Influence of electrode feed directions on EDM machining efficiency of deep narrow slots
| Autor: | Xue-Cheng Xi, Wansheng Zhao, Mo Chen, Yaou Zhang, Rui-Xue Zhang, Zi-Lun Li |
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| Rok vydání: | 2021 |
| Předmět: |
Spectrum analyzer
Materials science Turbine blade Mechanical Engineering Process (computing) Mechanical engineering Industrial and Manufacturing Engineering Computer Science Applications law.invention Electrical discharge machining Machining Control and Systems Engineering law Electrode Deposition (phase transition) Turning point Software |
| Zdroj: | The International Journal of Advanced Manufacturing Technology. 117:3415-3429 |
| ISSN: | 1433-3015 0268-3768 |
| DOI: | 10.1007/s00170-021-07907-5 |
| Popis: | Deep narrow slot (DNS) structures are commonly used in slots for inserts in tire molds, die-casting molds of heat-dissipating fins, grooves in flexible joints of gyros, and seal slots in turbine blades. Electrical discharge machining (EDM) of DNSs is a time-consuming process, because traditional EDM machines adopt a vertical downward feed direction to remove materials, resulting in debris deposition in the gap by means of gravity. In this paper, systematic experiments are carried out to investigate the effect of different feed directions on the machining efficiency of EDM DNS structures. Thirteen feed directions with an incremental angle of 15° from −90 to 90° have been tested without electrode jumps. Among them, the feed directions of 0° and 15° have the highest machining efficiency, which even exceeds the machining efficiency achieved with electrode jumps. A machining efficiency model with respect to feed direction is built based on experimental results. The gap discharge state is acquired by an FPGA circuit based on discharge state analyzer, associated with machining efficiency curves. For most feed directions, the discharge rate drops significantly after the machining depth around 4 mm, leading to an obvious turning point in the machining efficiency curve. To explore the reasons for machining efficiency changes during the machining of DNS, the movements of bubbles are observed by a high-speed camera for calculating their speeds and sizes. |
| Databáze: | OpenAIRE |
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