74results about How to "Does not cause corrosion" patented technology

The invention relates to a pressure welding technique of a copper and aluminum joint, which is characterized by steps of: the blanking of a copper pipe and an aluminum pipe, the removal of burr and the washing of the surface of the copper pipe with acid; welding: a welding machine, an upper clamping mould and a lower clamping mould are adjusted; the copper pipe and the aluminum pipe are respectively clamped between the upper clamping mould and the lower clamping mould, the two ports for welding are extruded out of the clamping mould, the ends of the copper pipe and the aluminum pipe to be welded are heated to the temperature of about 420 to 540 DEG C and applied with the upsetting force of 0.4 to 0.8Mpa so as to cause the close contact of the welding surface of the copper pipe and the welding surface of the aluminum pipe, radial plastic deformation is generated by pressure, metal flashes are formed and a welding line is formed by the closely contacted pure metals, therefore, the welding process is finished; detecting welding beadings, removing residues and external burr; leak-checking: detecting whether the welded pipe has leakage by an air pressure test; drying and leak-checking with helium. The invention has simple technique and can reduce production cost and enhance production efficiency; since the oxidized film of the contact surface of the copper pipe and the aluminum pipeare damaged and extruded during pressure-increasing and deforming, the welded joint can be purified with good welding quality, no leakage, no deformation and long service life.