METHOD OF WELDING METALS AND ALLOYS Russian patent published in 1994 - IPC

FIELD: different metal joining. SUBSTANCE: method is based upon principle of producing liquid additive metal directly at welding process in a volume, limited by edges, being welded, and by forming attachments, for example a slag bath for welding aluminium represents a cryolite-alumina melt. At passing direct electric current through such melt with the aid of an electrode, immersed into it, electrolysis takes place in the slag bath. Ions, being formed and having electric charges, are being directed to respective surfaces with an opposite charge. Cations Al³⁺ are being accumulated near a tray, with blanks loaded, on it or near the forming devices, having negative charge. After neutralization of the cations the last form drops of liquid aluminium, collecting on the tray and creating a common metallic bath. Step by step with an increase of a volume of liquid aluminium the metallic bath is being displaced upwards, forming a welded joint. Upon welding of aluminium a system Na₃Alf₅-AlF₃-CaF₂-Al₂O₃ is selected as a slag bath; a melt, forming the electrolyte includes (mass %): cryolite 75-92, aluminium fluoride 2-10, calcium fluoride 1-10, aluminium oxide 5-10. A ratio of sodium fluoride and aluminium is no less than 3. Temperature of the electrolyte is sustained in range 930-960 C. EFFECT: enhanced quality of welded seams. 1 cl, 1 dwg, 1 tbl