This International Standard reviews published methods for revealing pores (see ISO 2080) and discontinuities
in coatings of aluminium, anodized aluminium, brass, cadmium, chromium, cobalt, copper, gold, indium, lead,
nickel, nickel-boron, nickel-cobalt, nickel-iron, nickel-phosphorus, palladium, platinum, vitreous or porcelain
enamel, rhodium, silver, tin, tin-lead, tin-nickel, tin-zinc, zinc and chromate or phosphate conversion coatings
(including associated organic films) on aluminium, beryllium-copper, brass, copper, iron, NiFeCo alloys,
magnesium, nickel, nickel-boron, nickel-phosphorus, phosphor-bronze, silver, steel, tin-nickel and zinc alloy
basis metal.
The tests summarized in this International Standard are designed to react with the substrate when exposed,
by a discontinuity, in such a way as to form an observable reaction product.
NOTE 1 Pores are usually perpendicular to the coating surface but may be inclined to the coating surface. They are
frequently cylindrical in shape but may also assume a twisted shape (see Annex C).
NOTE 2 Porosity may vary in size from the submicroscopic, invisible using a light microscope, to the microscopic,
visible from × 10 to × 1 000, to the macroscopic, visible to the naked eye.
NOTE 3 Porosity may be visibly indicated by discolouration of the coated surface.
NOTE 4 Porosity in a coating is not always detrimental. In microdiscontinuous chromium, for example, porosity or
microcracking is beneficial and tests are conducted to indicate the pores.
NOTE 5 Results obtained from porosity tests, expressed in terms such as pores per square centimeter, are relative
values associated with the specific test method used and the magnification used during examination. Annex B gives
typical report criteria.
Die Norm gibt eine Übersicht über jene Prüfverfahren, welche zum Nachweis der Porosität von einer Vielzahl von metallischen, anorganischen und organischen Überzügen geeignet sind. Diesen Prüfungen liegt das gemeinsame Prinzip zugrunde, daß eine Unregelmäßigkeit im Überzug eine Reaktion zwischen dem Grundwerkstoff und einer Prüfsubstanz zuläßt - das Reaktionsprodukt wird nachgewiesen.