PHOSPHATISATION METHOD OF TITANIUM ALLOY SURFACE Russian patent published in 2012 - IPC C23C22/07 C25D11/36 

FIELD: metallurgy.

SUBSTANCE: method involves degreasing of surface, water washing, treatment of alloy surface with oxidative solution on the basis of mixture of nitric and hydrofluoric acids or with magnesium oxide, phosphatisation of titanium alloy surface by treatment using the solution containing phosphate and zinc ions, repetitive washing and drying. Titanium alloys are subject to anodic phosphatisation at action of direct current in the solution additionally containing potassium ions, at the following component ratio (g/l): PO₄ ^-3 10.5 - 12.5, Zn⁺² 3.5 - 4.5, K⁺¹ 1.0 - 1.5; at that, pH value of solution is maintained within the range of 4.0 - 5.0. Phosphatisation is performed at current density of 5-6 A/dm² during 4-6 minutes.

EFFECT: invention allows increasing adhesive ability of surface of parts from titanium alloys to lacquer coatings, reducing the duration of phosphatisation process and solution toxicity.

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