METHOD OF MAKING COATINGS Russian patent published in 2005 - IPC

FIELD: mechanical engineering.

SUBSTANCE: method comprises oxidizing an article made of zirconium or its alloys in acidic electrolytes. The oxidizing is performed in the micro-arc regime at a constant current for 5-30 min at a current density of 5-20 A/dm³ and a voltage of 350-500 V in a combined electrolyte on the basis of oxalic acid, 20-50 g/l, lemon acid, 20-80 g/l, and ammonium hydrofluoride, 0.8- 2.5 g/l with subsequent heating of the article up to a temperature within the range from 800 to 1050°C, allowing to stand during 20-30 min, and cooling in ambient air.

EFFECT: increased thickness and quality of the oxide coating.

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