

针对微细轴的加工问题，分析了当前普遍使用的特种加工方法。分别对线电极磨削、块电极反拷、单脉冲放电、电火花沉积、电解加工和电化学沉积等加工方法在微细轴加工方面的特点进行了归纳，并给出了具有代表性的加工实例。     

电化学腐蚀法制备倒锥状微细电极的试验研究

以电化学腐蚀加工法为基础,提出了一种加工复杂形状微细电极的工艺方法.利用端面绝缘的方法改变阳极的局部导电性,使阳极和阴极之间的电场分布发生变化,从而得到倒锥状微细电极.通过试验成功地制备出倒锥状微细电极,并结合对比圆柱状电极进行了微孔电解加工试验,结果证明倒锥状电极在微孔电解加工中能获得更好的加工定域性.     

基于CPLD的纳秒级微细电化学加工脉冲电源的研究

为了提高微细电化学加工的加工精度和表面质量,从加工模型入手,探讨了高频脉冲电源对微细加工的影响,并基于CPLD研制了超短脉冲电源,输出脉冲宽度为20 ns以下,脉冲调节范围较大.使用该电源进行相应的工艺试验,取得了较好的效果.     

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。     

基于CPLD的多功能微细电加工电源的研制

为了解决微能脉冲电源发展中遇到的功能单一、集成度不高等问题,设计了多功能微细电加工脉冲电源.以单片机和CPLD作为微控制器,利用模块化的方法对关键模块进行设计,并运用Quartus软件对高频脉冲发生单元进行仿真,得到微细电火花和微细电化学的脉冲波形,通过对脉冲的切换实现了微细电火花和微细电化学的加工.     

基于特种加工的微细制造技术

通过例证概括介绍了特种加工方法在微细加工方面所取得的成就，这些加工技术包括：电火花加工、电化学加工、超声加工、激光加工、精密电铸等。阐述了特种加工技术在微细制造方面的特点：擅长加工复杂的三维微机械结构，且投资小，适于中小批量生产。     

Experimental investigation into electrochemical micromachining (EMM) process

Due to several advantages and wider range of applications, electrochemical micromachining (EMM) is considered to be one of the most effective advanced future micromachining techniques. A suitable EMM setup mainly consists of various components and sub-systems, e.g. mechanical machining unit, micro-tooling system, electrical power and controlling system and controlled electrolyte flow system etc. have been developed successfully to control electrochemical machining (ECM) parameters to meet the micromachining requirements. Investigation indicates most effective zone of predominant process parameters such as machining voltage and electrolyte concentration, which give the appreciable amount of material removal rate (MRR) with less overcut. The experimental results and analysis on EMM will open up more application possibilities for EMM.     

Experimental investigation on the influence of electrochemical machining parameters on machining rate and accuracy in micromachining domain

Non-conventional machining is increasing in importance due to some of the specific advantages which can be exploited during micromachining operation. Electrochemical micromachining (EMM) appears to be a promising technique, since in many areas of application, it offers several special advantages that include higher machining rate, better precision and control, and a wider range of materials that can be machined. A better understanding of high rate anodic dissolution is urgently required for EMM to become a widely employed manufacturing process in the micro-manufacturing domain. An attempt has been made to develop an EMM experimental set-up for carrying out in depth research for achieving a satisfactory control of the EMM process parameters to meet the micromachining requirements. Keeping in view these requirements, sets of experiments have been carried out to investigate the influence of some of the predominant electrochemical process parameters such as machining voltage, electrolyte concentration, pulse on time and frequency of pulsed power supply on the material removal rate (MRR) and accuracy to fulfil the effective utilization of electrochemical machining system for micromachining. A machining voltage range of 6 to 10 V gives an appreciable amount of MRR at moderate accuracy. According to the present investigation, the most effective zone of pulse on time and electrolyte concentration can be considered as 10–15 ms and 15–20 g/l, respectively, which gives an appreciable amount of MRR as well as lesser overcut. From the SEM micrographs of the machined jobs, it may be observed that a lower value of electrolyte concentration with higher machining voltage and moderate value of pulse on time will produce a more accurate shape with less overcut at moderate MRR. Micro-sparks occurring during micromachining operation causes uncontrolled material removal which results in improper shape and low accuracy. The present experimental investigation and analysis fulfils various requirements of micromachining and the effective utilization of ECM in the micromachining domain will be further strengthened.     

微细阵列孔的电解加工精度研究

从电解加工的特点出发,对影响微细阵列孔加工精度的因素进行了分析.电解加工过程中,工具阴极和工件阳极之间存在加工间隙是导致误差的根源.微细阵列孔的电解加工误差可分为复制误差和重复误差,电场强度的分布状态和杂散腐蚀是造成复制误差的最重要因素,而气泡在加工区域的堆积导致了重复误差的产生.通过理论和实验分析,为实验加工提供了提高加工精度的措施和办法.     

Impact of the shape of electrode-tool on radical overcut of micro-hole in electrochemical micromachining

To make use of the full capability of electrochemical micro-machining (EMM), a meticulous research is needed to improve the material removal, surface quality and accuracy by optimizing various EMM process parameters. Keeping this in view, an indigenous development of an EMM machine set-up has been considered to carry out a systematic research for achieving a satisfactory control on the EMM process parameters to meet the micromachining requirements. In this study an EMM machine has been developed and experiments were conducted to study the influence of some of the major process parameters such as the machining voltage, electrolyte concentrations, the pulse-on-time and the machining current on the machining rate and accuracy. The effect of the shape of the tool electrode tips on EMM has been investigated experimentally with 304 stainless steel sheets. The machining rate and the overcut are significantly influenced by the shape of the tool electrode tip.     

微细组合电加工样机研制及实验研究

基于新研发的一套微细组合电加工样机μEM-200CDS2,介绍了研发过程中探索出的最小脉宽可以达纳秒级的双功能微能脉冲电源以及样机中的若干关键技术,包括放电状态的双参数检测技术、工具电极在位多功能磨削技术、工作液稳定供给控制技术等。其中,双功能微能脉冲电源具备主动消电离环节,可以减少脉间的残余电荷放电,有利于提高加工表面质量;组合电加工样机床身设计有利于提高系统的加工精度和效率。最后,结合小孔的加工试验研究了典型的组合电加工工艺过程,结果表明:该过程中,可以并行完成工具电极在位修整与零件加工,有利于提高微小特征的加工效率。     

Influence of vibration on micro-tool fabrication by electrochemical machining

Recent trend in societies is to have micro products in limited space. Efficient micromachining technologies are essential to fabricate micro products which in turn will be helpful in saving material, energy and enhancing functionality. For micromachining, micro tool is very much essential. This paper is aimed at finding the most suitable and quickest method of micro tool fabrication by electrochemical machining. Tungsten micro tools were fabricated at different machining conditions to know the influences of voltage, frequency of tool vibration, amplitude of vibration of tungsten tool, concentrations of electrolyte and dipping length of tool inside the electrolyte. Fabrication of uniform diameter of micro tool is possible at each applied voltage starting at 2 V to higher volt utilizing vibration with appropriate amplitude. Good quality micro tools with different shapes can be fabricated by controlling a proper diffusion layer thickness within a very short time introducing the vibrations of micro tool. Finally, the fabricated micro tools were applied for machining precise micro holes and micro channel using electrochemical micromachining (EMM).     

光刻胶掩膜微细电化学加工参数的试验研究

对光刻胶掩膜微细电化学加工参数进行了试验分析研究，发现光刻胶厚度、开口角度、咏冲电源频率、脉宽及电解液配方对加工质量都有影响，在此基础上提出改善加工质量的可行性方案。     

某型航空发动机燃油喷嘴旋流室的微细电解加工研究

针对某型航空发动机燃油喷嘴结构尺寸微小、材料硬度较高、切削加工困难等问题,介绍了微细电解加工的原理和实验装置,制备了微细棒状工具电极和三角形钩状成形电极,利用分层电解铣削进行粗加工快速去除工件多余材料,再利用环形扫描电解铣削进行旋流室全锥面的精加工,实现了发动机喷嘴微小尺寸旋流室的微细电解加工成形,达到加工精度和表面质量要求。研究表明,微细电解铣削加工是加工金属材料微小结构的有效可行的方法。     

Influence of tool vibration on machining performance in electrochemical micro-machining of copper

Electrochemical micro-machining (EMM) appears to be promising as a future micro-machining technique since in many areas of applications, it offers several advantages, including biomedical and MEMS applications. A suitable micro-tool vibration system has been developed, which consists of tool-holding unit, micro-tool vibrating unit, etc. The developed system was used successfully to control material removal rate (MRR) and machining accuracy to meet the micro-machining requirements. Micro-holes have been produced on thin copper workpiece by EMM with stainless-steel micro-tool. Experiments have been carried out to investigate the most effective values of process parameters such as micro-tool vibration frequency, amplitude and electrolyte concentration for producing micro-hole with high accuracy and appreciable amount of MRR. From the experimental results and SEM micrographs, it is evident that the introduction of micro-tool vibration improves EMM performance characteristics. Lower electrolyte concentration in the range of 15–20 g/l reduces stray current effects. Hertz (Hz) range of tool vibration frequency improves the removal of sludge and precipitates from very small interelectrode gap. The 150–200 Hz range of tool vibration frequency can be recommended for EMM, which provides a better electrochemical machining in the narrow end gap. Compared to kHz range, Hz range micro-tool's vibration improves the MRR and accuracy in EMM.     

Electrochemical micromachining of microstructures of micro hole and dimple array

This paper proposes a method of electrochemical micromachining of micro hole or dimple array, in which a patterned insulation plate coated with metal film as cathode is closely attached to workpiece plate. When voltage is applied across the workpiece and cathode film over which the electrolyte flows at high speed, hole or dimple array will be produced. The proposed technology offers unique advantages such as short lead time and low cost. The effect of process parameters on the microstructure shape was demonstrated numerically and experimentally. Arrays of holes or dimples of several hundred micrometers diameter have been produced.