Processing forms and procedures for graphite electrodes

Processing forms and procedures for graphite electrodes
Processing forms of graphite materials
There are three main forms of processing graphite electrodes: pressure vibration method, CNC automatic forming method, and mechanical processing method.
(1) Numerical Control Automatic Forming Method: The numerical control automatic forming method requires a dedicated graphite electrode forming machine, which adopts numerical control mode and has a tool automatic exchange device that can accommodate multiple tools. To improve the processing environment, a water curtain is used to surround the graphite electrode to prevent the dispersion of graphite dust. In addition, wet machining can also be used, using water-soluble cutting fluid to prevent tool wear and graphite dust from scattering. The machine tool has a high-performance filtering device that can separate cutting fluid and graphite chips, ensuring long-term continuous processing. It is an ideal specialized equipment for graphite electrode machining.
(2) Pressure vibration method: The pressure vibration method requires a specialized machine tool, and the electrode master mold is opposite in shape to the electrode. Graphite materials and forming tools are placed relative to each other during processing, leaving a certain gap. Inject machining fluid made of a mixture of water and abrasive into it. Simultaneously, ultrasonic vibration is applied to graphite and forming tools through the processing fluid. Under the action of abrasive impact force, graphite is stripped away in trace amounts to form the desired shape. The abrasive is SiC, B4C or diamond, and the coarser the abrasive, the faster the processing speed. The machine tool uses sealed and water curtain methods for processing during operation. Electrical discharge machining suitable for mass production situations.
(3) Mechanical processing method: Mechanical processing method is the main method adopted by general mold production units in China.
Graphite materials can be processed using methods such as turning, milling, drilling, and grinding. In addition, graphite materials are prone to generating dust particles during mechanical processing, which can have adverse effects on processing equipment and operators.
Processing procedures for graphite materials
(1) Graphite immersed in oil. Before mechanical processing, graphite materials should be immersed in engine oil for dozens of hours to allow the oil to penetrate the graphite material, so that the dust powder will not fly during mechanical processing and a smoother surface can be obtained.
(2) Paint and draw lines. After rough machining on the outer surface of the electrode, a thin layer of white paint is sprayed on the marking surface before marking, so that the lines are clear and easy to machine.
(3) Perform mechanical processing.