Abstract: While switching polarity of an electrode, a voltage is applied between the electrode and a workpiece hard metal with the electrode used as a negative-electrode such that tungsten carbide (WC; component of the hard metal) is anodized to form a tungsten oxide (WO3), and a voltage is supplied therebetween with the electrode used as a positive-electrode such that cobalt (Co) that is a component of the workpiece is electrolytically-eluted and at the same time the WO3 generated by anodization is dissolved in the machining fluid, a saline solution (NaCl) or an aqueous solution of nitrate of soda (Na(No3)) is used as an machining fluid; a calcium salt is added beforehand to the machining fluid to react tungstate soda (Na2WO4) generated in the machining with the calcium salt whereby calcium tungstate (CaWO4) is produced; and a calcium compound is separated and recovered using a difference in specific gravity.

Abstract: A microshaft forming method and apparatus for forming a microshaft without requiring high level of stillness required by conventional methods. The microshaft forming apparatus comprises an elongated electrode (1) to be formed into a microshaft, a forming plate (3) for forming the electrode (1), electrode rotating means for rotating the electrode (1) around the length direction (1a) of the electrode (1), a discharge machining power supply (5) for applying a voltage between the electrode (1) and the forming plate (3) to cause discharge between the electrode (1) and the forming plate (3), and electrode moving means for traversing the electrode (1) rotated by the electrode rotating means across the forming plate (3) from the side edge surface (3a) of the forming plate (3).

Abstract: An electric discharge machine for machining a workpiece (2a) made of insulating material or other materials comprises: a first comparison member (17) for comparing voltage (V) between the electrodes of the electrode (1) and the workpiece (2a) with the first reference voltage (V1) which is set at a value close to electric power source voltage (V0) not higher than electric power source voltage (V0); a second comparison member (18) for comparing voltage (V) between the electrodes with the second reference voltage (V2) which is set at a value lower than the first reference voltage (V1); and a control member (19) for setting a short electric discharge pulse width (TP1) in the case where voltage (V) between the electrodes is lower than the second reference voltage (V2) according to the result of comparison conducted by the second comparison member (18) at a point of time when a predetermined period of time (T0) has passed from the time when voltage (V) between the electrodes becomes lower than the first reference v

Abstract: Powder of a simple substance or a combination of a plurality of carbides of metals belonging to the IVa, Va and Via families in the Periodic Table is mixed with a ferrous-family metal powder or non-ferrous metal powder having the same composition as the treatment target (2) as a simple substance or a combination of a plurality of metals, and this is compressed and molded, and incompletely sintered to form an electrode (12) serving as a discharge processing electrode; and said device is provided with a switching unit which alters electrical conditions at the time when the base member of the treatment target (2) is directly subjected to a discharging surface treatment and the electrical conditions at the time when a coating film (13) that has been formed is subjected to a discharging surface treatment according to the characteristics of the treatment target material.

Abstract: In an electric discharge machine, wherein electric power is supplied between an electrode and a workpiece to machine the workpiece, a jumping motion is performed to temporarily increase a distance between the electrode and the workpiece. The electric discharge machine includes a detector for detecting a machining reaction force; a setting unit for setting a specified value of the machining reaction force; a comparator for comparing a detected value of the machining reaction force with a specified value of the machining reaction force; and a changing unit for changing a locus of the jumping motion so that the machining reaction force can be reduced if the comparator finds that the detected value of the machining reaction force is greater than the specified value of the machining reaction force.

Abstract: An electric discharge machine for machining a workpiece (2a) made of insulating material or other materials comprises: a first comparison member (17) for comparing voltage (V) between the electrodes of the electrode (1) and the workpiece (2a) with the first reference voltage (V1) which is set at a value close to electric power source voltage (V0) not higher than electric power source voltage (V0); a second comparison member (18) for comparing voltage (V) between the electrodes with the second reference voltage (V2) which is set at a value lower than the first reference voltage (V1); and a control member (19) for setting a short electric discharge pulse width (TP1) in the case where voltage (V) between the electrodes is lower than the second reference voltage (V2) according to the result of comparison conducted by the second comparison member (18) at a point of time when a predetermined period of time (T0) has passed from the time when voltage (V) between the electrodes becomes lower than the first reference v

Abstract: An electric discharge machining apparatus for supplying machining electric power to a gap between an electrode (1) and a workpiece (2). The apparatus includes a gap dimension detection device (8) for detecting a dimension of the gap, a gap average voltage detection device (11) for detecting an average voltage of the gap, a gap dimension correction device (13) for correcting the dimension of the gap, and a gap dimension correction starting device (12) for starting the gap dimension correction device (13) when a first comparison between a detected gap dimension and a predetermined allowable value and a second comparison between a detected gap average voltage and a predetermined reference average voltage are made and the gap dimension detected by the first comparison is larger than the predetermined allowable value and the gap average voltage detected by the second comparison is smaller than the predetermined reference average voltage.

Abstract: An electric discharge machine in which electric power for machining is supplied by a machining electric power supply means (13) to between an electrode (1) and a workpiece (2) provided in a machining solution (3), electric discharge machining is conducted on the workpiece (2) while the electrode (1) and the workpiece (2) are relatively being moved by a positioning means, and a jumping motion is conducted, the electric discharge machine comprising: a machining reaction force detecting means (20, 21, 22) for detecting a machining reaction force; a machining reaction force specified value setting means (23) for setting a specified value of the machining reaction force; a machining reaction force comparing means (24) for comparing a detected value of the machining reaction force, which is detected by the machining reaction force detecting means (20, 21, 22), with a specified value of the machining reaction force which is set by the machining reaction force specified value setting means (23); and a motion locus ch

Abstract: An electric discharge is generated between an electric discharge surface treatment electrode and a wire electrode, and an electric discharge surface treatment material is stuck on the surface of the wire electrode by the energy of the electric discharge. An electric discharge is then generated between a work piece and the wire electrode on which the electric discharge surface treatment material is stuck, and a surface modified layer is formed on the surface of the work piece by the energy of the electric discharge.

Abstract: Powder of a simple substance or a combination of a plurality of carbides of metals belonging to the IVa, Va and VIa families in the Periodic Table is mixed with a ferrous-family metal powder or non-ferrous metal powder having the same composition as the treatment target (2) as a simple substance or a combination of a plurality of metals, and this is compressed and molded, and then preliminarily sintered to form a sintered electrode (12) serving as a discharge processing electrode; and said device is provided with a switching unit which alters electrical conditions at the time when the base member of the treatment target (2) is directly subjected to a discharging surface treatment and the electrical conditions at the time when a hard coat film (13) that has been formed is subjected to a discharging surface treatment according to the characteristics of the treatment target material.

Abstract: A casting process for producing a metal matrix composite comprising a first phase or a matrix of a metal or metal alloy and a second phase of particles dispersed in the matrix, comprising the steps of: preparing a melt of the metal or metal alloy in a vessel; feeding the particles to the melt; applying ultrasonic vibration to the melt while electromagnetically stirring the melt; and then causing solidification of the melt. The process preferably further comprises the step of applying ultrasonic vibration to the melt while electromagnetically stirring the melt during the solidification of the melt.

Abstract: A surface treating is performed by an electric discharge. The electric discharge is generated by applying a voltage between an electrode and a metal workpiece. The electrode is a solid or green compact electrode or the like which is made of a reforming material. The workpiece may be an end mill or the like. Then, a coating layer is formed on a surface of the metal workpiece. Thereafter, a nitriding treatment is performed on the coating layer in a nitriding vessel or the like. Thus, a hard coating layer of better quality is formed on the surface of the workpiece whether a material of the workpiece is steel or hard metal.

Abstract: An apparatus and process for forming surface layers on electrodes by electron discharge machining. A machining gap, between an electrode and a workpiece is filled with a dielectric mixture containing metallic or submetallic powder. The apparatus uses a swinging mechanism to move the electrode during processing. The apparatus uses a high-voltage superposition circuit to superpose a voltage of 100-400 V across the gap. The apparatus uses a current limiting resistor of 100-300 .OMEGA. to ensure that the main circuit supplies a low voltage of approximately 100 V to the machining gap. In a second embodiment, the apparatus prevents electrode cracking by dispersing the discharges throughout, and widening, the machining gap.

Abstract: An apparatus and process for forming surface layers on electrodes by electric discharge machining. A machining gap, between an electrode and a workpiece is filled with a dielectric mixture containing metallic or submetallic powder. The apparatus uses a swinging mechanism to move the electrode during processing. The apparatus uses a high-voltage superposition circuit to superpose a voltage of 100-400 V across the gap. The apparatus uses a current limiting resistor of 100-300.OMEGA. to ensure that the main circuit supplies a low voltage of approximately 100 V to the machining gap. In a second embodiment, the apparatus prevents electrode cracking by dispersing the discharges throughout, and widening, the machining gap.

Abstract: A surface treatment method and apparatus therefor for providing wear and corrosion resistance, which includes relatively rotating a modified metallic member to be surface modified and a block, which may be metal only or may include a modifying material (e.g., ceramic or W-C/Co), and generating electrical discharge between the block and the modified metallic member to form a modification layer on the surface of said modified metallic member. If the modifying material is not in the block, it can be supplied via a dielectric bath or spray at the discharge interface. In this manner, the cutting edges of a cutting tool with a complicated shape can be surface modified easily to carry out tool surface treatment which increases a cutting tool life greatly. Cutting and surface treatment can be performed alternately as determined by a controller.

Abstract: A process of detecting the position of generation of electric discharge between a discharge electrode of an electric discharge machine and a work. The process comprises the steps of branching a pulse discharge current into two or more branch power supply lines and supplying discharge current divisions to a discharge electrode from two or more points through the respective branch power supply lines, detecting the discharge current divisions in the branch power supply lines, calculating the peak value of each of the discharge current divisions at the time of rising of the pulse discharge current, standardizing the peak value of each of the discharge current divisions, and calculating electric discharge generation position according to the standardized peak value. In this process, the electric discharge generation position detection is performed without restriction imposed by the pulse length or by the electrode material.

Abstract: An apparatus for forming surface layers on electrodes by electric discharge machining. A machining gap, between an electrode and a workpiece is filled with a dielectric mixture containing metallic or submetallic powder. The apparatus uses a swinging mechanism to move the electrode during processing. The apparatus uses a high-voltage superposition circuit to superpose a voltage of 100-400 V across the gap. The apparatus uses a current limiting resistor of 100-300.OMEGA. to ensure that the main circuit supplies a low voltage of approximately 100 V to the machining gap. In a second embodiment, the apparatus prevents electrode cracking by dispersing the discharges throughout, and widening, the machining gap.

Abstract: A fitting of a first member into a second member is performed until an insertion depth becomes a predetermined value while applying ultrasonic vibration continuously to either or both of the members and, thereafter, the application of ultrasonic vibration is made intermittent.

Abstract: A method and apparatus for electric discharge machining whereby the total machining time to machine a workpiece through coarse, medium and finish surface roughness stages is significantly reduced. Machining condition data for the three surface roughness stages is stored in a memory. As the machining progresses, the surface roughness of the workpiece is monitored. If the surface roughness is found to exceed the reference level for the corresponding stage, machining using the present conditions is continued, whereas, if the surface roughness is below the reference level, the machining conditions are switched to those of the next stage.

Abstract: An ultrasonic machining method comprises the steps of causing a machining solution to readily produce a gas in the machining solution, supplying the machining solution around a workpiece to be machined, and producing an ultrasonic vibration to carry out an ultrasonic machining operation, wherein the gas is produced during the machining operation so that a machined surface of the workpiece is prevented from being degraded by the occurrence of cavitation. An ultrasonic machining apparatus comprise a heater for heating the machining solution or a DC power source for electrolyzing the machining solution.