METHOD OF ELECTROLYTIC-PLASMA POLISHING OF ARTICLES FROM TITANIUM AND IRON-CHROMIUM-NICKEL ALLOYS Russian patent published in 2019 - IPC C25F3/16 

FIELD: technological processes.

SUBSTANCE: invention relates to electrolytic-plasma polishing of metal articles, mainly from titanium and iron-chromium-nickel alloys. Method involves immersion of part in electrolyte based on aqueous solution of hydrofluoric acid salt with concentration of fluorine ions from 0.12 mol/l to 0.23 mol/l, wherein salt used is ammonium fluoride, or sodium fluoride, or potassium fluoride, formation around the vapor-gas shell part, ignition of discharge and polishing till obtaining of specified roughness, at that temperature of electrolyte is installed by formula: T=(-222.4)*K(F^-)+122.0, where T is electrolyte temperature, in °C, K(F^-) is concentration of fluorine ions, mol/l, (-222.4) and 122.0 are empirical coefficients, wherein during polishing the electrolyte is cooled with maintaining the calculated temperature T±2.5 °C in range of 70–95 °C and concentration of fluorine ions K(F^-)±0.02 mol/l, and potential is applied to part from 270 V to 290 V, electrolyte is used, which contains acidity regulators to pH 4.5–6.5 and inorganic readily soluble salt of strong base and strong acid 0.4–0.5 mol/l.

EFFECT: invention increases polishing stability and increases the number of treatment cycles without correction of electrolyte composition and without loss of quality.

4 cl, 3 tbl, 1 ex