METHOD FOR PREPARING SURFACE OF MAGNETIC ALLOY COMPRISING RARE EARTH ELEMENTS BEFORE APPLYING ELECTROPLATING Russian patent published in 2024 - IPC C25D5/34 C23F1/28 C23G1/02 

FIELD: galvanic coatings on magnetic alloys comprising rare earth elements.

SUBSTANCE: invention relates to chemical surface treatment before applying galvanic coatings. The method includes the first etching in an aqueous solution of hydrochloric acid comprising 300-700 ml/l for 1-3 s at a temperature of 50-70°C, and the second etching in an aqueous solution with the following ratio of components: nitric acid 150-350 ml/l, sulfuric acid 150-350 ml/l, sodium chloride 1-10 g/l, sodium nitrate 1-10 g/l, water deionized 180-698 ml/l, which is carried out for 7-10 s at a temperature of 18-25°C. After the first and second etching, rinsing in cold water is done for 5-10 s.

EFFECT: adhesion strength of the surface of a magnetic alloy comprising rare earth elements to the galvanic coating and the quality of the galvanic coating.

1 cl, 3 dwg, 1 ex