Abstract

The invention relates to technological equipment for the electrochemical machining, using a vibrating electrode tool, of stamps, press moulds, and fins of turbine and compressor blades, and also for electrochemical engraving. The device comprises: a feed drive comprising a motor, a traction device in the form of a screw/nut pair, and a motion sensor; a hollow sleeve capable of vertical movement along the guides of a bifurcated column; and an electromechanical oscillator, which is mounted at the lower end of the hollow sleeve. Furthermore, the neck of an eccentric shaft of the electromechanical oscillator having a connecting rod head mounted on bearings is arranged inside a frame suspended on centring membranes with the possibility of reciprocal motion in the feed direction of the electrode tool and bearing, on opposite sides, an electrode holder and a compensator bush with a rigidly fixed connecting rod stem. This device makes it possible to increase the accuracy of electrochemical machining using a vibrating electrode tool by virtue of reducing elastic and temperature-related deformations resulting in an inaccuracy of the position of the electrode tool relative to the semifinished product.

IPC Classes  ?

• B23H 7/26 - Apparatus for moving or positioning electrode relatively to workpieceMounting of electrode
• B23H 7/32 - Maintaining desired spacing between electrode and workpiece

Abstract

The invention relates to electrolyte purification and can be used for supplying and regenerating an electrolyte during electrochemical processing. In the present method, toxic chromium compounds in an electrolyte are neutralized, wherein in a first phase of the process, the hydrogen ion exponent of the electrolyte is reduced to a value of pH 1, corresponding to an acidic medium. In a second phase, the value of the hydrogen ion exponent of the electrolyte is maintained at pH1 and a dose of a reagent which neutralizes the toxic chromium compound is injected, the change in the oxidation-reduction potential is monitored and if the value thereof increases, another reagent dose is injected. The process is repeated until the oxidation-reduction potential remains unchanged or decreases over a sufficiently long period of time. In a third phase, the value of the hydrogen ion exponent of the electrolyte is increased to a preset level of рН2. The invention provides environmentally friendly electrochemical processing technology, improves the quality of electrolyte purification, and makes it possible to automatically remove toxic ions from a spent solution and neutralize hexavalent chromium in an electrolyte solution without prior separation of sludge.

IPC Classes  ?

• B23H 1/10 - Supply or regeneration of working media
• B23H 3/10 - Supply or regeneration of working media
• C25D 21/18 - Regeneration of process solutions of electrolytes

Abstract

The invention relates to electrochemical dimensional processing of parts consisting of chromium-containing steels and alloys. First, processing of a part is implemented by working current pulses of direct polarity, and then said current pulses and the power supply to a tool electrode are switched off, wherein a group of high-frequency test current pulses of direct polarity is switched on, and the value of the residual polarization in the interelectrode space is measured. Then, current pulses of reverse polarity are switched on and are fed synchronously with the phase of maximum convergence of the oscillating tool electrode and the part, and deposition of chromium onto the surface is performed, with alternation of the current pulses of reverse polarity with high-frequency test current pulses of direct polarity, wherein the deposition of chromium is controlled on the basis of the increase in the value of the residual polarization relative to the value thereof after processing with working current pulses of direct polarity. The invention makes it possible to increase the processing quality by means of providing a layer with a high lustre on a processed surface and to reduce the concentration of toxic hexavalent chromium ions in the processed electrolyte solution.

IPC Classes  ?

• B23H 3/00 - Electrochemical machining, i.e. removing metal by passing current between an electrode and a workpiece in the presence of an electrolyte

Abstract

The invention relates to the electrochemical machining of metals and alloys, said machining being intended for forming a regular nanometric and micrometric layer on an intricately shaped surface. The electrochemical machining is carried out in neutral electrolytes in small interelectrode clearances with the use of current pulses which are synchronized with oscillation phases of an electrode instrument, the phases corresponding to the maximum pressure of the electrolyte in the interelectrode gap. The approach velocity of the electrodes is selected such that the maximum amount of pressure of the electrolyte in the interelectrode gap P(t)max does not exceed the permissible maximum amount of pressure of the electrolyte in the interelectrode gap [Pmax]. At P(t)max being greater than [Рmах], the approach velocity of the electrodes is reduced, and, at P(t)max being less than [Рmах], the approach velocity of the electrodes is increased, maintaining the amount of maximum pressure of the electrolyte in the interelectrode gap P(t)max within the range of P(t)max > 0.8 [Pmax] and P(t)max < [Рmах]. Such a selection of the approach velocity of the electrodes makes it possible to increase the accuracy and efficiency of electricochemical machining by a vibrating electrode instrument by creating the possibility of supplying current pulses at the instant at which an optimum combination of interelectrode clearance and greatest electrolyte pressure is achieved.

IPC Classes  ?

• B23H 3/02 - Electric circuits specially adapted therefor, e.g. power supply, control, preventing short circuits