共查询到20条相似文献,搜索用时 265 毫秒
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根据锥形水射流钻头螺旋曲面叶轮的几何展成原理,研究了用数控电火花成形机对其展成加工一次成形的方法,讨论了展成加工中存在的电极干涉而导致的过切现象以及成形电极的修正设计方法。 相似文献
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分析了电火花成形加工中的一些不稳定因素对电极损耗和使用寿命的影响,针对性地提出了合理有效地利用极性效应、面积效应、吸附效应以及对电参数和电极材料的合理选取等措施,为电火花高效低损耗加工、延长电极使用寿命提供了保障. 相似文献
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提出了一种可用于难加工材料大余量高速蚀除的新的放电加工方法——基于流体动力断弧的高速电弧放电加工。与传统的电火花加工方法相比,高速电弧放电加工采用具有更高能量密度的电弧放电而不是火花放电来实现材料的蚀除;与其他利用电弧进行材料去除的工艺方法相比,高速电弧放电加工可使用特殊设计的成形电极实现强制多孔内充液,从而获得三维复杂型腔的沉入式加工能力,因此具有更广泛的应用前景。初步实验表明,对于镍基高温合金等难切削材料,高速电弧放电加工的材料去除率(MRR)远高于传统的电火花加工,甚至高于铣削加工。例如:加工镍基高温合金(GH4169)的材料去除率可达11 300 mm3/min,而电极损耗率(TWR)低于3%。由此可见,高速电弧放电加工在难切削材料的高效去除加工方面具有明显的技术优势。 相似文献
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Ultraprecision micromachining of hard material with tool wear suppression by using diamond tool with special chamfer 总被引:1,自引:0,他引:1
This study aims to develop an ultraprecision machining method which enables to suppress tool wear in the machining of hard material by using the tool with special chamfer. As a result, the cutting point swivel machining is proposed, and its effect is experimented in the machining of SiC. Then, the relationship between the speed ratio and tool wear is investigated. By applying the proposed machining method to curved microgrooving and curved surface machining on Tungsten Carbide, it is confirmed that cutting point swivel machining enables to realize ultraprecision machining of complex shape. 相似文献
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《International Journal of Machine Tool Design and Research》1984,24(1):31-43
In the present work, machining characteristics of distilled water, tap water and a mixture of 25% tap and 75% distilled water when used as dielectric fluid in EDM are reported. Two different tool materials, viz., brass and copper with positive and negative polarities have been used to machine low carbon steel workpieces at low current densities. All the experiments have been planned statistically and response surface equations for metal removal rate, relative electrode wear and surface roughness have been obtained. The best machining rates have been achieved with the tap water and a special feature of machining in water was the possibility of achieving zero electrode wear specially when copper tools with negative polarities were used. 相似文献
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Ki Young Song Do Kwan Chung Min Soo Park Chong Nam Chu 《Journal of Materials Processing Technology》2013,213(9):1495-1500
Turning by electrical discharge machining (EDM turning) is an effective method to machine hard-to-cut materials. Generally, a wire-EDM is utilized in EDM turning because it is not concerned with electrode wear. However, wire-EDM turning has a slow machining speed due to its small machining area, and the wire may break due to overheating electrodes. For these reasons, its machining speed must be limited. In this study, a strip-EDM was created in an effort to overcome the problems in the EDM-turning process. This machining method used a conductive strip as an electrode. The strip was fed continuously, like a wire-EDM; therefore electrode wear was not a concern. One advantage of the strip-EDM was that it increased the material removal rate because of its large machining area and non-breaking electrode. In the experiments, machining characteristics were investigated according to machining conditions, and practical machining was carried out via fabrication of complex shapes on a shaft workpiece. 相似文献
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An extension to the electrical discharge machining method by introduction of radio-frequency plasma is proposed. Sparking with the radio-frequency plasma can be generated in paraffin oil by simple electrical circuitry. In this paper, experimental investigations are described on the fundamental effects of the resonant frequency, type of electrode and workpiece materials on machining characteristics for high performance radio-frequency machining in paraffin oil. The results show that the removal rate and the electrode wear vary with the resonant frequency and type of electrode materials. The surface roughness can be reduced to less than 1μm Rz under suitable experimental conditions. 相似文献
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Cheng-Kuang Yang Chih-Ping Cheng Chao-Chuang Mai A. Cheng Wang Jung-Chou Hung Biing-Hwa Yan 《International Journal of Machine Tools and Manufacture》2010,50(12):1088-1096
Electrochemical discharge machining (ECDM) is an emerging non-traditional machining process that involves high-temperature melting assisted by accelerated chemical etching. In this study, the tool electrode (200 μm in diameter) is fabricated by wire electrical discharge grinding (WEDG). After the tool electrode is machined, the surface roughness of tool electrode materials (stainless steel, tungsten carbide, and tungsten) is different because of the physical properties. However, the surface roughness affects the wettability on tool electrode, and also changed the coalesce status of gas film in ECDM. Hence, this study explores the wettability and machining characteristics of different tool electrode materials and their impact on gas film formation. Their machining performance and extent of wear under gravity-feed micro-hole drilling are also examined. Experimental results show that the optimal voltage of different tool electrode can shed light on the machining performance. Moreover, wettability of tool electrode is determined by surface roughness of tool material, which in turn affects the coalesce status of gas film, machining stability and micro-hole diameter achieved. In addition, differences in tool material also results in variations in machining speed. Significant tool wear is observed after repeated gravity-feed machining of 50 micro-holes. 相似文献
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Apiwat Muttamara Yasushi Fukuzawa Naotake Mohri Takayuki Tani 《Journal of Materials Processing Technology》2003,140(1-3):243-247
Electrical discharge machining (EDM) is used as a precision machining method for the electrically conductive hard materials with a soft electrode material. But recently we succeeded to machine on insulating material by EDM. The technology is named as an assisting electrode method. The EDMed surface is covered with the electrical conductive layer during discharge. The layer holds the electrical conductivity during discharge. For micro-EDM, the wear of tool electrode becomes lager ratio than the normal machining. So the micro-machining is extremely difficult to get the precision sample.
In this paper to obtain a fine and precise ceramics sample, some trials were carried out considering the EDM conditions, tool electrodes material and assisting electrode materials. Insulating Si3N4 ceramics were used for workpiece. The machining properties were estimated by the removal rate and tool wear ratio. To confirm the change of micro-machining process, the discharge waveforms were observed. The micro-machining of the Ø0.05 mm hole could be machined with the commercial sinking electrical discharge machine. 相似文献
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Fred L. Amorim Leandro J. Stedile Ricardo D. Torres Paulo C. Soares Carlos A. Henning Laurindo 《Journal of Materials Engineering and Performance》2014,23(4):1480-1488
Titanium and its alloys have high chemical reactivity with most of the cutting tools. This makes it difficult to work with these alloys using conventional machining processes. Electrical discharge machining (EDM) emerges as an alternative technique to machining these materials. In this work, it is investigated the performance of three special grades of graphite as electrodes when ED-Machining Ti6Al4V samples under three different regimes. The main influences of electrical parameters are discussed for the samples material removal rate, volumetric relative wear and surface roughness. The samples surfaces were evaluated using SEM images, microhardness measurements, and x-ray diffraction. It was found that the best results for samples material removal rate, surface roughness, and volumetric relative wear were obtained for the graphite electrode with 10-μm particle size and negative polarity. For all samples machined by EDM and characterized by x-ray (XRD), it was identified the presence of titanium carbides. For the finish EDM regimes, the recast layer presents an increased amount of titanium carbides compared to semi-finish and rough regimes. 相似文献