Papers by Keyword: Electric Discharge Machining (EDM)

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Authors: Bai Dong Jin, Guo Hui Cao, Zhen Long Wang, Wan Sheng Zhao
Abstract: A new micro EDM method is described. First, the basic principles of micro EDD are analyzed and realized conditions are predicted. Then with an ordinary EDM shaping machine and electrode brass, steel and tungsten, a large number of experiments are carried out in air to obtain the effects of different processing parameters on micro EDD. A micro cylinder with 0.19mm in diameter and 7.35mm in height is formed on high-speed steel surface. By exchanging the polarities of electrode and workpiece the deposited material can be removed selectively, thus the reversible machining is realized. In the end, measurements show that the deposited material is compact and hardened, whose components depend on the tool electrode material although Zn in brass electrode is oxidized to ZnO.
32
Authors: Jiang Wen Liu, T.M. Yue, Zhong Ning Guo, Z. Y. Wan, G.Y. Liu
Abstract: A new concavo-convex electrode has been designed and fabricated. And an analysis of the electrical discharge machining (EDM) of a particulate reinforced metal matrix composite this new electrode was conducted in this study. The material removal rate (MRR) of new electrode and normal electrode are compared in different applied voltage and duty cycle conditions. It was found that EDM with this new electrode can accelerate the debris discharge during machining so that it has a higher MRR compared to the case where a normal electrode was employed. Moreover, by studying the waveforms, it could confirm that a stable processing condition can be obtained by employing the new electrode. The experiment results reveal that it is a feasible and effective way to machine MMCs by employing this new electrode.
294
Authors: Jiang Wen Liu, T.M. Yue, Zhong Ning Guo, Z. Y. Wan, G.Y. Liu
Abstract: A new concavo-convex electrode has been designed and employed. And an analysis of the electrical discharge machining (EDM) mechanism of a particulate reinforced metal matrix composite with this new electrode was conducted in this study. It was found that EDM with this new electrode can accelerate the debris discharge during machining so that it has a higher MRR compared to the case where a normal electrode was employed. Moreover, by studying the surface craters, it could confirm that discharge craters tend to connect together for the normal electrode. This indicates an abnormal arcing condition. Thus, the wire electrode was easy to be broken. While for the new electrode, separated craters were observed on the machined surface. This means a stable processing condition. The experiment results reveal the processing mechanism of EDM electrical discharge machining of MMCs by employing this new electrode.
300
Authors: Zhen Long Wang, Yu Fang, Wan Sheng Zhao, K. Cheng
592
Authors: Li Zhang, Li Hua Dong, D.S. Wang, C.H. Fan, Y. Zhou
Abstract: This work screens electrode materials used in EDM and proposes some potential electrodes for future industrial applications. Traditional graphite, W, and Mo EDM electrodes have low TWR due to their high melting points; while, Zn, brass, and Cu often experience too much tool wear. As to some newly developed alloy and composite materials, their machining performances depend on not only their melting points but also their microstructures. Cu-W alloy has high wear resistance but it is susceptible to shape loss due to its internal porosity. By contrast, Cu-graphite, Cu-ZrB2 and Cu-TiB2 composites show good capabilities of removing material with little wear loss and therefore could be promising for future usages.
495
Authors: Jiang Wen Liu, Guang Xue Chen, Tai Man Yue, Zhong Ning Guo, Zi Yao Wan
Abstract: A new concavo-convex electrode has been designed and employed and it was reported that electrical discharge machining (EDM) of particulate reinforced metal matrix composites with this kind of new electrode can accelerate the debris discharge during machining so that it has a higher material removal rate (MRR) compared to the case where a normal electrode was employed. Since there are many factors that can affect the MRR in the EDM process with the concavo-convex electrode, in order to determine which is the most important factor and to optimize the machining parameters, the relative importance of the various cutting parameters on material removal rate was established using an orthogonal experimental analysis in this study. The results of the analysis suggest that to achieve a high MRR for particulate reinforced aluminum 6061 with 10-vol% Al2O3 (10ALO) or 20vol% Al2O3 (20ALO) using a concavo-convex electrode, the duty cycle is the most influential factor among current, pulse duration and duty cycle.
890
Authors: Kiyoshi Suzuki, Shinichi Ninomiya, Manabu Iwai, Y. Tanaka, Yoshihiko Murakami, Sadao Sano, Katsutoshi Tanaka, Tetsutaro Uematsu
Abstract: Electro-discharge grinding (hereafter called ED-grinding) was carried out with a trial manufactured metal bond diamond wheel containing electrically conductive diamond grits (hereafter called EC-D-grits-wheel). In this research two effects i.e. removal action of workpiece by electrical discharge machining, and an in-process dressing action of the cutting edges on the grits are expected to take place. The results of ED-grinding with EC-D-grits-wheel (f100mm, SDE120Q80M) on tungsten carbide indicated a significant decrease of 21% in the grinding force, when the set discharge current was increased from 0A to 12A. It was also clarified from the alternative-grinding test with and without an electro-discharge action that stable grinding characteristics along with a reduced grinding force could be achieved in the case of the EC-D-grits-wheel with the electro-discharge action. High-speed camera photographs indicated that a stable discharge condition was achieved.
63
Authors: Yukari Ishikawa, Yong Zhao Yao, Koji Sato, Yoshihiro Sugawara, Yoshihiro Okamoto, Noritaka Hayashi
Abstract: The damage induced at the cut surface of SiC crystal by slicing were investigated by Raman scattering method and transmission electron microscopy. Electric discharge machining (EDM) predominately forms cracks, silicon, carbon and 3C-SiC by 6H-SiC pyrolysis and wiresawing with loose abrasive (WSLA) induces triangular crystal disordered area, stacking faults and dislocation loop bundles by stressing at the cut surfaces of SiC crystal.
362
Authors: Tomohisa Kato, Toshiya Noro, Hideaki Takahashi, Satarou Yamaguchi, Kazuo Arai
Abstract: In this study, we report electric discharge machining (EDM) as a new cutting method for silicon carbide (SiC) single crystals. Moreover, we discuss characteristics and usefulness of the EDM for the SiC. The EDM realized not only high speed and smooth cutting but also lower surface damage. Defect propagation in the EDM SiCs have been also estimated by etch pits observation using molten KOH, however, we confirmed the EDM has caused no damage inside the SiCs in spite of high voltage and high temperature during the machining.
855
Authors: Mohammad Reza Shabgard, Babak Sadizadeh, Keivan Amini, Hamid Pourziaie
Abstract: The correct selection of the machining parameters is one of the most significant issues to take into consideration in Ultrasonic-assisted Electrical Discharge Machining (US-EDM) and EDM processes. In the present work, a study has been made to develop and extract statistical models to show the relationship between important machining performance data (material removal rate (MRR), tool wear ratio (TWR) and surface roughness Ra) and the input machining parameters (pulse current, and pulse-on time) in the EDM and US-EDM of AISI H13. The models obtained were used to analyze the effects of input parameters on machining performance. In addition, a comparative study was carried out to investigate the effect of ultrasonic vibration of the workpiece on machining performance. The results show that Ultrasonic vibration of the workpiece can significantly reduce the inactive pulses and improves the stability of process. Also US-EDM is effective in attaining a high material removal rate (MRR) in finishing regime in comparison with conventional EDM. The results of Analysis of Variance (ANOVA) indicate that the proposed mathematical models can adequately explain the performance within the limits of the factors being studied.
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