超声辅助电解磨削GH625微小孔工艺研究

超声振动辅助电解磨削加工技术是一种以超声振动作为辅助、电解磨削为主要加工方式实现零件精加工的新型加工技术。为获得更高表面质量的管电极微孔,首先利用单因素法对GH625材料进行管电极打孔,初步得到最小平均锥度0.043°的微小孔,然后通过正交试验研究脉冲电压、电解液浓度、主轴进给速度、阴极转速对加工微小孔锥度和表面质量的影响规律。结果表明:在脉冲电压7 V、电解液质量分数14%、阴极转速12000 r/min、进给速度0.7 mm/min下,可获得内表面粗糙度和平均锥度分别为Ra0.499μm与0.036°的微小孔。     

微细电解加工技术研究现状与展望

对近年来微细电解加工领域的研究现状和发展趋势进行了概述,包括微细电解加工的基础理论、微细电解加工技术和加工装置、影响因素与极间间隙检测控制,以及关键技术和今后的发展方向.     

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.     

基于润湿供液的电化学放电线切割实验研究

针对非导电硬脆材料的微细线切割加工,设计并搭建了基于润湿供液的电化学放电线切割装置,实现了对石英材料的有效切割,确定了实现电化学放电线切割加工的临界电压。通过提取加工过程中能反映极间状态的电流信号作为控制加工的依据,实现了对石英材料的可控加工,实验表明加工速率及槽宽随着电压的增加而增大。通过对工件步进进给和匀速进给两种加工方式的比较表明,利用电流信号作为进给控制依据进行步进进给能更好地保证加工的连续性。     

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).     

桌面式水平走丝微细电火花线切割机床的研制

利用直径小于80μm电极丝的微细电火花线切割加工技术,可加工出表面粗糙度好、尺寸精度高的微小复杂零件。以加工带有螺旋结构的微小复杂零件为目标,设计了一套桌面式水平走丝微细电火花线切割加工装置,主要包括具有人机界面、任务规划和运动控制的开放式数控系统,走丝平稳、张力可控的分体式水平走丝机构,以及精确可控微小放电能量的纳秒级脉冲电源。     

工件低频振动对微细电解加工材料蚀除速度的影响

基于电化学阳极溶解原理的微细电解加工技术在特种加工技术中占据着重要的地位。然而,微小间隙内电解液更新困难、电解产物难以及时有效排出,一直是制约该技术发展的瓶颈。利用自行设计的低频振动装置,通过工件低频振动辅助的方法进行微小孔电解加工实验,结果表明：该方法改善了加工区域的流场条件,促进了加工区域电解产物的输运及电解液的更新,显著提高了工件材料的蚀除速度。     

MA956高温合金活动模板电解加工小孔技术研究

对采用活动模板电解加工技术在MA956铁基高温合金薄板上加工小孔的工艺方法进行了讨论。研究了电解液温度、加工电压、电源占空比和脉冲频率等参数对小孔加工结果的影响。研究表明:采用10%w.t.NaNO_3电解液,在电解液温度为30℃、加工电压为40 V、电源占空比为30%、电源脉冲频率为400 Hz时,能在MA956高温合金薄板上加工获得锥度小的小孔。     

微细电解加工技术的概况与展望

概括总结了微细电解加工的典型技术,综合分析了近几年微细电解加工技术的研究成果和最新进展,包括脉冲电源、新型电解液、复合加工、微器件加工以及基础理论等方面,展望了其未来的研究重点和发展趋势.     

蜂窝状微坑结构的电化学加工研究

在摩擦副表面加工蜂窝状微坑作为改善滑动摩擦的途径已成为研究热点.研究了电解加工蜂窝状微坑结构的方法,介绍了加工原理和试验过程,分析了加工电压、加工时间、阴极贯穿孔尺寸、电解液等加工参数对所加工微坑的影响,优化了加工参数和加工条件,提高了所加工微坑的精度.     

Electrochemical micromachining using vibratile tungsten wire for high-aspect-ratio microstructures

Electrochemical micromachining can remove electrically conductive materials with the transferring of ions, so that high precision is achievable. A novel method for fabricating high-aspect-ratio microstructures by electrochemical micromachining using vibratile tungsten wire was proposed in this paper. The slight vibration of tungsten wire can improve the machining stability. The relations between the machining accuracy and machining parameters were experimentally studied. Micro groove with the width of 15 μm was machined, and micro sharp-angles structure with aspect ratio of 10 was obtained experimentally.     

Wire electrochemical discharge machining (WECDM) of quartz glass with titrated electrolyte flow

Electrochemical discharge machining (ECDM) is a promising technique with great potential for application to machining non-conductive brittle materials. In this study, wire electrochemical discharge machining (WECDM) was applied to processing quartz glass with electrolyte supplied in titrated flow. During WECDM, under surface tension and gravity, the electrolyte flows down in droplets, over the graphite auxiliary electrode and brass wire, producing oxygen and hydrogen bubbles, respectively. The fluid inside the droplet forms eddies on the two sides of the quartz, removing chips and electrolysis resultants. Rapid replenishment of electrolyte to constant concentration can ensure even distribution of current density and a stable insulation gas film can thus be formed. Experimental results show that quartz glass processed by WECDM with titrated electrolyte flow yielded long straight slits of small mean width. In addition, with the electrolyte supplied in droplets, less electrolyte is consumed in the process. The proposed droplet titration approach to WECDM of quartz glass incurs less cost and pollution, making it both cost effective and environmental friendly.     

Micropatterning of Ni-based metallic glass by pulsed wire electrochemical micro machining

The technique of wire electrochemical micro machining (WECMM) is proposed firstly for the micropatterning of Ni-based metallic glass in this paper. Metallic glass (MG) exhibits many outstanding properties such as high hardness and strength, which enable it to be used as functional and structural materials in micro electromechanical systems (MEMS). A significant limitation to the application of MGs is the challenge of shaping them on micro scale. WECMM is a non-traditional machining technique to fabricate microstructures that has some unique advantages over other methods, which will be a promising technique for micro shaping of metallic glass structures. Taking the example of a Ni-based glassy alloy, Ni₇₂Cr₁₉Si₇B₂, the polarization and fabrication characteristic in dilute hydrochloric acid electrolyte were investigated. Changes in the machined slit width in terms of several experimental parameters were investigated to find the optimal ones. Finally, the optimal machining parameters: HCl electrolyte concentration of 0.1 M, applied voltage of 4.5 V, pulse duration of 80 ns, pulse period of 3 μs and feed rate of 0.3 μm s⁻¹ were employed for the fabrication of microstructures. Such as a micro square helix with a slit width of 14.0 μm, standard deviation of 0.2 μm and total length up to 2000 μm, along with a micro pentagram structure with side length of 90 μm and sharp corner of 36°, were machined with a high level of stability and accuracy.     

A high efficiency electrochemical machining method of blisk channels

This paper presents an electrochemical machining method in which three stainless steel tubes as cathode tools move towards workpiece parts with space trajectories and electrolyte is ejected from the outlets of the tool tube walls to the workpiece to electrochemically produce three blisk channels simultaneously. The shape and structures of cathode tool tubes are optimized numerically and experimentally for distributing the electrolyte flow more uniformly. A special experimental system with synchronous motion of three tool tubes has been developed. Experimental results indicate that three channels can be produced at one time with good quality and high efficiency.     

掩膜电解微坑阵列对钛合金表面疏水性能的影响

为了提高钛合金表面的疏水性能,采用润湿理论模型与多物理场耦合仿真相结合的方法,建立接触角与掩膜电解加工工艺参数之间的直接映射关系,揭示微坑阵列掩膜电解加工对表面疏水性能的作用。建立接触角与微坑阵列几何尺寸间的表面疏水理论模型,对掩膜电解加工进行多物理场耦合仿真;理论模型与仿真结果相结合,获得了接触角与掩膜电解加工工艺参数之间的直接映射关系。此外,以表面接触角为因变量,以电解质质量分数、掩膜尺寸和电解电压为自变量,进行正交试验仿真和计算,获得了最佳工艺参数组合并进行试验验证。与仿真计算相比,试验测量得到的微坑阵列直径、间距、深度、表面接触角误差分别为2.49%、6.87%、7.40%、6.01%,从而表明该方法在未经低表面能材料修饰的情况下,成功制备接触角约为141°的微坑阵列疏水表面。     

铝合金表面微/纳米结构构筑研究进展

铝合金以其优异的性能而被广泛应用于工业生产的各个领域,通过一系列方法可以在铝合金表面构筑多种类型的微纳米结构。这些微纳米结构可以提高铝合金的摩擦学性能、耐蚀性能、界面结合力、抗结冰性以及装饰性能,对将铝合金应用到更广阔和更苛刻的环境中具有重要意义。介绍了铝合金表面微/纳结构的主要构筑方法。化学刻蚀法制备出了凸台和凹坑的迷宫形貌;阳极氧化法构筑出了高度有序的孔洞结构;微弧氧化法制备出了表面布满微孔的氧化膜;水热法可以构筑形状多样的纳米花朵形貌;电解加工对阴极材料的表面结构进行复刻,可以采用不同比例的阴阳极材料进行大面积的制备。阐述了这些微纳米结构的生长过程,并分析了实验条件(如温度、处理时间、电参数、溶液成分及浓度等因素)对铝合金表面微纳米二元结构生长的影响规律,重点总结分析了其研究现状和影响微纳米结构的因素。通过对现有铝合金表面结构制备方法的总结和分析,展望了其今后的发展趋势。     

脉冲振动电解加工对圆柱型面复制精度的影响

开展了不锈钢材料脉冲振动电解加工的试验研究,设计了试验所需的工装夹具、工具电极和电解液流场。采用圆柱型面的工具电极电解加工不锈钢工件,通过对比试验分析了直流匀速进给电解加工和脉冲振动电解加工的精度差异,并优化了加工参数,获得了较佳的进给速度和脉冲电流占空比。对比二种加工方式证明脉冲振动电解加工能有效提高电解加工精度。     

国际特种加工研究趋势——第17届国际电加工会议综述

对第17届国际电加工会议论文进行了综述．介绍了近年来国内外特种加工领域的最新研究进展。主要内容包括电火花加工（EDM）、线切割加工（WEDM）、电化学加工（ECM）、超声加工（USM）、微细加工、激光加工（LBM）及相关复合加工工艺的研究成果。     

基于渐变孔隙正极和叉指型流道主动式锂空气液流电池电化学性能理论研究

提出了具有渐变孔隙正极结构的主动式锂空气液流电池,利用溶液泵驱动电解液循环,结合渐变孔隙正极结构,强化电极内部Li^+和O2扩散和结合能力,减弱电极钝化。基于COMSOL Multiphysics 5.3,建立二维电化学模型,用Darcy定律、Butler-Volmer方程和组分输运公式描述在渐变孔隙正极结构(ε=0.55+αX等)下电极内部电解液流动、正负极电化学反应及电解液中Li^+和O2浓度场分布。由于Li2O2积聚在正极孔隙内,电极比表面积下降,采用Carman-Kozeny方程修正渗透率K。研究渐变孔隙率、压强差、氧气参数、正极厚度及动力学速率系数对该电池放电性能影响。结果表明:在放电电流密度0.1 mA/cm^2,电池比电容量是被动式结构的2.5倍;与ε=0.85-0.1X相比,采用ε=0.55+αX结构的电化学性能较佳;在放电电流密度0.1 mA/cm^2下,正极厚度为500^750μm,电池放电性能较好。     

整体叶盘电解旋转套料加工实验研究

为了提高整体叶盘的加工效率、降低加工成本,开展了整体叶盘扭曲叶片电解预加工实验研究。通过分析叶型结构及对电极片内孔尺寸进行理论计算,设计了整体式加工阴极,并针对TC17钛合金材料开展了加工实验。结果表明:采用整体式加工阴极的电解加工方法能一次性去除大部分金属,实现整体叶盘大扭曲叶片的小余量一次性成形加工,叶型单边最小余量为2 mm。