ALUMINUM HEAT EXCHANGER AND METHOD FOR PRODUCING ALUMINUM HEAT EXCHANGER

摘要

A method of protecting an aluminum surface from corrosion by forming a protective coating on said metal surface by the alkaline chromate method, the chromate method, the chromium phosphate method, the zinc phosphate method, the titanium phosphate method, the zirconium phosphate method or the chromic acid resin method, in which protective coating comprises a chromium phosphate coating and a chromium/chromic/chromate phosphate coating, characterised by applyign to said protective coating a polymerisable cationic organic material in an aqueous medium by precipitation or deposition in the presence of polyvalent metal ions and polymerising the material by heating to form a polymer coating over said protective coating.