tailieunhanh - Comparison of energy and removal efficiencies between micro and macro EDM Mohd Zahiruddin, Masanori Kunieda
(BQ) Micro and macro EDM are similar, but differences in machining conditions result in a differing power density, Pe. This causes differences in the ratio of energy consumed for material removal with regard to energy distributed into the workpiece, and the ratio of total removal volume per pulse with respect to the molten area volume, so-called energy efficiency, Ee, and removal efficiency, Re, respectively. It was found that, the Pe of micro EDM is approximately 30 times greater than that of macro EDM. Consequently, Ee and Re in micro EDM were significantly greater than those of macro EDM. | CIRP Annals - Manufacturing Technology 61 (2012) 187–190 Contents lists available at SciVerse ScienceDirect CIRP Annals - Manufacturing Technology jou rnal homep age : ht t p: // ees .e lse vi er . com /ci r p/ def a ult . asp Comparison of energy and removal efficiencies between micro and macro EDM Mohd Zahiruddin, Masanori Kunieda (1)* Department of Precision Engineering, School of Engineering, The University of Tokyo, 113-8656 Tokyo, Bunkyoku, Hongo 7-3-1 Building 14, Japan A R T I C L E I N F O A B S T R A C T Keywords: EDM Micromachining Power density Micro and macro EDM are similar, but differences in machining conditions result in a differing power density, Pe. This causes differences in the ratio of energy consumed for material removal with regard to energy distributed into the workpiece, and the ratio of total removal volume per pulse with respect to the molten area volume, so-called energy efficiency, Ee, and removal efficiency, Re, respectively. It was found that, the Pe of micro EDM is approximately 30 times greater than that of macro EDM. Consequently, Ee and Re in micro EDM were significantly greater than those of macro EDM. ß 2012 CIRP. 1. Introduction Electrical discharge machining, EDM is capable of producing intricate shapes on any electrically conductive material regardless of hardness, but the efficiency is low compared to conventional methods. Therefore, a thorough understanding of EDM efficiency is required for further improvement to be made. In this work, energy efficiency, Ee and removal efficiency, Re will be studied, which refer to the ratio of energy consumed for material removal with regard to the energy distributed into the workpiece, and the ratio of total removal volume per pulse with regard to the molten area volume, respectively. In EDM, even under identical energy conditions, differing performances can be observed between discharges with higher peak currents at shorter discharge durations and those of lower peak currents at longer
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