2. Getting involved
3. Standards Committees
4. FNNE

DIN Standards Committee Nonferrous Metals

Overview

This standard specifies a method of checking the continuity of thin anodic oxidation coatings on aluminium and its alloys by a copper sulphate contact test. The use of this method is limited to thin anodic oxidation coatings of thickness less than 5 µm, or coatings that have been deformed. The method described enables a rapid check to be made for the continuity of thin anodic oxidation coatings on aluminium and its alloys. In cases of doubt regarding a visible fault on the surface of a coating, the use of the copper sulphate test makes it possible to verify whether this fault in the protective coating goes all the way down to the bare metal. The following principle is followed: Drops of the copper sulphate reagent are applied on surface areas of about 100 mm2, chosen at will on the test pieces, but avoiding the anodizing contact areas. If the test area includes points where the metal is bare or is poorly covered by the oxidation coating, chemical displacement of the copper takes place on the aluminium, accompanied by a release of gas. The drops of applied reagent can be examined immediately upon application, either with the naked eye or with a magnifying glass; gas is released almost instantaneously at points where the aluminium is bare. After the test, black and/or dark reddish spots can be seen everywhere where the coating is not continuous. The International/European Standard has been prepared under the leadership of ISO/TC 79/SC 2/WG 16 "Revisions for systematic reviewed TC 79/SC 2 ISO standards" (secretariat: JISC, Japan) in a parallel procedure with CEN/TC 132/WG 15 "Aluminium anodisation" (secretariat: BSI, United Kingdom). On the national level the responsible Working Committee is NA 066-01-09 AA "Anodisch oxidiertes Aluminium" ("Aluminium anodisation") of FNNE.

Responsible national committee

NA 066-01-09 AA - Surface treatment of aluminium  

Responsible european committee

CEN/TC 132 - Aluminium and aluminium alloys