Improvement of curved hole EDM drilling performance using suspended ball electrode by workpiece vibration

Small-diameter curved hole EDM drilling method using a metal ball electrode suspended with flexible thin foil has been studied using zinc alloy with low melting point as workpiece material. In order to improve the drilling performance and to extend drillable hole depth for practical materials, such as aluminium alloy and steel, curved hole drilling with workpiece vibration was proposed in this study. The influences of discharge conditions and vibration amplitude on the machining characteristics were experimentally investigated. Various types of curved holes were successfully drilled in practical materials by EDM using the suspended ball electrode with workpiece vibration.