The selection of EDM (electrical discharge machining) graphite electrodes for mold manufacturing should focus on processing accuracy, processing efficiency, electrode wear, and surface finish. The core is to match the complexity of the mold, precision requirements, and processing conditions, avoiding electrode selection errors and low efficiency due to improper electrode selection. First, select the graphite grain size based on the precision and complexity of the mold. For high-precision and complex structure molds (such as precision injection molds, die-casting molds), choose fine-grained graphite (particle size ≤ 5μm), which has a high surface finish and good edge precision, enabling thin-wall processing of 0.1mm or less, meeting the requirements of precision molds; for ordinary precision and simple structure molds, choose medium-fine-grained graphite to reduce electrode cost and improve processing efficiency. Secondly, pay attention to the density and hardness of the graphite. High-density graphite (≥ 1.8g/cm³) has a dense structure and low electrode wear, good processing stability, suitable for long-term and high-precision processing; low-density electrode wear is faster, suitable for short-term, ordinary precision processing. At the same time, consider the conductivity of the graphite. The lower the resistivity, the higher the efficiency of electrical discharge machining, and the lower the electrode wear rate, preferentially choose graphite materials with low resistivity. In addition, during mold processing, heat is generated, so choose graphite electrodes with excellent thermal shock resistance to avoid electrode deformation due to temperature changes, affecting processing accuracy. Finally, when purchasing, confirm the uniformity of the graphite electrode to avoid internal pores or impurities causing abnormal discharge during processing. Based on the parameters of the processing equipment (such as current, voltage), select the appropriate graphite electrodes, and adjust the electrode selection in combination with the material of the mold (such as steel, alloy). Conduct small-scale tests before processing to optimize the processing parameters, ensuring that the electrodes match the processing conditions and improving the accuracy and efficiency of mold processing.
English
