METHOD OF PULSED ELECTROMACHINING Russian patent published in 2012 - IPC B23H3/00 

FIELD: process engineering.

SUBSTANCE: invention relates to electromachining and may be used in making complex shape surface of machine assembly units and parts of forming tooling from chromium-containing steels and alloys operated in aggressive media and at high friction. Proposed method comprises machining the part by current pulses timed to maximum approach between oscillating electrode and part with adjustment of electrode feed speed. First, machining if performed by forward-polarity current pulses to produce layer rich in chromium ions adjoining the part surface. Then, after preset part machining depth, shape and sizes are reached, forward-polarity current pulses and electrode feed are switched off. Then, train of test HF forward-polarity current pulses are switched on to measure residual polarisation in electrode gap. Then, reverse-polarity current pulses are switched on to be fed timed to maximum approach between electrode and part to perform cathodic deposition of chromium of part machine surface by alternating reverse-polarity pulses with said forward-polarity test pulses. Now, chromium deposition is controlled by increment of residual polarisation relative to its magnitude after processing by forward-polarity current pulses.

EFFECT: higher quality of machining, decreased concentration of hexavalent chromium toxic ions.

8 cl, 7 dwg, 1 ex