FLAT TUBE, HEAT EXCHANGER OF FLAT TUBES AND METHOD OF THEIR MANUFACTURING Russian patent published in 2011 - IPC B23K1/00 B23K101/14 

FIELD: technological processes.

SUBSTANCE: invention may be used to manufacture heat exchangers of tubes of flat shape with a channel for a flow that have low thickness of the wall. The flat tube may be formed from at least one sheet of aluminium alloy and has the first, second and third layers. The aluminium alloy of the third layer is anode relative to the aluminium alloy of the second layer, and in the second layer it is anode relative to the aluminium alloy of the first layer, at the same time the third layer is more resistant to silicon diffusion compared to the second layer. A rib is soldered with a solid braze to the wall of the flat tube by means of the fourth layer that contains a solid braze material. The wall and the layer of the material of solid braze has common thickness of not more than approximately 0.15 mm. When soldering with a solid braze, time or temperature of soldering is controlled provided there is diffusion of silicon via the third layer of the wall near to the material of the solid braze into the second layer of the wall to the depth that is less than its full thickness, to form accumulation of an intermetallic compound containing silicon.

EFFECT: high-quality soldered joints of tubes formed from the specified aluminium sheets ensure high resistance of heat exchangers to pitting corrosion.

24 cl, 96 dwg