Graphite electrode for spark erosion machining - where cast pattern made from plastic contg corundum is used to shape electrode

摘要

Process for mfg. a graphite electrode for the spart-erosion machining of hollow profiles in tools by (a) making a positive pattern of the cavity; (b) clamping the pattern to a plate and moving it in a planetary and vertical manner to obtain an enlarged, negative, intermediate pattern; (c) casting an enlarged intermediate positive from the enlarged negative; (d) using (c) to produce a friction tool cast in a hardenable plastic contg. grinding corundum; (e) tool (d) is used to shape the electrode from a graphite block using a vertical and planetary motion. The novelty is that pattern (a) is mad made from a hardenable mixt. of plastic and grinding corundum, which is cast and used to form negative (b). A simple method of making an accurate graphite electrode saving time and skilled labour.