Реферат

This specification covers the requirements for porous oxide coatings deposited by electrolysis on aluminum and aluminum alloy parts. These coatings should have good appearance, abrasion resistance, electrical properties, and protection against corrosion and does not include nonporous barrier layer anodic coatings that are used for electrical capacitors. The basis metals for these coatings should be subjected to mechanical finishing operations, cleaning, and chemical or electrolytic pre-treatments to yield coatings with fine quality and appearance. Anodized parts should be sealed in water or aqueous chemical solutions except when otherwise specified. Each anodic coating should be continuous, smooth, adherent, uniform in appearance, and free of powdery areas (burns, loose films, stains, discolorations, and discontinuities.

Область применения

1.1 This specification covers requirements for electrolytically formed porous oxide coatings on aluminum and aluminum alloy parts in which appearance, abrasion resistance, electrical properties, and protection against corrosion are important. Nonporous, barrier layer anodic coatings used for electrical capacitors are not covered. Seven types of coatings as shown in Table 1 are provided. Definitions and typical examples of service conditions are provided in Appendix X1.

Note 1—It is recognized that uses exist in which modifications of the coatings covered by this specification may be required. In such cases the particular properties desired by the purchaser should be the subject of agreement between the purchaser and the manufacturer.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

TABLE 1 Anodic Coatings Descriptions

Note—Hard coatings may vary in thickness from 12 μm to more than 100 μm. If the thickness of Type A is not specified, it shall be 50 μm min. Type A coatings will not be sealed unless so specified.

TypeCoating (Industry) DescriptionMinimum Film Thickness (μm) AEngineering Hard Coat50 BArchitectural Class I18 CArchitectural Class II10 DAutomotive—Exterior 8 EInterior—Moderate Abrasion 5.0 FInterior—Limited Abrasion 3 GChromic Acid 1