反拷法精确制作大长径比微细电极的工艺探索

电火花反拷法是一种传统的微细电极在线制作方法,其优点是加工效率高,不存在重复定位误差;缺点是电极尺寸不易控制,容易存在锥度误差。通过对放电参数、电极材料和进给方式的优化,解决了在普通电火花机床采用反拷法在线加工微细电极的锥度问题。结合机床实际,详细叙述了耐磨损微细电极制造的工艺优化过程和实际使用性能,为微细电极的加工和使用提供了完整的工艺参考,并成功加工出直径φ0.1 mm、长径比达66的耐磨损电极。     

微细电火花加工中的电极在线制作与检测

将反拷块与线电极电火花磨削（ＷＥＤＧ）装置相结合，成功地实现了微细电极的高效、高精度在线制作 。充分利用机床的数控功能和接触感知功能以及标准量块和ＷＥＤＧ装置，在不增加任何测量附件的情况下，实现了微细电极的锥度及尺寸测量。     

三轴机床微细异型电极加工与尺寸误差分析

采用直线插补与圆弧插补算法,在三轴卧式微细电火花机床上加工出圆锥台、四棱台以及带有圆弧曲面的微细异型电极,并对加工结果尺寸误差及导致误差产生的原因进行了全面分析。结果表明,微细异型电极的尺寸误差均在2%以内,而放电间隙的随机性、机床运动精度、尺寸测量精度等均是导致误差形成的原因。     

微细电火花制备大长径比微细电极的工艺研究

针对电火花块电极磨削效率高和线电极磨削精度高的优点,采用块电极磨削为微细电极的粗磨削、线电极磨削为微细电极的中、精磨削方式,对大长径比微细电极的制作技术进行研究。通过分析微细电火花加工大长径比微细电极的影响因素,对影响大长径比微细电极制作的加工参数进行了大量的工艺试验,得到各参数对微细电极制作的影响规律,优选得到相关的大长径比微细电极的加工参数,并进行了实验验证。     

基于微细电火花加工技术的微冲裁模具在线制备

针对微冲裁异形截面的微小模具难以制备及安装对准的问题,利用微细电火花三维铣削加工技术加工反拷贝电极及凹模,利用所加工的反拷贝电极通过电火花反拷贝加工技术加工凸模,整个工艺过程在线制作,避免了凸凹模具二次装夹产生的位置误差。该工艺分别在线制作凸凹模具,实现了复杂截面形状微型模具制备和在线对准。通过设计试加工实验确定加工参数,并利用该工艺成功制作了一套截面形状复杂的具有微小特征结构的高精度微冲裁模具。     

电火花微细电极标准球在线检测方法

设计了标准球电极在线测量系统,它由标准球、支杆及待测电极构成。介绍了测量系统的使用方法,并对其测量误差进行了分析。做了块状电极反拷测量试验,结果表明:系统能准确有效地对电火花微细电极进行在线测量,测量值与非接触式三坐标测量机离线测量值的相对误差小于5%,从而实现了电火花加工微细电极简单、快捷的在线测量。     

基于LIGA技术的微细电火花加工优化研究

比较了活动掩膜法与固定掩膜法得到的PMMA胶结构,实验表明固定掩膜法更适合于多次曝光.结合LIGA技术和微细电火花加工的优点,用LIGA技术制备出具有复杂形状的铜微细工具电极,再用该工具电极进行微细电火花加工,在不锈钢上加工出异形微细孔.并通过进一步调整电火花加工工艺参数,优化了加工尺寸精度和表面粗糙度.     

微细铣削不锈钢微型薄壁试验研究

针对不锈钢微型薄壁的尺寸精度与表面质量,基于正交试验方法,文章通过微细铣削参数与工艺的试验研究,分析出3个关键铣削参数(每齿进给量f_z、径向切深a_e、轴向切深a_p)对切削力、薄壁尺寸误差以及表面粗糙度的影响主次,识别出获得较好薄壁尺寸精度与表面质量的最优参数组合。研究结果表明,微细铣削不锈钢材料时,切削力所引起微细刀具的退刀量使薄壁的实际尺寸增大,适当多次下刀可以使薄壁尺寸减小,即重复定位对尺寸误差的影响可以抵消一部分刀具退刀量对尺寸误差的影响。这对加工不锈钢薄壁零件的参数选择以及后续微细铣削薄壁研究有实际的参考价值。     

微细型腔的数控电火花加工

微细型腔的数控电火花加工沈洪，陈杨文微细型腔是指尺寸在毫米规圆内的型腔。加工难点是：电极制造困难，电极定位困难，加工尺寸精度控制困难。如图１所示型腔，又细又长，合模精度要求高，模极为４０Ｃｒ淬硬ＨＲＣ５０。机加工是不可能的。如此细长的电极即使车出来，...     

UV-LIGA制作微细群电极工艺研究

微细电火花加工和微细电解加工是当前微细加工领域的研究热点,利用微细群电极进行微细加工可显著提高加工效率.研究了UV-LIGA制作微工具电极的技术.以金属为基底,采用UV-LIGA工艺来制作微细群电极,改进了前烘、后烘、显影等工艺参数,分别在铜和不锈钢基底上通过注射式倒胶的方法制作出厚度达1 mm的SU-8胶结构,最大深宽比达10∶1,并通过微细电铸,获得了铜微细电极.     

微细电火花伺服扫描加工实验研究

进行微细电火花三维扫描加工时,由于电极损耗相对严重,导致形位公差难以保证和加工效率较低。该研究分析了电火花加工常规的电极损耗补偿方法,提出了基于放电间隙伺服控制进行电极损耗实时补偿的微细电火花三维扫描加工方法。辅助以电极电接触感知工件平面和加工原点,三维结构加工实验显示,采用间隙伺服控制进行电极损耗实时补偿有利于提高扫描加工微三维结构的形位精度和加工效率。     

用块电极轴向进给法电火花磨削微细轴

对电火花磨削微细轴中的关键问题进行了分析，提出并研究了利用块状电极轴向进给磨削微细轴的方法。在自行研制的多功能微细加工装置上，用该方法加工出了直径10μm的微细轴，并用此轴加工出了直径20／μm的微细孔。实验中发现：令伺服响应延时，可改善微细轴的圆度。用此方法得到的微细轴，根部强度高，有利于微细轴的加工和工作。     

Machining of micro rotational parts by wire electrical discharge grinding

Micro rotational parts are used in several industrial sectors. Well-known applications are micro shafts of gears, ejector pins in forming tools, pin electrodes for micro electrical discharge drilling or micro stamping dies. Depending on the geometrical complexity of micro rotational parts different process variants of micro electrical discharge machining characterized by a rotating work piece can be used: wire electrical discharge grinding (WEDG) with fine wire electrodes, electrical discharge turning (EDT) with micro structured tool electrode, cylindrical electrical discharge grinding (CEDG) with micro profiled disk electrode. Characteristic to these process variants is the superimposed relative motion between the rotating electrodes and the feed. This relative motion can be varied in a wide circumferential velocity range to improve the material removal process. The paper gives an overview of kinematic and technological restrictions and requirements of the WEDG process influencing the process behavior with respect to the technological requirements of micromachining.     

EDM turning using a strip electrode

Turning by electrical discharge machining (EDM turning) is an effective method to machine hard-to-cut materials. Generally, a wire-EDM is utilized in EDM turning because it is not concerned with electrode wear. However, wire-EDM turning has a slow machining speed due to its small machining area, and the wire may break due to overheating electrodes. For these reasons, its machining speed must be limited. In this study, a strip-EDM was created in an effort to overcome the problems in the EDM-turning process. This machining method used a conductive strip as an electrode. The strip was fed continuously, like a wire-EDM; therefore electrode wear was not a concern. One advantage of the strip-EDM was that it increased the material removal rate because of its large machining area and non-breaking electrode. In the experiments, machining characteristics were investigated according to machining conditions, and practical machining was carried out via fabrication of complex shapes on a shaft workpiece.     

气中微细电火花沉积加工的单脉冲放电过程热力学仿真(英文)

建立气中微细电火花沉积加工过程电极材料的热物理模型。利用有限元分析软件ANSYS对单脉冲条件下的工具电极和工件的瞬态温度场进行数值模拟,分析热源形式、初始边界条件和放电能量分配对工具电极和工件材料蚀除形式的影响,并预测适合微细电火花沉积加工的工艺参数。采用仿真预测得到的工艺参数,在高速钢工具表面稳定沉积出直径约200μm、高度约1.2mm的微圆柱结构。对沉积材料微观组织结构的测试分析表明,沉积材料与基体结合紧密。工艺实验和测试分析证明了所建立的微细电火花沉积加工过程的单脉冲放电热物理模型和有限元求解过程的正确性。     

Debris and consequences in micro electric discharge machining of micro-holes

The tip shape of a blind micro-hole produced using micro electrical discharge machining varies with respect to the process parameters used during machining. The usual tip shape is a blunt geometry within the common range of applications, however, under specific machining conditions and machining depths, the tip shape changes drastically to an inverted concaved shape. The origin of such tip deformation in micro electric discharge machining of blind micro-holes was investigated. It was observed that debris particles produced during machining accumulated at the tip, formed a hill and functioned as a tool electrode especially when using fine machining conditions. The phenomena is elaborated experimentally with the affecting parameters to describe the wear mechanism. Open gap voltage, pulse energy and tool rotation speed are examined as varying parameters during the experiments.     

High-speed EDM milling with moving electric arcs

A novel high-speed electrical discharge machining (EDM) milling method using moving electric arcs has been proposed in this study. We connected a copper electrode rotating rapidly around its axis and a work piece to a DC power supply to generate a moving electric arc. To ensure high relative speed of any point on the electrode with respect to the work piece, the electrode was shaped like a pipe. It was observed that the electric arcs move rapidly within the discharge gap due to the revolution of the tool electrode, removing the materials on the electrode along the track of the arc roots. To explore the characteristics of machining with moving electric arcs, an EDM milling apparatus was devised. Two planes with approximately the same roughness were machined separately by this equipment and a traditional EDM machine for comparison. It was found that a much higher material removal rate can be easily achieved by EDM milling with moving electric arcs. In the meanwhile, wear of the tool electrode in this new method is negligible, which is greatly favorable for machining accuracy. The microstructures of these surfaces were also investigated for further information.     

整体叶轮电火花加工电极的成形电铸

电火花加工是整体叶轮的主要加工工艺方法之一,其中工具电极的制造是关键.研究了采用电铸技术制备电火花加工工具电极.由于电极结构复杂,电沉积时电场发生畸变,导致阴极表面的电场分布极不均匀,侧壁与底部结合处的电流密度远小于阴极表面其他地方的电流密度,针对这种情况,通过增加辅助阳极、屏蔽侧面等改善措施,成功制备了工具电极.     

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.