ISO 7599 pdf download – Anodizing of aluminium and itsalloys — Method for specifyingdecorative and protective anodicoxidation coatings on aluminium.
The abrasive-wheel wear test is the preferred method but is only suitable for flat specimens; the abrasive jet test can be used for specimens that are not flat.
NOTE Measurement of abrasion resistance of the surface of an anodic oxidation coating can give important guidance on the performance In external architectural applications. In particular, coatings which are likely to show chalking on external exposure an have a lower than normal abrasion resistance In this regard, a coating with a wear index of greater than 1,4, when measured by the abrasive-wheel wear test method given in ISO 8251 can perform unsatisfactorily.
11 ResIstance to cracking by deformation
If required by the customer, the resistance to cracking by deformation of the anodic oxidation coating shall be tested by the method specified In Iso 3211. The performance requirements shall be agreed between the anodizer and the customer.
12 Fastness to light and ultraviolet radiation
12.1 General
For evaluating colour fastness for exterior applications, only outdoor exposure under conditions comparable to actual service use is satisfactory. Accelerated testing is only suitable as a production control test of coloured anodic oxidation coatings where the Fastness of the specific colouring system has already been established by outdoor exposure tests.
If required by the customer, the test method or methods to be used and the performance requirements shall be specified by the customer to the anodizer.
The light fastness of colour anodized alumInium depends upon the method of colouring and the type of colouring material used, and — particularly in the case of dyed anodized aluminium — only a limited range of coloured finishes are suitable for any particular application. Advice from the anodizer should be sought.
12.2 Fastness to light
An accelerated method of testing the light fastness of coloured anodic oxidation coatings Is specified in ISO 2135. The performance of colour anodized aluminium, when tested by this method, shall be specified by the customer, if necessary in consultation with the .snodizer.
12.3 Fastness to ultraviolet radiation
A method ol testing the Iastness to ultr.wiolet radiation 01 coloured anodic oxidation coatings is specified In ISO 6581. ThIs isa relatively severe test in comparison with other tests for Fastness to light and colour changes take place with many colour anodized finishes in very short exposure times. The method is particularly suitable as a production control test for assessing the fastness to light of the extremely llght’reslstant anodlc oxidation coatings used In architecture.
The customer shall specify the performance requirement, if necessary in consultation with the anodizer.
13 Light reflection properties
13.1 General
If required by the customer, the light reflection properties of anodic oxidation coating may be carried out as Follows. The test method and performance requirements shall be agreed between the anodizer and the customer.
A.1 General
Most aluminium, in any of its forms, can be anodized (see A.4). but the results differ widely in appearance, colour, maximum coating thickness, reflectivity. abrasion resistance, corrosion resistance and electric breakdown potential. The protective value of the coating is excellent on much aluminium produced for general engineering purposes, but for uniformity of appearance or other special effects (for example, bright finishes), special grades of aluminium have been developed where close control of chemical composition and metallurgical practices is combined with special production procedures to provide high standards of surface finish and a guaranteed response to anodizing. These grades cannot readily be classified because companies have developed their range of products to meet the requirements ol particular industries or customers and there is no clear dividing line between the various categories.
The grades identified in A2, A,3 and A.4 are given for general guidance and are based on the end-use of the aluminium. The anodizer should be aware of the end-use and it is stressed that, for this reason, there should be close cooperation between the supplier of the aluminium, the customer and the anodizer.
A.2 Architectural and decorative quality
Semi-finished products of this grade will have a good appearance after anodizing.
Some variations in appearance and colour on anodized aluminium surfaces can be expected between different batches of the same material and between different forms of the same material. It is sometimes possible to observe on close inspection, or from certain viewing angles, variations In brightness, banding, streaking and other visual defects. These do not affect in any way the quality of the coating. The extent to which such defects can be accepted should be specified by the customer (see A and Annex B).
ISO 7599 pdf download – Anodizing of aluminium and itsalloys — Method for specifyingdecorative and protective anodicoxidation coatings on aluminium
