An electrode applied in electro-machining processes, where the electrode includes a main body portion and at least one built-in internal flushing passage for introducing a flushing liquid to a volume between the electrode and a workpiece to be machined. The electrode is made by an additive fabrication process that enables specialized flushing for enhancing waste material evacuation and incorporate special material properties like zones of high electrical conductivity and thermal resistance. The fabrication process produces materials and geometries that could not otherwise be made using conventional processing.

A method for electrical discharge machining a work piece using rectangular processing pulses includes forming the rectangular processing pulses by discharging one or multiple discrete delay lines that comprise multiple storage elements. The storage elements are arranged as part of a feed line to a spark gap on a section of the feed line near the spark gap. The discrete delay lines are connected to a guide head by an electrode-side contact unit and are connected to the work piece by a work piece-side contact unit.

A method for electrical discharge machining a work piece using rectangular processing pulses includes forming the rectangular processing pulses by discharging one or multiple discrete delay lines that comprise multiple storage elements. The storage elements are arranged as part of a feed line to a spark gap on a section of the feed line near the spark gap. The discrete delay lines are connected to a guide head by an electrode-side contact unit and are connected to the work piece by a work piece-side contact unit.

An electrical discharge machining electrode wire includes a core including a copper or a copper alloy, and a covering layer that covers a periphery of the core and includes a zinc. The covering layer includes an outermost layer consisting of an -phase of a copper-zinc based alloy. The outermost layer has a Cu concentration of 12 to 20 mass % and a variation range within 5 mass % in the Cu concentration in a longitudinal direction of the electrode wire.

An electrical discharge machining electrode wire includes a core including a copper or a copper alloy, and a covering layer that covers a periphery of the core and includes a zinc. The covering layer includes an outermost layer consisting of an -phase of a copper-zinc based alloy. The outermost layer has a Cu concentration of 12 to 20 mass % and a variation range within 5 mass % in the Cu concentration in a longitudinal direction of the electrode wire.

A controller for controlling a wire electric discharge machine is configured to monitor the remaining lifetime of a wire electrode and calculates an electric discharge machining time, thereby determining the timing of replacement of the wire electrode, so that it can recognize the timing of interruption of electric discharge machining. Consequently, a program operation can be suspended and the wire electrode can be cut and automatically replaced at that timing. After the replacement of the wire electrode, moreover, the wire electrode can be connected and the program operation can be restarted.

An object is to provide a graphite-copper composite electrode material that is capable of reducing electrode wear to a practically usable level and to provide an electrical discharge machining electrode using the material. A graphite-copper composite electrode material includes a substrate comprising a graphite material and having pores, and copper impregnated in the pores of the substrate, the electrode material having an electrical resistivity of 2.5 m or less, preferably 1.5 m or less, more preferably 1.0 m or less. It is desirable that the substrate comprising the graphite material have an anisotropy ratio of 1.2 or less. It is desirable that an impregnation rate of the copper in the electrode material is 13% or greater. It is desirable that the substrate comprising the graphite material have a bulk density of from 1.40 Mg/m.sup.3 to 1.85 Mg/m.sup.3.

An object is to provide a graphite-copper composite electrode material that is capable of reducing electrode wear to a practically usable level and to provide an electrical discharge machining electrode using the material. A graphite-copper composite electrode material includes a substrate comprising a graphite material and having pores, and copper impregnated in the pores of the substrate, the electrode material having an electrical resistivity of 2.5 m or less, preferably 1.5 m or less, more preferably 1.0 m or less. It is desirable that the substrate comprising the graphite material have an anisotropy ratio of 1.2 or less. It is desirable that an impregnation rate of the copper in the electrode material is 13% or greater. It is desirable that the substrate comprising the graphite material have a bulk density of from 1.40 Mg/m.sup.3 to 1.85 Mg/m.sup.3.

A wire electrical discharge machine includes: a supporting member for relatively moving a wire electrode relative to a measurement target; servomotors for moving the supporting member; a setting changer for changing the setting of a directive speed; and a motor controller that controls the servomotors in performing move-and-contact detection for detecting contact between the wire electrode and the measurement target by moving the two relative to each other, so that the wire electrode is moved relative to the measurement target based on the directive speed changed and specified by the setting changer.

A wire electrical discharge machine includes: a supporting member for relatively moving a wire electrode relative to a measurement target; servomotors for moving the supporting member; a setting changer for changing the setting of a directive speed; and a motor controller that controls the servomotors in performing move-and-contact detection for detecting contact between the wire electrode and the measurement target by moving the two relative to each other, so that the wire electrode is moved relative to the measurement target based on the directive speed changed and specified by the setting changer.