Additive Manufacturing of Gear Electrodes and EDM of a Gear Cavity

Plastic gears are used in a variety of industrial fields and are primarily produced by injection molding with a gear cavity. At present, EDM is usually used for machining gear cavities with metal materials, and the tool electrode used in the process is usually machined through a milling process. For helical gear cavities and helical bevel gear cavities, certain problems are encountered when the tool electrodes of EDM are obtained from milling procedures, including waste of raw materials and the complex technical process. Focusing on the above problems, this paper used copper powder to fabricate gear electrodes through a selective laser sintering process. The obtained gear electrodes underwent heat treatment and the effects of the main process parameters on the electrical conductance of tool electrodes were analyzed in this study. Finally, the heat-treated gear electrodes were applied to EDM to fabricate a helical gear cavity and a helical bevel gear cavity. During EDM, the TWR and MRR of the gear electrodes were 0.0029 mm³/min and 0.3872 mm³/min, respectively. Compared with that of gear electrodes made by the milling process, the MRR of the gear electrodes fabricated by SLS improved by 31.53%.