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*STUDY ON HIGH-QUALITY FINISHING BY EDM WITH NONFLAMMABLE DIELECTRIC FLUID
The use of kerosene as dielectric fluid in EDM is very common. However, from the point of safety, kerosene has many problems since it can cause a fire. Some studies were reported on EDM with conflammable dielectic fluid. EDM with nonflammable dielectric fluid has an advantage over EDM with kerosene because it is free from fire and its rough-machining speed is faster. On the other hand, it has a drawback in that its finishing machining is unsatisfactory. In this report, the authors aim is to improve the efficiency of EDM with nonflammable dielectric fluid. The authors have found that the carbon which is made in the EDM process is responsible for the poor quality of the finished surface. Because it is electrified, the carbon adheres to the surface of the workpiece in the EDM process. The adhering carbon disturbs the machining stability, and degenerates the quality of the EDMed surface. In order to improve the machining capacity, the authors developed a new machining circuit. With this machining circuit, the voltage between the electrode and the workpiece is kept about 0 V, and the electrified carbon does not adhere to the workpiece. The performance of finishmachining is greatly improved.
*INCREASING THE FUNCTIONALITY OF MACHINED SURFACES BY EDM WITH A SILICON POWDER ADDITIVE
In EDM a very smooth finished surface can be obtained by adding a fine electrically conductive powder such as silicon to the machining fluid. Since this process produces an extermely corrosion resistant and microcrack free uniform surface, it is thought to be very effective in the finishing of dies for plastic molding. Increased effectiveness against corrosion is particularly needed for molds in which corrosive gases develop from plastic compounds.
In this paper, in order to investigate the effective application of EDMing using a powder additive in the plastic mold finishing process, surfaces by Powder Additive EDM were compared to those finished by conventional polishing.
*EQUIVALENT MODEL OF JUMP FLUSHING EDM (Ist Report) Proposal of a Model Represented by Electric Circuit
In diesinking EDM, the jump flushing is generally known to be useful to clean up the working gap. However, it is very difficult to adjust the jump parameters efficiently such as an amplitude and an execution timing of the jump motion with progress of machining. Because, in this process, optimal values of such parameters change widely with progress of machining and to adjust
Jain Educationa International
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