Study Of Machanism And Stability Mist-jetting Electric Discharge Milling

Mist-jetting electric discharge milling is a new promising machining method that corresponds to the green-machining trend. However, when using mist generated from tap water, the droplets are uneven and the short circuit rate is high, which cause an unstable machining process. By using ultrasonic atomizer to generate even micro fog drops from de-ionized water, the short circuit rate reduced greatly and the stability of EDM machining enhanced obviously.Before the experiments of mist-jetting ED-milling, flow rate and flow type in the electrode is studied. And FEM method is used to compute air distribution and drop track in electrode, by using FLUENT software. It can be confirmed that discharging is happened in the mist, instead of water. And assistant vibration of the workpiece can not only reduce short circuit rate but also enhance material removal rate and tool wear rate.To improve the stability of mist-jetting ED-milling, mist is jetted from exterior tube. Experiments results show that, the debris are expelled sufficiently, and short circuit rate is reduced. When discharging energy is lower, tool wear rate is raised rapidly, so work piece is covered by copper. Contrast experiment shows that, white layer of work piece processed by mist-jetting ED-Milling was one third of traditional EDM's, and there is scarcely any crack. At last, assistant ultrasonic vibrator also used to enhance surface quality of work piece.