| High-speed Wire-cut EDM has been widely used in the field of machining with good performance and low cost. A lot of research work has been done on the structure, pulse power supply, control system and cutting process of High-speed Wire-cut EDM. But the study of the mechanism is not deep enough. The problem of how to judge the service life of the working liquid is not clear. This paper introduced the systematic research of the above problems, the main research contents are as follows:1) The discharge circuit model of metal materials was established. The reason for the passivation film formation of High-speed Wire-cut EDM was studied. The passivation film was formed by the electrochemical reaction of the leakage current under the condition of certain electrical conductivity fluid.2) The relationship between the energy of the leakage current and the discharge gap were analyzed. The energy is mainly influenced by the probability and the pulse width of the leakage current. The test results showed that High-speed Wire-cut EDM is gap discharge before dense passivation film forming.3) The passivation film was influenced by the fluid conductivity, feed rate, pulse width and duty ratio, which influenced the trimming of multi-cutting. The compensation of multi-cutting was increased by the reduction of the fluid conductivity or the raising of the feed rate and duty ratio. But the compensation would reduce when the feed rate and duty ratio was more than a certain value.4) The relationship between the pulse probability and surface quality, fluid conductivity, machining efficiency was studied. The pulse probability could effectively indicate the discharge status and the service life of the working liquid, which is a new indication of the detection of the service life of the fluid.5) The detection device of pulse discharge probability was designed, which achieved the real-time detection of the service life of the working liquid... |
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