METHOD OF FORMING OXIDE FILMS ON ALUMINUM AND ITS ALLOYS Russian patent published in 1998 - IPC

FIELD: coatings. SUBSTANCE: method includes formation of oxide coatings by way of anodizing samples of aluminum and its alloys in electrolytes, process being carried out in molten eutectic mixture of potassium and sodium nitrate mixture under potentiodynamic or galvanodynamic polarization conditions to form oxide coatings with desired thickness, which are further treated by plasma-spark discharge band. The latter is created in electrode-molten salt mixture-atmosphere air phase interface by increasing potential of sample anode to 130-150 V or current density to 100-200 mA/cm followed by gradually removing sample anode from melt with velocity 0.05 to 3 mm/s. EFFECT: optimized process parameters. 4 dwg