共查询到19条相似文献,搜索用时 468 毫秒
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将超声振动技术应用于微细孔的电解加工中,以排除间隙内的加工产物,然而,超声空化现象产生的冲击力会影响电极表面的绝缘层,并加速其破坏。为提高侧壁绝缘电极的使用寿命,采用微弧氧化和阴极电泳工艺在微细钛电极表面形成由陶瓷膜和电泳漆膜组成的双绝缘层。通过超声振动辅助微细孔电解加工实验,对电极侧壁双绝缘层的耐久性进行验证,并分析了超声振动功率、电解液浓度和加工电压对双膜侧壁绝缘电极微细孔加工精度的影响。实验表明:双绝缘层电极在超声辅助微细孔电解加工中显示了很强的绝缘耐久性;当超声振动功率超过一定值后,微细孔电解加工能稳定进行,之后,随着功率的增加,孔的精度改善很小。在稳定加工中,需降低电解液浓度和加工电压,从而减小杂散腐蚀,保证加工孔的形状精度。 相似文献
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本文对电解加工误差的主要组成部分——遗传误差,进行了比较全面的分析。文中着重分析了提高去除速度比以减小遗传误差的三条主要途径: 1.选用合适的钝性电解液,以改善电流效率特性,从阳极膜与电流效率的相互关系中,寻求阳极/电解液的合理匹配,利用过钝化区阳极膜特征的变化,获得良好的电流效率特性。 2.采用混气电解加工,以改善电导特性。通过设计合理的混合腔和选用适量的气、液流量,使加工间隙内的气液混合比获得合理的分布,保证良好的电导特性。 3.采用高速进给,以实现小间隙加工。通过改进设备条件和精心设计阴极,缓和加工间隙小与电流密度大的矛盾,使进给速度大幅度提高,从而实现小间隙加工。电解加工过程是在小间隙、大电流密度、高电解液流速和强电解质溶液的特定条件下,在工件阳极和电解液的界面上所进行的阳极溶解过程。由于阳极溶解的需要及其结果,在工件和工具电极之间存在着加工间隙。同时,由于影响阳极溶解的因素很多,且其变化规律又较复杂,致使加工间隙也随之变化多端。这种加工间隙的存在及其变化,就是电解加工误差的主要来源。因此,加工误差实质上是工件表面上阳极溶解不均匀性的宏观反映。对加工误差的分析,必须连系阳极溶解过程的本质,及其伴生的加工间隙,才能逐步认识其变化规律,寻求提高电解加工精度的有效途径。电解加工的综合误差是由四方面误差组成: (1)遗传误差:由于毛坯余量不均匀而产生的误差; (2)复制误差:由于加工间隙不均匀而产生的误差; (3)重复误差:由于加工间隙不稳定而产生的误差; (4)工具误差:由于工具型面不正确而产生的误差。本文试就遗传误差问题作简要分析。 相似文献
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Accurate prediction of electrode shapes is most important in electrochemical manufacturing process which includes electrochemical machining and electroforming. In the former process, the electrode design is focused on the prediction of the cathode tool which significantly affects the machining accuracy. In the electroforming process, the anode electrode shape determines the current density distribution and so the properties of the deposited metal. This paper proposes a finite element approach to accurately determine these electrode profiles. The proposed method does not require Iterative redesign process, therefore provides excellent convergence and efficient computing. Close agreements between theoretical and experimental results have been observed. 相似文献
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R. Thanigaivelan R. Senthilkumar R. M. Arunachalam N. Natarajan 《Surface Engineering and Applied Electrochemistry》2017,53(5):486-492
To make use of the full capability of electrochemical micro-machining (EMM), a meticulous research is needed to improve the material removal, surface quality and accuracy by optimizing various EMM process parameters. Keeping this in view, an indigenous development of an EMM machine set-up has been considered to carry out a systematic research for achieving a satisfactory control on the EMM process parameters to meet the micromachining requirements. In this study an EMM machine has been developed and experiments were conducted to study the influence of some of the major process parameters such as the machining voltage, electrolyte concentrations, the pulse-on-time and the machining current on the machining rate and accuracy. The effect of the shape of the tool electrode tips on EMM has been investigated experimentally with 304 stainless steel sheets. The machining rate and the overcut are significantly influenced by the shape of the tool electrode tip. 相似文献
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In micro wire electrochemical machining, the machining gap between the cathode wire and anode workpiece is so tiny that it is difficult to remove electrolysis products and renew electrolyte, leading to frequent electric short circuits and quite low processing speed. Three approaches of enhancing mass transport, electrolyte flushing along the wire, wire traveling in one direction and micro-vibration of cathode wire have been studied theoretically and experimentally in this paper. The results demonstrate that the proposed methods significantly enhance the mass transport and thus improve the machining stability, the productivity and the surface quality for micro wire electrochemical machining. 相似文献
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Se Hwan Choi Bo Hyun Kim Hong Shik Shin Do Kwan Chung Chong Nam Chu 《Journal of Materials Processing Technology》2013,213(4):621-630
Micro electrochemical machining (ECM) of tungsten carbide with cobalt binder (WC–Co) was studied using ultrashort pulses. In ECM, the machining characteristics were investigated according to machining conditions such as electrolyte, workpiece potential, and applied voltage pulse. Using a mixture of sulfuric acid and nitric acid, microstructures with a sharp edge and good surface quality were machined on tungsten carbide alloy. The potentials of workpiece electrode and tool electrode were determined by considering the machining rate, machining stability, and surface quality of products. With the negative potential of the workpiece electrode, oxide formation was successfully prevented and shape with good surface quality in the range from Ra 0.069 μm to 0.075 μm were obtained by electrochemical machining. Moreover, the performance of ECM, which includes machining gap, tapering, surface roughness, and machining time, without tool wear was compared with that of electrical discharge machining (EDM). Microstructures of WC–Co with a sharp edge and good surface quality were obtained by electrochemical milling and electrochemical drilling. Micro electrochemical turning was also introduced to fabricate micro shafts. 相似文献
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深窄槽结构具有尺寸小、深宽比较大的特点,狭小的加工区域存在排屑不畅、散热效果差等问题。为解决深窄槽加工过程中排屑困难的问题,提出通过优化电极结构来提升深窄槽短电弧-电化学复合加工的稳定性。分别设计单孔、多孔及螺旋3种管状电极结构,对不同电极结构加工时的间隙流场状态进行仿真研究。对比不同电极结构极间介质流速与压力的分布状态,并对仿真结果进行实验验证,探究电极结构对短电弧-电化学复合加工性能包括加工效率、尺寸精度、表面质量等指标的影响。实验结果表明:螺旋电极结构相比于单孔电极和多孔电极更能改善极间的流场状态,在保证深窄槽尺寸精度的情况下提高了加工效率与表面质量。 相似文献
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液氧煤油火箭发动机燃气弯管具有尺寸较大、形状特殊的三维空间弧面结构,利用传统拷贝式电解加工技术难以获得理想的加工形貌。针对弧面结构燃气弯管的加工难点,研究采用电解铣削技术进行加工,基于新一代液氧煤油火箭发动机燃气弯管的尺寸等比缩小样件,试验了具有弧面结构的316L不锈钢在NaCl溶液中不同工艺参数下的电解铣削加工特性。结果表明:在电压40 V、加工间隙0.3 mm、电极扫描速度20 mm/min的加工参数下可得到表面形貌良好的90°圆弧面工件,初步验证了电解铣削技术进行宏观尺度弧面结构的加工可行性。 相似文献
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