基于电化学加工技术的微小孔去毛刺实验研究

针对直径小于1 mm的微小孔内部边沿存在的毛刺难以去除的问题,利用电化学加工技术去除铝板上微小孔的毛刺,通过有限元分析毛刺周边的电流密度分布,设计电化学去毛刺实验装置和长度可调的阴极工具。实验研究了电解液种类、浓度和加工时间等工艺参数对毛刺的去除效果。结果表明,在最优选择参数的条件下,电化学加工技术可快速有效地去除微小孔内部边沿的毛刺。     

脉冲电化学齿轮齿面光整加工实验研究

将脉冲电化学加工原理应用于齿轮齿面光整加工，建立了移动式成形阴极脉冲电化学齿面光整加工实验装置；研究了工作电流密度、阴极移动速度、扫描次数、电解液流速等工艺参量对加工质量及效率的影响，获得了较优的工艺参数；以模数为3mm、齿数为33的直齿圆柱齿轮为实例进行了光整加工实验研究。结果表明，该工艺不仅能在短时间内将齿面粗糙度大幅度降低，而且能显著增加齿面的光亮性。     

电化学光整加工在螺旋锥齿轮中的应用研究

针对螺旋锥齿轮加工质量的现状,提出了面向螺旋锥齿轮机械式铣齿机的螺旋锥齿轮电化学光整加工工艺方法。通过分析成功应用的典型电化学光整工艺方法,解决了螺旋锥齿轮电化学光整加工实施中获得稳定、均匀极间电流场及电解液流场所涉及的阴极运动模式及阴极几何结构;同时,实验验证了该工艺方法的可行性。实验结果表明:在实验研究的条件下,在Gleason№16型万能铣齿机的一个精加工铣削周期内,螺旋锥齿轮齿面的表面粗糙度可达Ra0.1μm的水平,其加工精度可由DIN10级提高到DIN7级。     

电极丝横向振动对电火花线切割加工间隙影响规律研究

以提高电火花线切割加工效率为目的,分析了电火花线切割加工间隙对加工效率的影响,建立了电极丝横向振动数学模型,揭示了各工艺参数对电极丝振幅及加工间隙的影响规律。采用直径1mm的钼丝进行了加工实验,得到了峰值电流、脉冲宽度和脉冲频率等参数对电极丝振幅的影响规律。结果表明所建立的振动模型正确,可为优化电火花线切割加工间隙,从而提高其加工效率提供参考。     

高回转精度多阶柱状微电极电化学高效制备试验研究

为实现高回转精度多阶柱状微电极的高效加工,对多阶柱状电极电化学刻蚀过程进行了深入的研究与改进。首先,根据电化学刻蚀理论推导了加工电流对电极直径变化的影响规律;通过试验证明了电极旋转可提高电流变化速率及有效起始电流进而提高加工效率,定性分析了电极旋转对电极回转精度的影响,提出了分阶变转速高效加工高回转精度多阶柱状微电极的方法;通过试验分析了各加工参数(电极转速、加工电压和切断电流)对电极形状及尺寸的影响;最后,在优化后的加工参数下,成功加工得到末端直径小于15μm且同轴度误差在1μm以内的多阶柱状微电极,与常规电化学刻蚀工艺相比,显著提高了加工效率。试验证明旋转电化学刻蚀是一种能够较好地提高微电极加工效率及回转精度的新工艺。     

开槽宽度对遮蔽模板辅助电解线切割加工微沟槽的影响

针对微沟槽结构难以高效低成本加工的问题,提出一种遮蔽模板辅助电解线切割加工新工艺。利用开有槽道的绝缘模板遮蔽工件非加工表面,对加工区域进行电场屏蔽和流场改善,实现场域离散式电解线切割加工,有效提高微沟槽的尺寸精度和加工稳定性,又比一般掩膜电解加工的深宽比更高。仿真分析了不同开槽宽度的影响,设计了专用夹具,进行了工艺实验。结果表明:使用直径0.3 mm的电极丝进行电解线切割加工,当开槽宽度W≤1 mm时,遮蔽模板可有效改善沟槽精度和表面质量。利用开槽宽度为1 mm的遮蔽模板和0.3 mm直径的电极丝,成功地在不锈钢工件表面加工出了宽981 μm,深1 058 μm的微沟槽。     

窄缝精密电解加工的实验研究

通过在理论上分析窄缝电解加工中片状电极和丝状电极对加工间隙和流场分布的影响,提出了采用小直径丝状电极提高加工精度和改善加工稳定性的方法。文中分别进行了片状电极和丝状电极之间、不同直径丝状电极之间的窄缝电解加工对比试验。结果表明,小直径丝状电极可以减小电解液流过电极丝产生的涡流死水区,改善加工区内的电解液更新和电解产物的排除,提高加工精度和加工过程的稳定性。     

成形阴极脉冲电化学光整加工技术应用研究

针对将成形阴极脉冲电化学光整加工新工艺应用于V形槽工件的表面光整加工,讨论了影响实际应用中的流场、间隙、电场等关键技术问题及其解决方案.并以实际V形槽工件为例,进行脉冲电化学光整加工,得到了良好效果.实验证明,该工艺应用于V形槽表面的光整加工是成功的.     

脉冲电化学机械抛光工具设计及其应用

针对具有复杂曲面模具,设计了几种结构、形状的阴极工具,并利用这些工具,采用脉冲电化学机械抛光的方法,对其中一种模具进行了抛光实验。实验表明,脉冲电化学机械抛光是一种有效的镜面加工方法。本工艺的关键是如何使电化学作用与机械作用相匹配,以得到最佳去膜效果。     

微细工具电极在线制作技术及实验研究

本文提出了一种在线制作微型工具电极的新方法。该方法是基于电化学微加工,通过反复交换工具电极和工件的极性,进行相互加工获得与电化学微加工相适应的微型工具电极。由于该过程在线进行,因此可以避免因两次夹紧工具电极造成的位置误差和夹紧误差,并可以大大提高加工精度。该方法对于电化学展成微加工来说是非常重要的。通过实验,稳定的加工出了最小直径为20μm的工具电极。     

球头阴极电解铣磨加工TC4钛合金试验研究

采用直径6 mm的球头阴极,通过内喷液式的供液方式,对TC4钛合金进行电解铣磨加工粗精加工试验研究.结果表明:采用球头阴极可以实现底面为曲面的沟槽加工,电解铣磨加工方法可以对沟槽进行连续的粗精加工,实现TC4钛合金曲面沟槽的高效精密加工.     

Electrochemical machining analysis on grid cathode composed of square cells

During the electrochemical machining (ECM), the cathodes designed by the existing methods are mainly unitary cathodes, which can be only used to produce the workpieces with the same shapes. However, there are few researches on designing cathodes for machining the different workpieces with the different surfaces. This paper presents the grid cathode composed of the square cells to produce the workpieces with different shapes. Three types of the square cells, 2.5 mm′2.5 mm, 3 mm′3 mm, and 4 mm′4 mm, are utilized to construct the plane, the slant, and the blade cathode. The material of the cathode and the anode is CrNi 18 Ti 9 , and the ingredient of electrolyte is 15% NaCl and 15% NaNO 3 . The machining equilibrium machining current and time are acquired and analyzed, the machining process and the workpiece quality are compared between using the grid cathode and the unitary cathode. Moreover, the machining errors on the workpiece surface are measured and analyzed, and the error reasons are traced and discussed to obtain the better surface quality of the workpiece. The experiment and analysis results show that the grid cathode can be used to manufacture the workpieces with complex shapes in certain range of the error. The workpiece quality improves with the size of the square cell being reduced, and if the square element is small enough, the workpiece quality is almost equal to the one machined by the unitary cathode. The proposed research realizes a single cathode machining the different workpieces with the different surfaces.     

旋转超声电解复合加工小孔的仿真加工

为研究旋转超声电解复合加工小孔的成型过程,进行了旋转超声电解复合加工小孔试验,得到了不同加工时间孔的截面,并根据试验参数,进行了基于ANSYS的二维仿真加工和三维仿真加工。对小孔的入口直径、底面直径和加工深度进行了对比分析,结果表明由于三维仿真加工中采用了管电极,并考虑了电解加工中阴极超声高频振动对电解液电导率的影响,故其仿真结果更加接近试验值,间接证明了旋转超声电解复合加工小孔三维仿真加工的可靠性,展示了不同时刻的三维加工型腔,为旋转超声电解复合加工的成型过程和成型规律的研究提供了参考。     

渐开线内花键电解加工流场设计及工艺稳定性研究

为进一步提高渐开线内花键电解加工的工艺稳定性,基于数值分析方法探讨了电解液流动方式、工具阴极结构、电解液参数对流场分布的影响规律。数值分析结果表明：电解液侧向流动可以改善加工区入口处电解液流速分布均匀性;带有导流段的变截面阴极能够降低工件表面流速波动。针对工艺稳定性及加工定域性,开展了渐开线内花键电解加工试验研究。试验结果表明：进给速度可达2.1 mm/min以上,齿形误差可控制在0.015 mm以内,当加工深度为30 mm时,齿向误差在0.02 mm以内。该加工方式的效率及精度能够满足很多实际需求,具有明显的技术经济优势。     

超声电解复合加工小孔工艺试验研究

为了研究超声电解复合加工难加工材料上小孔工艺,在8 mm厚的不锈钢1Cr18Ni9Ti上进行通孔加工试验。通过正交试验研究了电压、初始间隙、阴极转速和进给速度对小孔直径和表面粗糙度的影响,运用综合平衡法得出最优组合是:电压7 V、初始间隙0.2 mm、阴极转速1 600 r/min、进给速度1.6 mm/min。     

A study of supersonic-aided electrolysis

In this study, a composite processing technology combined with supersonic and electrochemical machining is adapted to etch copper. Rod copper of diameter 3.0 mm is selected as a sample material. A series of experiments of supersonic-aided electrolysis by agitating anode, and electrolyte were carried out to investigate performance for copper etching. Faster metal removal rate can be achieved in supersonic-aided electrolysis machining by agitating either the anode or electrolyte. Removal rate can be raised up to 65% by supersonic-aided electrolysis by agitation both of anode and electrolyte. Deposition speed of cathode is lower in supersonic-aided electrolysis. Machined surface roughness of workpiece by supersonic-aided electrolysis is much better than no agitation.     

阶梯孔数控电解镗孔加工的阴极设计及试验研究

NC electrochemical boring method was adopted to solve the processing problems of stepped inner holes with small inlet,large inner cavity,and large deep diameter ratio.According to the structural characteristics of stepped holes,cathodes with different spiral outlets,different rotating angles,and different taper of shunt blocks were designed.The flow fields were analyzed by FLUENT,and the results show that the cathodes with 24° conical angle,360° rotating angle,and double spiral outlets meet the design requirements.Orthogonal tests were carried out to study the influences of processing parameters on removal amount and processing clearance.Main size of the cathode is determined by the testing results,and the problems of uneven wall thickness of the stepped hole are solved by correcting the tapers of the cathodes.By the proposed method,errors of the stepped hole are small,and quality of processing surfaces is good,which meet the production requirements.     

Utilization of flow field simulations for cathode design in electrochemical machining of aerospace engine blisk channels

Electrochemical machining (ECM) cathode flow field design is crucial to machining aerospace engine blisk channels. In order to reduce the cathode design cycle and cost in machining, 3D cathodes and flow field simulation model were developed to facilitate analysis the flow fields in reversed flow patterns. The electrolyte flow line was determined by the distributions of electrolyte pressure, the diameter of the back orifice, and the areas of the back orifices in locations A, B, and C. The simulation results were utilized to analyze the influence of the electrolyte flow line. To verify the accuracy of the simulation, the experiments were carried out. The simulation results were consistent with the experiment data. It indicates that electrolyte flow field simulation is an effective method to optimize cathode design. Utilizing this methodology can improve the ECM cathode design efficiency and reduce cathode revision time.     

钛合金深窄槽可控振动辅助电解加工试验研究

为提高TB6钛合金深窄槽电解加工精度,基于电场仿真分析方法,研究了不同加工方式深窄槽侧壁电流密度和电化学溶解速度分布规律,并采用工艺试验方法对持续进给、振动进给、脉冲与振动耦合3种加工方式进行对比研究。试验结果表明：振动频率和持续进给速度固定时,提高振幅能够显著降低槽宽标准差,提高深窄槽加工一致性;持续进给速度相同时,脉冲与振动耦合的平均槽宽和槽宽标准差均较小,加工精度更高。采用脉冲与振动耦合加工方式,深窄槽入口处平均槽宽为2.62 mm,沿深度方向平均槽宽为2.73 mm,入口处槽宽标准差为0.05 mm,沿深度方向槽宽标准差为0.03 mm。     

Selective and localized embrittlement of metal by cathodic hydrogenation utilizing electrochemical jet

Electrochemical jet processing (EJP) is an easy-to-implement technology for creating complex microstructures based on anodic dissolution without requiring specially designed cathodes. In this study, a new electrolyte-jet-based surface modification method based on the principle of cathodic hydrogenation, namely, electrochemical jet hydrogenation (EJH), was proposed for the first time to selectively modify the material in aspects of its brittleness. In this method, a workpiece is innovatively set as the cathode, and hydrogen evolution occurs locally on the cathode surface within the jet impinging area, leading to a localized H-treatment of the cathode material. The hydrogen-material interaction can alter the surface material property and result in localized surface modification, for example, material ductile-brittle transition by hydrogen embrittlement (HE). In this research, the proposed method was validated on niobium metal. According to the results, evident localized embrittlement was achieved, and the degree of embrittlement was precisely controlled by adjusting the electrochemical parameters mainly including current density and processing time. As a selective surface modification method, EJH can be applied as an assistive technology in hybrid machining of difficult-to-machine superalloys where localized surface modification of ductile-brittle transition is expected.