WATER-BASED COMPOSITION FOR SURFACE TREATMENT TO ENHANCE CORROSION RESISTANCE AND PLASTIC FORMABILITY OF ALUMINUM-CONTAINING METAL MATERIAL AND TREATING LIQUID AND TREATING METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To form a dense chemical conversion film having excellent corrosion resistance of the raw film, adhesion property of the coating film and forging property on the surface of a metal material containing aluminum. ;SOLUTION: A water-based treating liquid is prepared from at least one kind of heavy metal oxyoacid compound containing Mo, W, Re and V atoms, phosphate compd. and fluoride in such a manner that the weight ratio of the heavy metal oxyoacid ion, phosphate ion and fluorine is (0.1 to 50):(1 to 100):(0.1 to 10). This liquid is brought into contact with the surface of an Al-contg. metal material for the surface treatment. Then the treated surface is washed with water and dried to form a chemical conversion film.;COPYRIGHT: (C)1997,JPO