METHOD FOR CHEMICAL CONVERSION TREATMENT OF THE SURFACE OF ALUMINUM MATERIAL AND ALUMINUM MATERIAL

摘要

Disclosed is a method for chemical conversion treatment of the surface of an aluminum material comprising aluminum or an aluminum alloy. The method comprises performing a chemical conversion treatment of the surface of the aluminum material with a treatment solution for 1 to 5 minutes to form a coating film having excellent corrosion resistance and coating film adhesion property, wherein the treatment solution contains a trivalent chromium, and has a chromium nitrate content of 3 to 12 g/L in terms of Cr(NO3)3, a ammonium vanadate content of 0.5 to 7 g/L in terms of NH4VO3, a potassium fluorotitanate content of 0.5 to 3 g/L in terms of K2TiF6, a lithium fluoride content of 0.5 to 3 g/L in terms of LiF, a nitric acid content of 0.5 to 1.8 mL/L in terms of HNO3, and a liquid temperature of 40 to 50ºC. Also disclosed is an aluminum material having a coating film formed by the method.