CEN/TC 132/WG 15 - Aluminium anodisation

This document specifies a method for the determination of the surface abrasion resistance of anodic oxidation coatings produced by sulfuric acid anodizing of aluminium and its alloys. It is mainly intended for the evaluation of external architectural coatings. It is a production control method that relies to a large extent on operator experience and instruction.

ISO 7599:2018 specifies a method for specifying decorative and protective anodic oxidation coatings on aluminium (including aluminium-based alloys). It defines the characteristic properties of anodic oxidation coatings, lists methods of test for checking the characteristic properties, provides minimum performance requirements, and gives information on the grades of aluminium suitable for anodizing and the importance of pretreatment to ensure the required appearance or texture of the finished work.
It is not applicable to
a)    non-porous anodic oxidation coatings of the barrier layer type,
b)    anodic oxidation coatings produced by chromic acid or phosphoric acid anodizing,
c)    anodic oxidation coatings intended merely to prepare the substrate for subsequent application of organic coatings or for the electrodeposition of metals, and
d)    hard anodic oxidation coatings used mainly for engineering purposes, for which abrasion and wear resistance are the primary characteristics (see ISO 10074).

ISO 2931:2017 specifies a method for assessing the quality of sealed anodic oxidation coatings on aluminium and its alloys by measurement of the admittance.
The method is applicable to anodic oxidation coatings sealed in an aqueous medium.
NOTE 1    Results obtained from anodic oxidation coatings sealed by different methods, e.g. hydrothermal sealing and cold sealing, are not necessarily comparable.
NOTE 2    Results obtained from anodic oxidation coatings on alloys containing more than 2 % silicon or 5 % manganese or 3 % magnesium are not comparable with results obtained from anodic oxidation coatings on more dilute alloys.
The method is suitable for use as a production-control test and as an acceptance test where there is agreement between the anodizer and the customer.
Any type of anodized component can be tested by the method described, provided that there is a sufficient area (a circle of diameter about 20 mm) and that the film thickness is greater than 3 µm.

ISO 2143 specifies a method of estimating the loss of absorptive power of anodic oxidation coatings that have undergone a sealing treatment, by dye absorption after acid pretreatment.
The method is suitable for use as a production control method and can be applicable to anodic oxidation coatings which may be subjected to weathering or aggressive environments, or where resistance to staining is important.
The method is not applicable to those coatings that
a)    are formed on alloys containing more than 2 % copper or 4 % silicon,
b)    are sealed by the dichromate process,
c)    have been given supplementary processing, e.g. oiling, waxing or lacquering,
d)    are coloured in deep shades, and
e)    are less than 3 μm thickness.
The method is less appropriate where nickel or cobalt salts, or organic additives, have been added to baths used for hydrothermal sealing.

ISO 6719:2010 specifies a method of measuring the total and diffuse luminous reflectance characteristics of aluminium surfaces, using integrating-sphere instruments.
The method specifed is also applicable to the measurement of specular reflectance (principal gloss value), specularity and diffuseness.
The method is unsuitable for use with lighting reflectors.

ISO 7759:2010 specifies a method for the measurement of the reflectance characteristics of high-gloss anodized aluminium surfaces.
The method described is also suitable for the measurement of the reflectance characteristics of other high-gloss metal surfaces.
The method is not suitable for diffuse-finish metal surfaces and does not measure colour.

ISO 2128:2010 specifies a non-destructive method for determining the thickness of anodic oxidation coatings on aluminium and its alloys using a split-beam microscope.
The method is applicable, in most industrial cases, to anodic oxidation coatings above 10 μm, or above 5 μm when the surface is smooth.
The use of the method specified is limited by the need for the two luminous lines described in Clause 3 to be visible and distinctly separated, i.e. not in the case of opaque or dark-coloured coatings.

ISO 2106:2011 specifies a gravimetric method for determining the mass per unit area (surface density) of anodic oxidation coatings on aluminium and its alloys.
The method is applicable to all oxidation coatings formed by anodizing aluminium and its alloys, either cast or wrought, and is suitable for most aluminium alloys, except those in which the copper content is greater than 6 %.

ISO 2376:2010 specifies test methods for the determination of the electric breakdown potential of anodic oxidation coatings on aluminium and its alloys, on flat or near-flat surfaces and on round wire. The methods are applicable to anodic oxidation coatings used primarily as electrical insulators.
The methods are not applicable to coatings in the vicinity of cut edges, the edges of holes, or sharp changes of angle on, for example, extruded shapes.

ISO 3211:2010 specifies an empirical method for assessing the resistance of anodic oxidation coatings to cracking by deformation.
The method is applicable particularly to sheet material with anodic oxidation coatings of thickness less than 5 µm, and is useful for development purposes.

ISO 8994:2011 specifies a grid rating system that provides a means of defining levels of performance of anodic oxidation coatings on aluminium and its alloys that have been subjected to corrosion tests.
This rating system is applicable to pitting corrosion resulting from
accelerated tests,
exposure to corrosive environments, and
practical service tests.
ISO 8994:2011 takes into account only pitting corrosion of the basis metal resulting from penetration of the protective anodic oxidation coating.

ISO 8993:2010 specifies a chart rating system based on standard charts that provides a means of defining levels of performance of anodic oxidation coatings on aluminium and its alloys that have been subjected to corrosion tests.
This rating system is applicable to pitting corrosion resulting from
accelerated tests,
exposure to corrosive environments, and
practical service tests.
ISO 8993:2010 takes into account only pitting corrosion resulting from penetration of the protective anodic oxidation coating.

ISO 2085:2010 specifies a method for checking the continuity of thin anodic oxidation coatings on aluminium and its alloys by a copper sulfate contact test.
The use of this method is limited to anodic oxidation coatings of thickness less than 5 μm, or coatings that have been deformed.

ISO 6581:2010 specifies a comparative method for the determination of the fastness of coloured anodic oxidation coatings to ultraviolet (UV) light and heat.
The method is not suitable for testing coloured anodic oxidation coatings that are heat sensitive.

ISO 8251:2011 specifies the following three test methods: a) abrasive-wheel-wear test method, determining the wear resistance and the wear index of anodic oxidation coatings on flat specimens of aluminium and its alloys; b) abrasive jet test method, comparing the resistance to abrasion of anodic oxidation coatings on aluminium and its alloys with that of a standard specimen or, alternatively, a reference specimen, by use of a jet of abrasive particles; c) falling sand abrasion method, determining the abrasion resistance with falling sand applied to thin anodic oxidation coatings.
The use of these methods for coatings produced by hard anodizing is described in ISO 10074.

ISO 7668:2010 specifies methods for the measurement of specular reflectance and specular gloss of flat samples of anodized aluminium using geometries of 20° (Method A), 45° (Method B), 60° (Method C) and 85° (Method D); and of specular reflectance by an additional 45° method (Method E) employing a narrow acceptance angle.
The methods described are intended mainly for use with clear anodized surfaces. They can be used with colour-anodized aluminium, but only with similar colours.

ISO 10215:2010 specifies a visual method for determining the image clarity of anodic oxidation coatings on aluminium and aluminium alloys, using a chart scale and a lightness scale, which are defined. The method can be applied only to flat surfaces that can reflect the image of the chart scale pattern.

ISO 7599:2010 lays down a method for specifying decorative and protective anodic oxidation coatings on aluminium (including aluminium-based alloys). It defines the characteristic properties of anodic oxidation coatings, lists methods of test for checking the characteristic properties, provides minimum performance requirements, and gives information on the grades of aluminium suitable for anodizing and the importance of pretreatment to ensure the required appearance or texture of the finished work.
It is not applicable to non-porous oxidation coatings of the barrier layer type, oxidation coatings produced by chromic acid or phosphoric acid anodizing, oxidation coatings intended merely to prepare the substrate for subsequent application of organic coatings or electrodeposition of metals, or hard anodic oxidation coatings used mainly for engineering purposes, for which abrasion and wear resistance are the primary characteristics (see ISO 10074).

ISO 2931:2010 specifies a method for assessing the quality of sealed anodic oxidation coatings on aluminium and its alloys by measurement of the admittance.
The method is applicable to anodic oxidation coatings sealed in an aqueous medium.
The method is suitable for use as a production-control test and as an acceptance test where there is agreement between the supplier and the customer.
Any type of anodized component can be tested by the method described, provided that there is a sufficient area (a circle of diameter about 20 mm ) and that the film thickness is greater than 3 µm.

ISO 3210:2010 specifies methods of assessing the quality of sealed anodic oxidation coatings on aluminium and its alloys by measurement of the loss of mass after immersion in phosphoric acid/chromic acid solution.
ISO 3210:2010 consists of the following two methods.
Method 1: assessment of quality of sealed anodic oxidation coatings by measurement of the loss of mass after immersion in phosphoric acid/chromic acid solution, without prior acid treatment.
Method 2: assessment of quality of sealed anodic oxidation coatings by measurement of the loss of mass after immersion in phosphoric acid/chromic acid solution with prior acid treatment.
Method 1 is applicable to anodic oxidation coatings intended for decorative or protective purposes or where resistance to staining is important.
Method 2 is applicable to anodic oxidation coatings intended for architectural purposes. For less severe applications, Method 1 may be more suitable.
The methods are not applicable to the following:
hard-type anodic oxidation coatings which normally are not sealed;
anodic oxidation coatings that have been sealed only in dichromate solutions;
anodic oxidation coatings produced in chromic acid solutions;
anodic oxidation coatings that have undergone a treatment to render them hydrophobic.

ISO 2143:2010 specifies a method of estimating the loss of absorptive power of anodic oxidation coatings that have undergone a sealing treatment, by dye absorption after acid pretreatment.
The method is suitable for use as a production control method and is applicable to anodic oxidation coatings which may be subjected to weathering or aggressive environments, or where resistance to staining is important.
The method is not applicable to those coatings that: a) are formed on alloys containing more than 2 % copper or 4 % silicon; b) are sealed by the dichromate process; c) have been given supplementary processing, e.g. oiling, waxing or lacquering; d) are coloured in deep shades; e) are less than 3 μm thick.
The method is less appropriate where nickel or cobalt salts, or organic additives, have been added to the sealing bath.

This part of this European Standard specifies a grid rating system that provides a means of defining levels of performance of anodic oxidation coatings on aluminium and its alloys that have been subjected to corrosion tests. This rating system is applicable to pitting corrosion resulting from - accelerated tests; - exposure to corrosive environments; - practical service tests.

This part of this European Standard specifies a gravimetric method for determining the mass per unit area (surface density) of anodic oxidation coatings on aluminium and its alloys. The method is applicable to all oxide coatings formed by anodizing aluminium and its alloys, either cast or wrought, and is suitable for most aluminium alloys except those in which the copper content is greater than 6 %.

This part of this European Standard specifies a method of test for comparing the resistance to abrasion of anodic oxidation coatings on aluminium and its alloys with that of a standard specimen or, alternatively, a reference specimen, by the use of a jet of abrasive particles. The mean specific abrasion resistance of an anodic oxidation coating may be determined by the method described.

This part of this European Standard specifies a method of test for determining the wear resistance and the wear index of anodic oxidation coatings on flat specimens of aluminium and its alloys by means of an abrasive wheel wear test apparatus.

This part of this European Standard specifies methods for the measurement of specular reflectance and specular gloss of flat samples of anodized aluminium using geometries of 20° (method A), 45° (method B), 60° (method C) and 85° (method D), and of specular reflectance by an additional 45° method (method E) employing a narrow acceptance angle. The methods described are intended mainly for use with clear anodized surfaces. They can be used with colour-anodized aluminium, but only with similar colours.

This Part of this European Standard specifies a method of measuring the total and diffuse luminous reflectance characteristics of aluminium surfaces, using integrating-sphere instruments. The method described is applicable also to the measurement of specular reflectance (principal gloss value), specularity, and diffuseness. The method is unsuitable for use with lighting reflectors.

This part of this European Standard specifies a method for the measurement of the reflectance characteristics of high-gloss anodized aluminium surfaces. The method described is also suitable for the measurement of the reflectance characteristics of other high-gloss metal surfaces. The method is not suitable for diffuse-finish metal surfaces and does not measure colour.

This part of this European Standard specifies an empirical method for assessing the resistance of anodic oxidation coatings to cracking by deformation. The method is applicable particularly to sheet material with anodic oxidation coatings of thickness less than 5 micrometres, and is useful for development purposes.

This Part of this European Standard specifies a non-destructive method of determining the thickness of anodic oxidation coatings on aluminium and its alloys using a split-beam microscope. The method is applicable, in most industrial cases, to anodic oxidation coatings above 10 um, or above 5 um when the surface is smooth.

This part of this European Standard specifies a method of checking the continuity of thin anodic oxidation coatings on aluminium and its alloys by a copper sulfate contact test. The use of this method is limited to anodic oxidation coatings of less than 5 micrometres thickness, or coatings that have been deformed. Note: The method described enables a rapid check to be made for the continuity of a thin coating of aluminium oxide on aluminium and its alloys.

This part of this European Standard specifies a visual method for determining the image clarity of anodic oxidation coatings on aluminium and aluminium alloys using a chart scale and a lightness scale, which are defined. The method can be applied only to flat surfaces which can reflect the image of the chart scale pattern.

This part of this European Standard specifies methods of test for the determination of the electrical breakdown potential of anodic oxidation coatings on aluminium and its alloys on flat or near-flat surfaces and on round wire. The methods are applicable to anodic oxidation coatings used primarily as electrical insulators. The methods are not applicable to coatings in the vicinity of cut edges, the edges of holes, or sharp changes of angle on, for example, extruded shapes. Note 1: The methods described do not give satisfactory results for unsealed coatings. Note 2: Electrical breakdown potential is affected by relative humidity.

This Part of this European standard specifies a chart rating system based on standard charts that provides a means of defining levels of performance of anodic oxidation coatings on aliminium and its alloys that have been subjected to corrosion tests. This rating system is applicable to pitting corrosion resulting from - accelerated tests; - exposure to corrosive environments; - practical service tests.

This part of this European standard specifies a comparative method for the determination of the fastness of coloured anodic oxidation coatings to ultra-violet light and heat. The method is not suitable for testing coloured anodic oxidation coatings that are heat sensitive. Note: Dark coloured test pieces will normally reach the highest temperatures.

This Part of this European Standard describes a method for specifying decorative and protective anodic oxidation coatings on aluminium. It is applicable to the specification of coatings mainly of aluminium oxide, which are formed on aluminium by an electrolytic oxidation process in which the aluminium acts as the anode.

This part of this European Standard specifies a method of estimating the loss of absorptive power of anodic oxidation coatings that have undergone a sealing treatment, by dye absorption after acid pretreatment. The method is suitable for use as a production control method and is applicable to anodic oxidation coatings which may be subjected to weathering or aggressive environments or where resistance to staining is important.

This part of this European Standard specifies a method of assessing the quality of sealed anodic oxidation coatings on aluminium and its alloys by measurement of the loss of mass after immersion in phosphoric acid/chromic acid solution without prior acid treatment. A related standard (EN 12373-7) describes the same method used with prior acid treatment.

This Part of this European Standard specifies a method for assessing the quality of sealed anodic oxidation coatings on aluminium and its alloys by measurement of the admittance. The method is applicable to anodic oxidation coatings sealed in an aqueous medium. The method is suitable for use as a production control test and as an acceptance test where there is agreement between the supplier and the purchaser.

This part of this European Standard specifies a method of assessing the quality of sealed anodic oxidation coatings on aluminium and its alloys by measurement of the loss of mass after immersion in phosphoric acid/chromic acid solution with prior acid treatment. A related standard (EN 12373-6) describes the same method used without prior acid treatment.