Abstract: The invention relates to a work station for electrochemically machining a workpiece, having a number of recesses, including a base structure; a module which is fastened to the base structure and is configured to electrochemically machine the workpiece. A workpiece holder is fastened to the base structure. The workpiece holder is movable relative to the base structure along a feed axis which is parallel to the axis of rotation of the module. The module includes an electrode carrier arrangement, which is coupled to the module base body so the electrode carrier arrangement can be rotated together with the module base body about the axis of rotation of the module. The electrode carrier arrangement has a carrier frame and an electrode frame, where at least one electrode is detachably fastened to the electrode frame.

Abstract: An Electro Chemical Grinding (ECG) quill includes a tool manufactured of a porous tool material having a multitude of pores. An ECG electrolyte is communicated through a hollow tool shank for communication through the porous tool material to manufacture a slot.

Abstract: A method of producing a component includes the steps of: providing a workpiece generated by hot isostatic pressing a powder metal form; and electropolishing a surface of the workpiece to remove a substantially uniform surface layer of the workpiece to produce the component. Following the electropolishing step, the component has substantially the same shape as the workpiece produced by the hot isostatic pressing step.

Abstract: A method for manufacturing gear wheels, specifically transmission gear wheels, is disclosed. An embodiment of the method includes the following steps: a) preparation of a base body for a gear wheel, b) electrochemical processing of the base body by a precise electrochemical machining process (PECM process), where several recesses running between the teeth of the gear wheel are made simultaneously electrochemically to manufacture the teeth of the gear wheel.

Abstract: Disclosed is an electrode arrangement for the defined rounding or deburring of edges of electrically conductive components, in particular turbine components, by means of electrochemical machining with at least one working electrode (5), which has a tubular electrode carrier, through which an electrolyte inflow line (10) is provided, the electrode carrier having on the front end a closure (13, 18), which is arranged such that the electrolyte inflow line in the axial direction of the electrode carrier is closed, and at least one outlet opening (19) being arranged in the radial direction. Also disclosed is a self-centering electrode arrangement and an installation for the defined rounding or deburring of edges of electrically conductive components by means of electrochemical machining with at least one corresponding electrode arrangement and also a method using the electrode arrangements and the described installation.

Abstract: A method of electrochemical machining that includes the steps of: positioning a workpiece and a tooling piece in a first position; moving at least one of the workpiece and the tooling piece toward the other such that the workpiece and the tooling piece occupy a second position; moving at least one of the workpiece and the tooling piece away from the other such that the workpiece and the tooling piece occupy a third position; and during at least a portion of the moving of the workpiece and/or the tooling piece from the first position to the second position and from the second position to the third position, using a power supply to apply a voltage across a gap formed between the workpiece and the tooling piece.

Abstract: A process for preparing the cutting edge of a cutting tool having a rake face and a clearance face. The process comprises the elimination of material from the cutting edge by providing a series of rapidly recurring electrical spark discharges in a gap located between the tool edge and a counterface. The spark discharges vaporize and melt the tool edge to form a desired radius.

Abstract: An electro-thinning apparatus for removing excess metal from the surface metal layer of the substrate is provided. The apparatus includes an electrolysis bath, a transportation system, an anode roller, a cathode roller, and at least one shielding plate. The electrolysis bath contains an electrolysis liquid. The transportation system is disposed in the electrolysis bath for moving a substrate from an upstream end to a downstream end. The anode roller is disposed relative to the electrolysis bath and located upstream to the transportation system. The cathode roller is located above the transportation system and located downstream to the anode roller. The at least one shielding plate is located downstream to the cathode roller. During electrolysis, the anode roller contacts a surface metal layer of the substrate while the cathode roller is partly immersed in the electrolysis liquid and away from the surface metal layer of the substrate during electrolysis.

Abstract: The invention relates to a method for the production of aero-dynamic structures during the production of integrally bladed gas turbine rotors. Aerodynamic structures of an integrally bladed gas turbine rotor are produced on a rotor disk base body, whereon the end contours are precise, by removing material according to an electrochemical removal process, i.e. by means of an electrochemical machining (ECM)-process. The method comprises the following steps: a) preparing a rotor disk base body which is made of a material which is difficult to machine; b) removing the material which is between the blade wings until a specific dimension is obtained, according to a removal process; c) preparing at least one working electrode in order to finish at least one aerodynamic structure of an integrally bladed gas turbine rotor.

Abstract: The present invention relates to electrochemical machining (ECM) of conductive materials and can be used for manufacturing stamps, mould tools and other workpieces of complex shape at the finishing stage of the machining process. Method for electrochemical machining with an oscillating machining electrode comprises the step of applying rectangular microsecond current pulses synchronized with the moment when a machining electrode and workpiece electrode are moved to a minimum distance towards each other. During the machining process, the amplitude of current pulses is increased and the pulse duration is adjusted in such a manner that the trailing edge of each pulse corresponds to the moment of maximum electrical conductivity of the interelectrode gap, the amplitude being increased until a predetermined roughness of the surface to be machined is achieved.

Abstract: A system and method for electrochemically machining a work-piece contains a fixture capable of receiving a work-piece and securing the work-piece to the fixture. An electrolyte source is also provided. In addition, the system contains a rotary drive subassembly capable of receiving a portion of the work-piece therein, motion of the rotary drive assembly being determined by a received control signal, wherein frequency and amplitude of the control signal increases and decreases motion of the rotary drive subassembly, and wherein the control signal is a trapezoidal waveform.

Abstract: An apparatus and method for adapting a CNC milling machine for electroerosion machining. The apparatus includes a tubular electrode on the distal end of an adapter shaft. A tool holder on the proximal end of the adapter shaft is mountable in the chuck of a cutter spindle in the milling machine. The adapter shaft is rotatably mounted within a bearing and an electrical brush contact subassembly, both of which are supported by a bracket. The bracket is attached to the milling machine but insulates it from the tool electrode. The bearing supports the adapter shaft in alignment with the CNC spindle. An electrical power supply energizes the electrode and the workpiece for electroerosion in a gap between them. Electrolyte is circulated through the spinning tool electrode during operation. The CNC computer is configured to operate the machine, power supply, and electrolyte flow for electroerosion machining.

Abstract: First and second electrodes are disposed at first and second locations, respectively, proximate to a periphery of a wafer support, wherein the first and second location are substantially opposed to each other relative to the wafer support. Each of the first and second electrodes can be moved to electrically connect with and disconnect from a wafer held by the wafer support. An anode is disposed over and proximate to the wafer such that a meniscus of electroplating solution is maintained between the anode and the wafer. As the anode moves over the wafer from the first location to the second location, an electric current is applied through the meniscus between the anode and the wafer. Also, as the anode is moved over the wafer, the first and second electrodes are controlled to connect with the wafer while ensuring that the anode does not pass over an electrode that is connected.

Abstract: A method for machining a blank includes machining a first pocket in the blank having a first sidewall, machining a second pocket in the blank, machining a groove within material located between the first and second pockets to expose a second sidewall opposite the first sidewall, machining the first and second sidewalls, and alternately repeating machining the grove and the sidewalls to step mill the groove deeper in the blank and form a third pocket along which the second sidewall extends.

Abstract: An electrolytic processing apparatus which, while eliminating a CMP processing entirely or reducing a load on a CMP processing to the least possible extent, can process and flatten a conductive material formed in the surface of a substrate, or can remove (clean) extraneous matter adhering to the surface of a workpiece such as a substrate. The present invention includes an electrode section including a plurality of electrode members disposed in parallel, each electrode member including an electrode and an ion exchanger covering the surface of the electrode, a holder for holding a workpiece, which is capable of bringing the workpiece close to or into contact with the ion exchanger of the electrode member, and a power source to be connected to the electrode of each electrode member of the electrode section. The ion exchanger of the electrode member includes an ion exchanger having an excellent surface smoothness and an ion exchanger having a large ion exchange capacity.

Abstract: A method and apparatus separates recoverable components (210) from conductive matrix composites (200) for further use or reuse. In an embodiment, the process uses an electrochemical apparatus that includes a cathode (220) and an anode. The conductive composite is electrically connected to the anode, and a non-acidic electrolyte (250) is supplied to an inter-electrode gap between the cathode and the anode.

Abstract: An electrolytic processing apparatus can increase the efficiency of the dissociation reaction of water and efficiently perform electrolytic processing, and can eliminate the need for an operation of a change of ion exchanger. The electrolytic processing apparatus includes: a processing electrode and a feeding electrode; a liquid supply section for supplying a liquid containing an ion-exchange material between the workpiece and at least one of the processing electrode and the feeding electrode; a power source for applying a voltage between the processing electrode and the feeding electrode; and a drive section for moving the workpiece and at least one of the processing electrode and the feeding electrode relative to each other; wherein electrolytic processing of the workpiece is carried out while keeping the workpiece not in contact with but close to the processing electrode at a distance of not more than 10 ?m.

Abstract: The invention relates to a method for the production of aero-dynamic structures during the production of integrally bladed gas turbine rotors. Aerodynamic structures of an integrally bladed gas turbine rotor are produced on a rotor disk base body, whereon the end contours are precise, by removing material according to an electrochemical removal process, i.e. by means of an electrochemical machining (ECM)-process. The method comprises the following steps: a) preparing a rotor disk base body which is made of a material which is difficult to machine; b) removing the material which is between the blade wings until a specific dimension is obtained, according to a removal process; c) preparing at least one working electrode in order to finish at least one aerodynamic structure of an integrally bladed gas turbine rotor.

Abstract: When forming metallic components, in particular three-dimensionally curved blades, which constitute a single piece with the blading of turbomachine rotor wheels, the linear oscillation of the electrode acting as a tool is superimposed by a circular oscillation, enabling the electrode to turn into the workpiece conformally with its shape. Further forming is performed by circular oscillation with circular feed in the one and/or the other direction. An embodiment of the corresponding apparatus comprises an electrode holder (9) with linear feed (Zvor) and linear oscillation (Zosz) and a workpiece holder (5) with circular oscillation (Cosz) and circular feed (Cvor).

Abstract: Substantially uniform deposition of conductive material on a surface of a substrate, which substrate includes a semiconductor wafer, from an electrolyte containing the conductive material can be provided by way of a particular device which includes first and second conductive elements. The first conductive element can have multiple electrical contacts, of identical or different configurations, or may be in the form of a conductive pad, and can contact or otherwise electrically interconnect with the substrate surface over substantially all of the substrate surface. Upon application of a potential between the first and second conductive elements while the electrolyte makes physical contact with the substrate surface and the second conductive element, the conductive material is deposited on the substrate surface. It is possible to reverse the polarity of the voltage applied between the anode and the cathode so that electro-etching of deposited conductive material can be performed.

Abstract: An electrochemical machining apparatus comprises a machining chamber for holding ultrapure water, a cathode/anode immersed in the ultrapure water held in the machining chamber, and a workpiece holding portion for holding a workpiece at a predetermined distance from the cathode/anode so that a surface, to be machined, of the workpiece is brought into contact with the ultrapure water. The electrochemical machining apparatus further comprises an anode/cathode contact brought into contact with the workpiece held by the workpiece holding portion so that the workpiece serves as an anode/cathode, a catalyst having a strongly basic anion exchange function or a strongly acidic cation exchange function, a power source for applying a voltage between the cathode/anode and the workpiece, and a moving mechanism for relatively moving the workpiece and the catalyst. The catalyst is disposed between the cathode/anode and the workpiece held by the workpiece holding portion.

Abstract: A tandem blisk is mounted in a multiaxis electrochemical machine. A first row of blades is electrochemically machined in sequence. A second row of blades is then electrochemically machined in sequence while the blisk is still mounted in the machine. The machine is initially set up for machining both stages without removal of the blisk between the machining sequences.

Abstract: An apparatus, method and means is provided for electrochemical machining of hydrodynamic bearing assemblies in spindle motors. In an aspect, a cartridge is provided that receives and accurately positions an electrode in three dimensions in a near frictionless manner. The electrode reaches and maintains an equilibrium position in response to a first and second predetermined force, the equilibrium position being a predetermined three dimensional orientation relative to the work piece and defining a critical orifice with the work piece. In an aspect, a hydrostatic bearing is employed within the electrode for radially adjusting the electrode.

Abstract: A method for selectively removing a layer of electrolytically dissoluble metal such as copper overplate from a substrate such as a low-k dielectric comprising: providing a substrate bearing on a major surface thereof a layer of electrolytically dissoluble metal, the metal layer serving as a dissoluble electrode and having a central region and an adjacent peripheral region; providing at least a first counterelectrode and a second counterelectrode; positioning the counterelectrodes opposite the metal layer and spaced from the metal layer and spaced from each other; in a first electrolytic step, passing an electric current between the first counterelectrode and the central region of the metal layer, wherein the first counterelectrode is cathodic with respect to the metal layer, and the first electrolytic step includes a first phase, a second phase, and a third phase and during the first phase the electric current is a low amperage current, during the second phase the electric current includes a train of anodi

Abstract: An apparatus for processing a material on a wafer surface includes a cavity defined by a peripheral wall and configured to direct a process solution and direct it to the surface to to a first wafer surface region without being directed to a second wafer surface region, a head configured to hold the wafer so that the surface of the wafer faces the cavity, and an electrical contact member positioned outside the cavity peripheral wall and configured to contact the second wafer surface region extending beyond the cavity, when the wafer is moved relative to the contact member. Advantages of the invention include substantially full surface treatment of the wafer.

Abstract: A profiled tube (50b) comprising a high carbon content alloy (greater than 0.3%), superalloy or other high creep strength material, has a fluted bore with internal fins (52b) and intervening valleys or troughs (56b). Such a tube is made by centrifugal casting and subsequent electrochemical machining by drawing of an electrode (104) along the tube while at the same time passing electrolyte along the tube and around the electrode and also applying an electrical current between the tube and electrode, so that material of the tube passes into solution in the electrolyte. The electrode (104) has the same profile as the end-profile required in the tube (80) but has an inclined working face (124). An electrode rod (92) drives the electrode from one end mounting means (82) to another (84), each of which support the tube (80) and supply/exhaust electrolytic solution. The electrolyte is preferably sodium nitrate, although an acid based system is feasible.

Abstract: A drive head for a bolt, fastener, coupling, nut or other driveable head made from a less malleable metal such as a powder metal nickel alloy. The drive head has an upper drive portion having at least six convex corners spaced around the outer periphery thereof, each corner terminating in an edge. The drive head also has a lower flange portion adjacent to the drive portion and having an edge extending radially outwardly to at least the edge of each corner. The drive portion and the flange portion of the drive head is formed by subjecting a blank having a generally circular head to electrochemical machining (ECM). A tool is also provided for the ECM method to form the drive portion and flange portion of the drive head.

Abstract: Deposition of conductive material on or removal of conductive material from a workpiece frontal side of a semiconductor workpiece is performed by providing an anode having an anode area which is to face the workpiece frontal side, and electrically connecting the workpiece frontal side with at least one electrical contact, outside of the anode area, by pushing the electrical contact and the workpiece frontal side into proximity with each other. A potential is applied between the anode and the electrical contact, and the workpiece is moved with respect to the anode and the electrical contact. Full-face electroplating or electropolishing over the workpiece frontal side surface, in its entirety, is thus permitted.

Abstract: An electrochemical machining technique involves moving a cathode (2) towards an anodic workpiece (1). A current is passed through an electrolyte which flows between the cathode (2) and workpiece (1) so as to cause material to be removed electrolytically from the workpiece (1). A vibratory movement is imposed on the cathode (2) and the current passed between the cathode (2) and workpiece (1) is also varied. The vibratory movement may consist of a main sinusoidal oscillation and a secondary ultrasonic vibration, and the current variation is synchronized with the main vibration so that current pulses, and ultrasonic vibration pulses, coincide, with a predetermined small phase shift, with peaks of the main vibration corresponding to the smallest gap between the cathode (2) and workpiece (1).

Abstract: In one aspect of the invention, an apparatus for ECM grooving of a workpiece is provided. A portion of a conical workpiece is supported on a frame, with the cone opening facing a Z-axis. A slide electrode assembly is provided, including an electrode movable along the Z-axis and having, on a face aligned across a machining gap from the workpiece, a pattern of grooves to be defined on the workpiece; As an electrolyte is pumped into or through the machining gap at a constant static pressure, the electrode reacts to the pressure by moving toward or away from the workpiece to establish a certain gap width to create the necessary groove depth and definition. The force acting on the slide electrode assembly is the primary controlling factor for establishing the machining gap as the electrode and support move in response to the constant static pressure of pumped electrolyte.

Abstract: The present invention pertains to apparatus and methods for electroplanarization of metal surfaces having both recessed and raised features, over a large range of feature sizes. The invention accomplishes this by use of a flexible planar cathode and a spacing pad thereon. Methods of the invention are electropolishing methods. During electroplanarization, the flexible planar cathode conforms to the global contour of the work piece (e.g. a wafer) while the spacing pad conforms to local topography of the metal layer being planarized. In this way, dishing is reduced in the final planarized metal layer.

Abstract: A carrier head for holding a workpiece during processing of a workpiece surface is provided. The carrier head includes a carrier housing, a base and a pressure member. The base is configured to hold the workpiece and is movable with respect to the carrier housing. The pressure member is between the base and the carrier housing and is configured to induce the base to apply a predetermined force onto the process surface.

Abstract: An electrochemical machining apparatus comprises a machining chamber for holding ultrapure water, a cathode/anode immersed in the ultrapure water held in the machining chamber, and a workpiece holding portion for holding a workpiece at a predetermined distance from the cathode/anode so that a surface, to be machined, of the workpiece is brought into contact with the ultrapure water. The electrochemical machining apparatus further comprises an anode/cathode contact brought into contact with the workpiece held by the workpiece holding portion so that the workpiece serves as an anode/cathode, a catalyst having a strongly basic anion exchange function or a strongly acidic cation exchange function, a power source for applying a voltage between the cathode/anode and the workpiece, and a moving mechanism for relatively moving the workpiece and the catalyst. The catalyst is disposed between the cathode/anode and the workpiece held by the workpiece holding portion.

Abstract: A method for production of a rotor for centrifugal compressor, wherein the said rotor is produced from a monolithic disc, which is provided with a central hole. The method consists of use, within an isolating medium, of at least one first electrode which has polarity opposite the polarity of the rotor, wherein the said first electrode operates starting from the outer diameter of the monolithic disc, in order to produce the blades and the cavities of the said rotor, and wherein the processing takes place with a continuous path, consisting of a first step of roughing, followed by a second step of finishing with a tool which has a shape similar to that of the electrode used for the first roughing step, in order to produce an accurate geometry of the blades.

Abstract: An electrochemical machining process gives a workpiece such as a honeycomb panel a 3-dimensional profile form having a varying cross-section perpendicular to an axis of the profile form. In the process an electrode is maintained in a constant position relative to the axis and the surface of the profile form is exposed differentially to the action of the electrode in the axial direction to vary the amount of material removal and so vary the cross-section.

Abstract: According to this dynamic pressure groove processing method, dynamic pressure grooves are formed in specified regions by electrochemical machining with the electrode of an electrode tool put close to a workpiece in the initial stage. Through this electrochemical machining, corners of land portions adjacent to the dynamic pressure grooves can be curved and smoothed. Next, by subjecting the workpiece to electrochemical machining with the electrode of the electrode tool put away from the workpiece, the land portions are to undergo weak electrochemical machining. Surface roughness of surfaces of the land portions can be reduced, and the curved corners of the land portions can be made smoother at the same time. Therefore, the abrasion resistance characteristic of the dynamic pressure grooves can be improved further than that achieved by the conventional electrochemical machining, allowing the abrasion resistance characteristic and reliability to be sufficiently improved.

Abstract: Deposition of conductive material on or removal of conductive material from a wafer frontal side of a semiconductor wafer is performed by providing an anode having an anode area which is to face the wafer frontal side, and electrically connecting the wafer frontal side with at least one electrical contact, outside of the anode area, by pushing the electrical contact and the wafer frontal side into proximity with each other. A potential is applied between the anode and the electrical contact, and the wafer is moved with respect to the anode and the electrical contact. Full-face electroplating or electropolishing over the wafer frontal side surface, in its entirety, is thus permitted.

Abstract: A workholder for an ECM process comprises a set of jaws which define an interior workpiece holding region are mounted on the surface of a diaphragm which is movable under air pressure from a flat to a more generally spheroid shape with the injection of pressurized air between the diaphragm and a backing plate. As the air is injected, and the diaphragm becomes more spheroid, the jaws are moved a substantially equal distance away from the center axis of the workholding region. The workpiece, which typically incorporates or is mounted on a circular shaft, is placed in the center of the workholding region, and the air pressure is removed, causing the diaphragm to return to its original flat shape and the jaws to snap back to their original positions resting against the shaft.

Abstract: A method of electrochemically machining an electrically conductive workpiece in an electrolyte by applying electrical pulses between the workpiece and an electrically conductive electrode, one or more machining pulses alternating with passivation voltage pulses for depositing passivation layers on the workpiece. The amplitude of the passivation voltage pulses is adjusted during an adjustment procedure in which the amplitude of the passivation voltage pulses is increased gradually from zero to the voltage at which the workpiece starts to dissolve in the electrolyte. After each voltage increase the resistance of the gap between the electrode and the workpiece is measured. The voltage value for the highest gap resistance is stored in a memory and used during further machining. The time span of the passivation voltage pulses may be divided into time slices and for each time slice the voltage is adjusted for maximum gap resistance during that time slice.

Abstract: A sacrificial cores in castings of metallic or non-metallic materials is made from a metal that can be electrolytically dissolved, and is removed from the casting by electrochemical machining. The sacrificial core may be a hollow shell incorporating an integral electrode within the shell and electrically insulated from the shell.

Abstract: In a method for electrochemical machining, the working distance is set by contacting the workpiece with the electrode, increasing the distance between the workpiece and the electrode by a first distance, detecting whether the contact between the electrode and the workpiece is broken, and further increasing the distance between the workpiece and the electrode by a second distance. Owing to this method, very small working distances can be set with a limited risk of short-circuiting and flash-over.

Abstract: Method of manufacturing a bearing ring (1) for a bearing such as a ball bearing or cylindrical roller bearing, wherein the bearing ring (1) is rotated around an axis (6) and the amount of material removed is controlled by the choice of the cross section of an electrode (3) parallel to the surface of the raceway under the electrode (3). Thus the radius of the groove (2) is kept constant. An electrode with a suitably adapted convex cross section allows for the manufacture of bearing rings within a very narrow specification range. Thus the invention also relates to a bearing comprising an electrochemically machined bearing ring (1) according to the invention having excellent operational life and characteristics.

Abstract: In the electrochemical drilling of a hole completely through a workpiece, the present invention proposes operating the power supply in a current regulating mode. Initially, a hollow cathode is positioned adjacent to a workpiece in which one or more holes are to be drilled. An electrolyte is flowed through the cathode and against the workpiece. A constant electrical current is applied between the cathode and the workpiece across the electrolyte. Then the cathode is advanced at a constant rate toward the workpiece for the drilling of the hole(s), while maintaining the electrolyte flow and current substantially constant.

Abstract: An electrochemical machining method in which a work piece and a machining electrode are opposed to each other and dipped in an electrolyte solution, and a surface of the work piece is machined by causing an electrolytic reaction between the surface of the work piece and a tip of the machining electrode in a state where a separating distance between the surface of the work piece and the tip of the machining electrode is adjusted and a desired separating distance is maintained, wherein a zero contact reference position where the surface of the work piece and the tip of the machining electrode are brought into contact with each other and the separating distance between the work piece and the machining electrode is nullified is electrically detected, moving distances of the work piece and the machining electrode from the zero contact reference position are detected, a relative separating distance between the surface of the work piece and the tip of the machining electrode is calculated based on a result of the de

Abstract: An electrochemical machining method and apparatus involves the passage of a wire through a programmably controllable electrochemical machine, wherein the wire is tapered along its length to obtain a desired profile. The rate of material removal may be determined, for example, by modulating the power supplied to the electrochemical machine, or by varying the wire speed therethrough. The machine can include an electrical contact cell and a nutation cell. Electrical power is coupled to the wire via the contact cell. Relative orbital motion of the wire and the nutating cell ensures that material removal from the wire is uniform in all directions.

Abstract: A method for performing fine working of a material by electrochemical reaction comprises a two-step scanning operation in which a surface topography of the material is obtained during a first scan which is used to control the position of a probe during a second scan in which an electrochemical reaction is performed. During the first scan, an electrochemical cell is constructed with a four-electrode system, including the probe, a material to be worked, a reference electrode and a counter electrode. The potential of each of the probe and the material to be worked is set so that no electrochemical reaction occurs during the first scan. Data representative of the surface topography is stored and used to control the position of the probe during the second scan in which an electrochemical cell is constructed with a three-electrode system, including the probe, the material, and the reference electrode.

Abstract: Method of electrochemically machining an electrically conductive workpiece (2) in an electrolyte by applying bipolar electric pulses between the workpiece (2) and an electrically conductive electrode (6), one or more current pulses of normal polarity alternating with voltage pulses of opposite polarity. The amplitude (Un) of the voltage pulses is adjusted between two predetermined values (Un1, Un2) derived from the occurrence of a given surface quality of the workpiece (2) and the occurrence of wear of the electrode (6). The derivation is effected by means of at least one test which precedes the machining of the workpiece (2). During the test the amplitude (Un) of the voltage pulses is increased gradually from an initial value to a final value. The two predetermined values (Un1, Un2) are determined upon the occurrence of a sign reversal in the difference between successive values of a parameter which is representative of a property of a gap (5) between the electrode (6) and the workpiece (2).

Abstract: A halogenated polymeric material is exposed to a reducing agent and/or an electrolyte and applied voltage to render exposed portions capable of being metallized and of being etched. The exposed portions can also be doped to thereby induce electrical conductivity therein. Also, new structures containing a free standing halogenated polymeric-containing layer and electrical conductive pattern thereon are provided.

Abstract: A method of machining the surface of an electrically conductive workpiece by application of a voltage to an electrically conductive tool spaced apart from the workpiece and moving the tool to shape or pattern the workpiece wherein variable flow of fluid is provided in the space between the tool and the workpiece. The fluid contains suspended insoluble interactive particles that are electrically conductive or are ionically conductive, but electronically insulating. The suspended particles came intermittent electrical short circuiting between the tool and the workpiece to prevent catastrophic and uncontrolled sparking or arcing during machining.

Abstract: The metal bond wheel forming apparatus includes rotation speed control means 11 for controlling the rotation speed of a grinding wheel 6; energy control means 9 for controlling discharge energy that is supplied to the gap between a wire electrode 1 and the grinding wheel 6; relative speed control means 17 for controlling a relative movement speed either for the wire electrode 1 or for the grinding wheel 6; and detailed machining control means 23 for controlling the rotation speed control means, the energy control means and the relative speed control means, for setting the rotation speed of the grinding wheel and discharge energy appropriate for detailed machining, and for setting the relative movement speed for the wire electrode or for the grinding wheel to enable high speed shaping during the detailed machining.