ALUMINUM TUBE HAVING MANY HOLES FOR HEAT EXCHANGER AND ITS MANUFACTURE

摘要

PURPOSE:To prevent the buckling of fins during brazing, to reduce the thickness of the fins and to make a heat exchanger light in weight by coating the surface of an extruded Al or Al alloy tube having many holes with Zn or a Zn alloy as a brazing filler metal. CONSTITUTION:A flux is applied to the surface of an extruded Al or Al alloy tube 1 having many holes, and the tube 1 is immersed fro 1-60 sec in a molten bath prepd. by melting Zn or a Zn alloy as a brazing filler metal at <=500 deg.C. The surface of the tube 1 is coated with the brazing filler metal 3 by hot dipping.