SURFACE TREATED AL OR AL ALLOY MATERIAL EXCELLENT IN CORROSION RESISTANCE AFTER COATING

摘要

PURPOSE: To obtain a surface treated Al base metallic material excellent in corrosion resistance after coating by applying an Mn series alloy plating layer contg. specified amounts of metals among Zn, Fe, Ni and Co. ;CONSTITUTION: The surface of an Al or Al allay material is applied with an Mn series allay plating layer contg., by weight, 1 to 50% of one or more kinds of metals among Zn, Fe, Ni and Co and the balance Mn by 0.1 to 3g/m². In this way, excellent corrosion resistance after coating can be obtd. This is considered that, because Mn ions eluted from the plating layer at the time of phosphating are taken into a phosphate film, the alkali resistance of the phosphate film improves. Furthermore, as for the metals such as Zn in the plating layer, by weakening their solubility at the time of the phosphating of the plating layer, a uniform and fine phosphate film can be formed, and especially, as for Fe, Ni and Co, by allowing their eluted ions to be taken into the phosphate film, the effect similar to that by Mn can be expected.;COPYRIGHT: (C)1993,JPO&Japio