微细群电极的加工及其封装技术

介绍了微细群电极的应用情况,分别给出了LIGA方法、电火花超声复合反拷加工法和电火花线切割加工法制作群电极的工作原理,并对这些工艺的特点进行了归纳,给出了具有代表性的加工实例,最后介绍了微细群电极的封装技术.     

电火花加工工具电极制备技术研究进展

工具电极是电火花加工中非常重要的一项因素,电极的制备是实现电火花加工的关键.本文介绍了电火花加工工具电极制备技术最新的研究进展,包括石墨电极、聚合物复合材料电极、电火花表面改性电极、电火花磨削用电极和微细电极的制备方法,以及电铸法和基于快速成形技术的电极制备方法等.     

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.     

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。     

微细电火花加工实现条件的研究

介绍了微细电火花加工的原理和特点,从加工表面质量、脉冲电源、微细工具电极的制造和安装、放电面积效应的影响、伺服控制系统等方面对微细电火花加工的实现条件进行了研究,并给出了微细轴的电火花加工等具体加工实例.研究结果对微细电火花加工技术的具体应用具有重要的参考价值和指导意义.     

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。     

电火花摇动加工微细阵列轴和孔的试验研究

针对微细阵列轴和孔的电火花加工,提出了利用数控电火花加工机床摇动功能的摇动加工微细阵列轴和孔的方法.此法是基于电火花反拷贝加工的原理,先用丝电极在薄平板(中间电极)上按要加工的阵列轴和孔间距或数倍间距加工阵列小孔(直径0.1 mm以上),然后用加工的薄平板(中间电极)作电极,电火花摇动加工微细阵列轴(电极),最后用此微细阵列电极加工阵列孔.进行了电火花摇动加工微细阵列电极试验,得到了单电极直径为50 μm、长径比为16的3×3阵列电极,并用此电极在70 μm厚的不锈钢板上加工出单孔直径为70 μm的3×3微细阵列孔.试验结果表明,电火花摇动加工方法可实现微细阵列轴和孔的加工.     

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.     

群孔的微细电火花加工技术研究

对微细电火花群孔加工工艺进行了分析和研究。用微细电火花加工机床加工出单电极,并用该电极加工出2×2直径约100μm的阵列孔,在此过程中采用加大加工长度和适度欠补偿的方法,获得了质量较好的阵列孔。用此阵列孔作为工具加工出了2×2直径约100μm的群电极,然后用此群电极一次加工出2×2直径约100μm的群孔,从而实现了微细电火花阵列孔的加工。     

基于高速铣削的微细电极加工方法

微模具型腔的高效、高精密加工,一直是制约微模具制造技术发展的瓶颈问题.以微细 电火花加工用的圆柱阵列结构微细电极为对象,研究了应用高速铣削加工技术,实现微细电极的高效、高精密加工方法.通过优化分析微细电极结构和高速铣削加工参数及刀具路径,获得了尺寸和形状精度及表面质量均满足要求的阵列结构微细电极,并以制得的微细电极进行...     

利用LIGA技术研制微细电火花异形和阵列结构电极

利用LIGA技术的优势,针对电火花电板结构特点开发出相应的加工工艺,完成电火花复杂结构电极的制造.电火花电极的特点是大高宽比的金属柱状结构,这对于LIGA技术工艺具有特殊的难度,需要突破深孔显影和电铸工艺难题.通过大量的工艺试验,优化出电火花电极阵列结构的工艺路线,圆满完成阵列结构和异形复杂结构的电极制造,为电火花技术...     

MEMS的微细加工技术

介绍了目前比较前沿的几种微型腔的机械加工方法：光刻掩模、高能束刻蚀（激光刻蚀）和LIGA技术等加工方法。对这些技术的发展趋势进行了展望。指出微器件的推广和应用，是和微器件的加工方法密不可分的，特别是随着激光加工技术在微机械加工领域的推广和应用．微器件的加工工艺水平和加工质量会有更大的提高。     

纳米技术与特种加工

对纳米技术与特种加工进行了简要的分析和讨论，内容包括：微细刻蚀、LIGA、微细特种加工、纳米切削、基于扫描探针技术的纳米加工等。     

A simple approach for robust design of high-speed electrical-discharge machining technology

The paper presents a simple approach for optimizing high-speed electrical-discharge machining (EDM). The approach begins with designing the ideal function of an EDM system coupled with Taguchi methods for process optimization. It has been proposed that the ideal function has a linear relationship between the input signal (intended dimension) and the output response (product dimension). This model seeks to develop a robust machining process enabling high precision and accuracy of machining a product.In this study, a two-step optimization strategy has been applied. The first step is to reduce the functional variability of the EDM system to enhance process robustness. The second step is to increase the machining accuracy by adjusting the slope of the best-fit line between the input signals and the output responses. Experimental results have shown that the use of the proposed model is simple, effective, and efficient in the development of robust and high-quality EDM machining processes.     

State of the art electrical discharge machining (EDM)

Electrical discharge machining (EDM) is a well-established machining option for manufacturing geometrically complex or hard material parts that are extremely difficult-to-machine by conventional machining processes. The non-contact machining technique has been continuously evolving from a mere tool and die making process to a micro-scale application machining alternative attracting a significant amount of research interests.In recent years, EDM researchers have explored a number of ways to improve the sparking efficiency including some unique experimental concepts that depart from the EDM traditional sparking phenomenon. Despite a range of different approaches, this new research shares the same objectives of achieving more efficient metal removal coupled with a reduction in tool wear and improved surface quality.This paper reviews the research work carried out from the inception to the development of die-sinking EDM within the past decade. It reports on the EDM research relating to improving performance measures, optimising the process variables, monitoring and control the sparking process, simplifying the electrode design and manufacture. A range of EDM applications are highlighted together with the development of hybrid machining processes. The final part of the paper discusses these developments and outlines the trends for future EDM research.     

Experimental characterization of material removal in dry electrical discharge drilling

Dry electrical discharge machining is one of the novel EDM variants, which uses gas as dielectric fluid. Experimental characterization of material removal in dry electrical discharge drilling technique is presented in this paper. It is based on six-factor, three-level experiment using L₂₇ orthogonal array. All the experiments were performed in a ‘quasi-explosion’ mode by controlling pulse ‘off-time’ so as to maximize the material removal rate (MRR). Furthermore, an enclosure was provided around the electrodes with the aim to create a back pressure thereby restricting expansion of the plasma in the dry EDM process. The main response variables analyzed in this work were MRR, tool wear rate (TWR), oversize and compositional variation across the machined cross-sections. Statistical analysis of the results show that discharge current (I), gap voltage (V) and rotational speed (N) significantly influence MRR. TWR was found close to zero in most of the experiments. A predominant deposition of melted and eroded work material on the electrode surface instead of tool wear was evident. Compositional variation in the machined surface has been analyzed using EDAX; it showed migration of tool and shielding material into the work material. The study also analyzed erosion characteristics of a single-discharge in the dry EDM process vis-á-vis the conventional liquid dielectric EDM. It was observed that at low discharge energies, single-discharge in dry EDM could give larger MRR and crater radius as compared to that of the conventional liquid dielectric EDM.     

Development of peeling tool for micro-EDM

We propose a simple and fast fabricating method of tool electrode for micro-EDM. A ‘peeling tool’, a wire coated with a different material, has been developed as an interim product for a microelectrode. A zinc layer was coated by electroplating on a tungsten electrode of 100 μm diameter. The zinc layer makes both handling and chucking of the electrode easy. Part of the zinc layer is instantly ‘peeled’ by a single discharge, exposing tungsten electrode under the zinc layer undamaged and the exposed electrode can be used in microhole drilling by EDM. Time-resolved imaging revealed the peeling process dynamically.     

Sequential Laser and EDM Micro-drilling for Next Generation Fuel Injection Nozzle Manufacture

High quality holes of diameters less than 145 μm are required for the manufacture of next generation diesel fuel injection nozzles for improved combustion efficiency and reduction of emission to the environment. The current practice of using electro-discharge machining (EDM) drilling of fuel injection nozzles is limited in terms of the hole size it can produce effectively and the length of time needed to drill. In addition, the tooling cost is high. This paper reports on an investigation into a sequential laser and EDM micro-drilling technique for the manufacture of next generation fuel injection nozzles. A laser-drilled pilot hole is rimmed out by EDM drilling. It was found that this hybrid process has eliminated the problems of recast and heat affected zones typically associated with the laser drilling process. The new process has enabled a 70% reduction in total drilling time compared to standard EDM drilling as less material is removed by the EDM. The quality of the holes is as good as direct EDM drilling, thus eliminating the need for re-certification of the drilling process. Various combinations of laser/EDM drilling conditions have been examined. Optimum diameters for the pilot hole and the EDM electrode have been identified for a particular diameter of fuel injection nozzle, giving the minimum total drilling time and the best quality holes. A special system was designed to enable the alignment of nozzles to be controlled to within ± 20 μm. The technique has enabled valuable cost savings and increase in production capacity for next generation fuel injection nozzle manufacture.     

电火花技术在弹簧高精度端面加工中的应用研究

某航空飞行器的尾斜轴有一种弹簧,其两端面形位公差要求高。通过研究弹簧的特性及加工性能、电火花加工技术原理,结合电火花加工机床结构和功能特点,运用数控技术,探索采用电火花加工技术加工弹簧高精度端面,提出实施方案、采取的措施、解决问题的途径。应用结果表明:电火花加工方法可有效解决弹簧端面加工过程中的变形问题,能稳定可靠地保证弹簧端面高精度技术要求。目前此方法已成功运用在多种高精度端面弹簧的加工工艺上,完全满足用户需求,效果理想,具有重要的推广应用价值。