Abstract: A new reversible electric discharge machining (EDM) technology is discussed. This method can selective deposite and remove metal materials on workpiece surface by pulse discharge between positive and cathode in gas using ordinary EDM machine tool. The precondition to realize reversible EDM is demonstrated and doped out according to the EDM basic theory. Experiments show that metal electrode materials, such as steel, copper and tungsten, can be deposited on steel workpiece surface and to form micro cylinder which diameter are 100~240 mm and height are 1 000~2 500 mm. Then some EDM removal experiments are carried out to the deposited cylinder by reverse the machining polarity and proper contrail controlling. So the reversible EDM technology is confirmed. Experiments also show that the materials formed by electric discharge deposition is compact and hardness, and combine workpiece surface tightly. Therefore the deposition materials can meet for engineering demand.

Key words: Discharge deposition, EDM, Reversible machining