SURFACE TREATMENT METHOD FOR ALUMINUM-BASED SUBSTRATE, AND SURFACE-TREATED SUBSTRATE

摘要

PROBLEM TO BE SOLVED: To provide a surface treatment method for an aluminum-based substrate, which forms a chemical conversion coating and a hydrophilic coating having superior corrosion resistance, hydrophilicity and antibromic property on the aluminum-based substrate; a surface-treated substrate by the method; and a heat exchanger. SOLUTION: The surface treatment method for the aluminum-based substrate comprises a step (1) of forming the chemical conversion coating on the surface of the aluminum-based substrate by reacting the surface with a chemical conversion agent including fluorine and a zirconium-containing compound, and/or fluorine and a titanium-containing compound; and a step (2) of forming a hydrophilic coating thereon by using a hydrophilic treatment agent. The chemical conversion coating is formed by an electrolytic treatment. COPYRIGHT: (C)2005,JPO&NCIPI