共查询到19条相似文献,搜索用时 171 毫秒
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掩膜电解加工技术是一种用于阵列结构加工的高效电化学加工技术,被广泛应用于各类难加工材料的阵列群孔、群坑或群槽的加工制造。目前,掩膜电解加工中多采用侧面单向供给电解液的方式进行加工,该冲液方式简单易行,但由于加工区迎水面和背水面的流场差异,造成群孔结构的成形精度较差。为此,提出了周期性换向冲液技术,以改善加工区流场分布,进而提升群孔结构的成形精度。通过数值模拟仿真和实验研究,明确了最佳的换向冲液频率,研究结果表明换向冲液技术可以有效提升孔的成形精度。最终,采用周期性换向冲液技术完成了阵列群孔结构的加工,相较于单向冲液,孔的侧壁与轴线夹角差异率下降至1%以内,获得了较高的成形精度。 相似文献
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微细电解线切割是一种新型的微细加工技术,适合高精度金属窄缝、窄槽等微细结构的加工,由于加工间隙内电解产物排出困难,容易影响加工精度。为了提高产物排出效率,提出线电极微幅往复走丝促进加工间隙内电解产物排出的方法,改善了加工稳定性,提高了加工精度和加工效率。建立了间隙内电解产物排出效率对加工精度、加工速度影响的数学模型,分析了线电极走丝速度和走丝幅值对间隙内电解产物排出和电解液更新的影响。通过试验研究了线电极的走丝速度和走丝幅值对加工精度和加工效率的影响规律,采用优化参数在厚度为80 μm的钴基弹性合金上进行微槽结构加工,底面粗糙度约为0.45 μm,倒角半径小于8 μm。结果表明线电极轴向微幅往复走丝可以有效地提高加工质量和加工效率。 相似文献
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叶盘通道电解加工(ECM)是决定整体叶盘电解加工成形精度的关键工序,其加工间隙不规则、建模困难。基于Realizable k-ε模型建立叶盘通道电解加工的气液两相流模型,根据参数传递关系建立多物理场耦合模型,分析加工间隙内电解液温度、氢气体积分数、电导率等重要参数的分布规律。仿真结果显示电解液在侧面间隙出现涡流现象,使该区域氢气堆积、温度上升,影响工件的成形表面质量,并导致该处的材料蚀除量减小,该结果在试验中得到证实。试验与仿真得出的工件轮廓形状变化趋势一致,试验与仿真获得的端面平衡间隙尺寸分别为0.26、0.33 mm,仿真的相对误差(27%)明显小于经典公式的相对误差(73%)。因此,模型可较为准确地模拟叶盘通道电解加工成形过程,反映各参数对工件成形的影响过程。 相似文献
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TB6钛合金由于具有优越的性能,广泛地用于航空航天领域。然而从大余量的TB6钛合金锻铸件毛坯加工成复杂结构的零件,其加工效率低,刀具和机床成本高,造成了极大的浪费。为解决这一问题,提出了一种利用薄型中空电极进行快速大余量去除的电解加工(ECM)方法,即将零件与多余材料切割分离,有望较大程度提高加工效率,降低加工成本。为改善电解加工流场特性,提高加工精度,对电极施加振动,并对薄型中空电极的振动切割进行了建模分析和试验研究。试验结果表明,合适的振动幅值和频率(A=0.05mm,f=50Hz)可以使得各处电解液电导率趋于一致,从而提高加工的精度、稳定性和效率。复杂结构件的成功切割证明了薄型中空电极振动电解切割加工技术具有一定的适用性。 相似文献
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整体叶盘电解加工中,流场对加工稳定性起着重要作用,电解液进液角度对流场均匀性具有重要影响。针对由叶尖至叶根流动模式,设计了5种电解液进液角度流动模型(12°、22°、32°、42°以及52°),并开展电解加工流场仿真研究。结果表明,电解液进液角度为32°时,平均流速为19.01 m/s,流速均方差为6.33,满足整体叶盘电解加工对流场的要求。在电解液进液角度为32°的流场形式下,开展整体叶盘电解加工试验,加工过程稳定,试件表面无流纹,加工精度为0.12 mm,表面粗糙度为Ra0.353μm,验证了流场的合理性。 相似文献
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照相电解加工的由来、发展和应用前景。采用高速流动的中性电解液,代替在电解液槽内浸泡或搅拌等传统方法后,照相电解加工成为高温合金薄板群孔的最佳加工方法之一。 相似文献
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为提高微细电解射流加工效率及加工质量,研制了专用喷射装置,并利用该装置进行了初步工艺试验。结果证明该装置保证了电解液在其腔体中能够得到充分"负极化",且能获得满足加工要求的稳定破碎长度,满足了电解射流加工试验要求。 相似文献
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Electrochemical drilling(ECD) provides an alternative technique for drilling multiple small holes in difficult-to-machine materials in numerous industrial applications such as for aeroengines. The value and fluctuation of electrolyte flowrate can seriously affect the machining stability and hole quality in ECD. In particular, when drilling multiple holes, the distribution and fluctuations of the electrolyte flowrate in each channel could influence the uniformity of the electrolyte flowrate among... 相似文献
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钛基复合材料是一种典型的难加工材料,采用传统机械加工方法存在加工效率低和加工质量差等问题。利用电解加工技术,采用直径为10mm的管状阴极,对(TiB+TiC)/TC4复合材料进行电解钻孔加工试验研究。进行了(TiB+TiC)/TC4复合材料的电化学特性研究,测量了(TiB+TiC)/TC4复合材料在10%NaNO3溶液中的极化曲线和电流效率。探究了加工电压、电解液压力对加工精度的影响。结果表明,当加工电压为30V,电解液压力为0.6MPa时,电解钻孔可以在1mm/min的进给速度下稳定加工。当加工的盲孔深径比为3.06时,孔的圆度误差为41.1μm,锥度为0.4°,具有较高的加工精度。 相似文献
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As two kinds of defects, recast layers and spatters, commonly accompanied by laser-drilled holes always prevent the laser drilling technique from extending its applications in aerospace and aircraft industries, therefore, a novel hybrid process incorporating laser drilling with jet electrochemical machining (JECM-LD) has been developed to solve these problems as well as improve the overall quality of laser-drilled holes. It is executed by directing an electrolyte jet coaxially aligned with a laser beam onto the workpiece surface. During the process, the electrolyte jet produces electrochemical reaction with the surface material, effective cooling of it and carries away the process scraps. A two-dimensional mathematical model is proposed to describe the shape of the holes machined by JECM-LD. The model is verified through comparison between the results from simulation and those from experiments conducted on the test pieces made of 321 stainless steel 0.5 mm thick processed by the pulsed Nd:YAG laser at second harmonic wavelength. An examination of the experimental results under an optical microscope discovers that, by contrast with the laser drilling in air, the JECM-LD has effectively removed the recast layers and spatters, but its efficiency dropped by about 30%. 相似文献
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Optimization of flow field in electrochemical trepanning of integral cascades (Ti6Al4V) 总被引:1,自引:0,他引:1
《中国航空学报》2022,35(10):354-364
Ti6Al4V is widely applied in the integral cascades of aero engines. As an effective machining method, electrochemical trepanning (ECTr) has unique advantages in processing surface parts made of hard-to-cut materials. In ECTr, the state of the flow field has a significant effect on processing stability and machining quality. To improve the uniformity of the flow field when ECTr is applied to Ti6Al4V, two different flow modes are designed, namely full-profile electrolyte supply (FPES) and edges electrolyte supply (EES). Different from the traditional forward flow mode, the flow directions of the electrolyte in the proposed modes are controlled by inlet channels. Simulations show that the flow field under EES is more uniform than that under FPES. To further enhance the uniformity of the flow field, the structure of EES is optimized by modifying the insulating sleeve. In the optimized configuration, the longitudinal distance between the center of the inlet hole and the center of the blade is 6.0 mm, the lateral distance between the centers of the inlet holes on both sides is 16.5 mm, the length to which the electrolyte enters the machining area is 1.5 mm, and the height of the insulating sleeve is 13.5 mm. A series of ECTr experiments are performed under the two flow modes. Compared with EES, the blade machined by FPES is less accurate and has poorer surface quality, with a surface roughness (Ra) of 3.346 μm. Under the optimized EES, the machining quality is effectively enhanced, with the surface quality improved from Ra = 2.621 μm to Ra = 1.815 μm, thus confirming the efficacy of the proposed methods. 相似文献
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In aero-engines, mortise-tenon joint structures are often used to connect the blades to the turbine disk. The disadvantages associated with conventional manufacturing techniques mean that a low-cost, high-efficiency, and high-quality nickel-based mortise–tenon joint structure is an urgent requirement in the field of aviation engineering. Electrochemical cutting is a potential machining method for manufacturing these parts, as there is no tool degradation in the cutting process and high-quality s... 相似文献
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Flow field design and process stability in electrochemical machining of diamond holes 总被引:2,自引:1,他引:1
《中国航空学报》2016,(6):1830-1839
The metal grille, commonly composed of an amount of diamond holes, has been grow-ingly used as a key structure on stealth aircraft. Electrochemical machining (ECM) promises to be increasingly applied in aircraft manufacturing on the condition that process stability is guaranteed. In this work, a flow field model was designed to improve the process stability. This model is endowed with a variety of flow channel features, together with vibrating feeding modes. The flow field distribution on the bottom surface of the diamond hole was discussed and evaluated as well. The numerical results show that a short arc flow channel could significantly enhance the uniformity of electrolyte velocity distribution and a vibrating feeding of the cathode enables to reduce both fluctuations of the electrolyte velocity and pressure on the bottom surface of the diamond hole. Consequently, the flow field mutations were eliminated. It is verified from the experimental results that a short arc flow channel, when combined with vibrating feeding, is capable of improving machining localization and process stability markedly. What is more, the side gap on the bottom surface of the diamond hole could also be reduced by the abovementioned approach. 相似文献
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