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.     

微细电极精密车削技术

对微细电极的精密车削工艺进行了研究，用人造金刚石刀具，加工出直径φ7μm的微细电极，用车削的φ11μm微细电极成功地加工出φ19μm的微细孔。研究结果表明，在微细电极的加工中，切削用量不仅对电极表面质量产生影响，而且关系到能否车削成功。     

组合式微细电火花电极制作工艺试验研究

针对块电极磨削效率高和线电极磨削(WEDG)精度高的优点,采用块电极磨削和线电极磨削相结合的方法,在多模式脉冲电源下制定了块电极磨削作为粗磨削、线电极磨削作为中、精磨削的微细电火花电极制作工艺流程。采用去离子水作为工作液,分别对块电极磨削和线电极磨削进行了电源模式和电参数试验,分析试验结果,总结出一组适合于粗、中、精磨削的电参数组合,研究出一套加工效率高、精度高且直径一致性高的电极制作工艺方法。并通过试验验证了该工艺方法能稳定加工出长径比大于16的微细电极,利用其加工出了256个直径小于50μm、直径偏差在2μm内的微细阵列孔。     

高精度微细电火花加工系统的研制

设计并研制了一个微细电火花加工系统。该系统主要由横轴布局V型陶瓷结构旋转主轴系统、带有压电陶瓷的宏、微伺服进给系统、制作微细工具的反拷系统和读数显微镜及电气控制等部分组成，应用该系统已成功地加工出了直径仅为φ4．5μm的微细轴和直径仅为φ8μm的微小孔。     

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。     

微细孔、阵列孔及微细三维型腔的超声加工研究

利用自行开发的微细电火花与微细超声复合加工装置,对微孔超声加工中效率随孔深的变化、磨料颗粒尺寸对精度的影响等进行了实验研究,并采用恒加工力控制方式,在单晶硅100晶面实际完成了直径18μm圆孔和28μm×28μm方孔的超声加工、微细十字孔与阵列孔的超声反拷加工以及微细三维型腔的工具均匀损耗补偿分层铣削超声加工.     

横轴布局微细电火花加工机床

介绍了作者研制的微细电火花加工实验样机及部分实验结果。该机床采用横轴布局的主轴结构；应用了先进的线电极电火花磨削法制作微细轴；采用了驰张式微能放电电源；以去离子水作为加工工作液。经实验，加工出了部分微细轴和微孔。     

绝缘陶瓷电火花磨削加工的研究

针对绝缘陶瓷的磨削加工问题，提出了基于绝缘陶瓷辅助电火花加工原理的绝缘陶瓷电火花磨削加工方法。介绍了绝缘陶瓷材料的电火花磨削加工原理，对绝缘陶瓷Si3N4进行了电火花磨削加工工艺试验，研究了电参数对绝缘陶瓷Si3N4电火花磨削加工速度的影响，进行了微细轴电火花磨削加工试验，加工出了直径1mm的Si3N4绝缘陶瓷微细轴。     

微喷部件阵列孔电火花加工工艺试验研究

比较各种微细阵列孔的电火花加工方法,分析了单电极加工微细阵列孔方法的优点。以去离子水作为工作液,在已研制成功的微喷部件阵列孔电火花加工机床上进行单电极加工微细阵列孔的工艺试验,研究电源参数对微细阵列孔的孔径一致性、加工效率及电极损耗的影响规律。优化微细阵列孔加工的电参数,实现稳定的一次性加工256个直径小于50μm、偏差小于2μm的微细阵列孔。     

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。     

微细电极的正交点电接触在线测量及组合制作工艺

为服务于微细电火花加工用微细工具电极在线制作,提出一种正交点电接触标准细棒的微细电极在线测量方法。将电极轴线与标准细棒轴线正交（垂直）布置,通过电极外径与标准细棒外径之间低压电感知的点接触方式,避免或减少标准棒尺寸误差和安装误差的影响。提出采用自穿孔成形伺服反拷法和线电极磨削法组合工艺,并结合在线测量反馈方式,实现了钨材料微细电极较高效率的在线制作,尺寸可控精度可达±1．5μm。     

微铣刀制备技术与实验研究

微铣刀制备技术是微细铣削的关键技术之一,对微细铣削加工出的微小零部件的特征尺寸和表面质量有重要影响。从微铣刀具的材料与涂层及其制造工艺两方面,对微铣刀制备技术进行了介绍,并通过线电极电火花磨削方法制备了刀头直径为100μm的微铣刀,初步验证了基于自研μEM-200CDS2微细组合电加工机床开展微铣刀在位制备的能力。     

Micro Electrochemical Machining of 3D Micro Structure Using Dilute Sulfuric Acid

Micro electrochemical machining (ECM) using ultra short pulses with tens of nanosecond duration is presented. 0.1 M sulfuric acid was used as electrolyte and 3D micro structures were machined on stainless steel. To prevent taper, a disk-type electrode was introduced. Using the disk-type electrode, taper could be eliminated. To improve productivity, multiple electrodes were applied and multiple structures were machined simultaneously. Since the wear of tool electrode is negligible in ECM, micro wire can be used as tool electrode. Using a platinum wire electrode with 10 urn diameter, various 3D features were machined on stainless steel plate.     

Micro electrochemical machining for complex internal micro features

In this paper, the application of micro electrochemical machining (ECM) for the micromachining of internal features is investigated. By controlling pulse conditions and machining time, micro features are machined on the side wall of a micro hole. These methods can easily machine a micro hole with larger internal diameters than the entrance diameter, which is very difficult to do by the conventional processes. A micro disk-shaped electrode with an insulating layer on its surface is also introduced to machine microgrooves inside the hole. This method is similar to the turning lathe process. The purpose of this study was to confirm the various possibilities of making complex internal structures in a micro hole by micro ECM.     

基于静电喷雾的金刚石磨粒微表面均布特性研究

目的改善精密/超精密成形磨削中砂轮存在磨粒分布不均匀的问题。方法仿真分析针-环电极空间电场强度的分布特性,以及喷嘴轴线上场强随喷嘴直径、环状电极直径、电极间距的变化规律。金刚石磨粒均匀分散在静电喷雾溶液中,在高压电场和压力泵的作用下将喷出形成微表面。通过网格分析法和截距法定量分析金刚石颗粒微表面分布的均匀性。结果针-环电极产生的空间电场是对称分布的,电场线集中分布在喷嘴附近,其电场强度沿轴线向外急剧降低。由于尖端效应,喷嘴直径减小,其尖端处的电场强度明显增大;电极间距增大,喷嘴处的场强降低。网格计数法中,网格划分得越细,微表面颗粒分布偏差越大,即分布均匀性越差,但更能反映真实的颗粒整体分布情况,且各偏差曲线分布的趋势基本相同,仅在液体流量20 m L/h处出现了与理论的变化规律不符合的情况。截距法中,当液体流量增大时,颗粒间距离偏差值逐渐降低,且在液体流量20 m L/h处明显下降。结论在金刚石颗粒微表面分布的定量化分析中,网格计数法只能体现区域分布的均匀性,而对某块区域内颗粒的距离不敏感,无法区分颗粒聚集的情况,导致计算结果出现偏差。截距法则对颗粒的间距比较敏感,因此有效地结合网格计算法和截距法可以对金刚石磨粒的分布情况做出准确分析。     

Tribological behavior of micro structured surfaces for micro forming tools

Mechanical micro machining processes, like milling and grinding are appropriate technologies for the flexible production of precise molds with complex shapes for metal forming processes. In most cases machining strategies are orientated towards form accuracy of the desired forming tool only. Thus, the generation of tribologically advantageous surfaces is often carried out in subsequent machining steps like honing. In micro scale the subsequent treatment of complex surfaces is very difficult. For that reason it is desirable to create the shape and a suitable surface texture with one tool in one step.This paper is focusing on the comparison of the tribological behavior of polished surfaces with structured surfaces machined by micro milling and micro grinding processes. Micro milling tools and grinding pins with ballend shape are used to create micro structured surfaces. The machining strategy (tool path and line pitch) was varied for both tool types in the same manner. The experiments were carried out on hardened cold working steel using tungsten carbide micro cutters with TiAlN coating and micro grinding pins with an abrasive diamond layer. White light interferometry was used to characterize the machined surfaces and determine the surface parameters. Moreover, a strip drawing test was set up to investigate the tribological behavior of the system consisting of the machined surfaces and thin sheet metals. The results of the strip drawing test suggest a relationship between micro structure and tribological behavior. Finally, the dependencies between machining technology, surface parameters and tribological behavior will be discussed.     

Abrasive processes for micro parts and structures

The demand for miniaturized products and functionalized parts is increasing, and many such products are made of hard and brittle materials machined by abrasive processes. The first part of this keynote paper is dedicated to a discussion of micro parts and micro structures machined – at least in part – by abrasive processes, followed by a discussion of the associated abrasive processes. The strengths and limitations of these processes, among which include dicing, micro grinding, micro abrasive blasting, and vibration and magnet field assisted finishing are discussed. The paper concludes with a discussion of future trends in the field.     

车用螺纹磨具优化设计

详细介绍了车用螺纹磨具的设计原理。用该磨具加工的轧机拉杆完全符合用户技术条件要求。     

Application of micro-EDM combined with high-frequency dither grinding to micro-hole machining

This research presents a novel process using micro electro-discharge machining (micro-EDM) combined with high-frequency dither grinding (HFDG) to improve the surface roughness of micro-holes. Micro-EDM is a well-established machining option for manufacturing geometrically complex small parts (diameter under 100 μm) of hard or super-tough materials. However, micro-EDM causes the recast layer formed on the machined surface to become covered with discharge craters and micro-cracks, resulting in poor surface quality. This affects the diameter of the micro-hole machined and undermines seriously the precision of the geometric shape. The proposed method that combines micro-EDM process with HFDG is applied to machining high-nickel alloy. As observed in SEM photographs and surface roughness measurement, HFDG method can reduce surface roughness from 2.12 to 0.85 μm Rmax with micro-cracks eliminated. Our results demonstrated that micro-holes fabricated by micro-EDM at peak current 500 mA followed by HFDG at 40 V can achieve precise shape and good surface quality after 6–8 min of lapping.