SAE AMS 2472E pdf download

SAE AMS 2472E pdf download.Anodic Treatment of Aluminum Alloys Sulfuric Acid Process, Dyed Coating.
1.1 Purpose:
This specification establishes the engineering requirements for producing dyed anodic coatings on aluminum alloys and the properties of such coatings.
1 .2 Application:
This process has been used typically to increase Corrosion resistance and to produce colored surfaces on aluminum alloy parts, but usage is not limited to such applications.
1.2.1 AMS 2470 or AMS 2471 should be specified for coatings to be used as a base for paint or other organic finishes. This process is not suitable for parts which contain joints or recesses in which the anodizing solutions may be retained.
1 .3 Classification:
This specification covers two types of coating classified as follows:
Class 1 Coatings for Identification
Class 2 Coatings for Decorative Purposes
When no class is specified, Class 1 shall be supplied.
1.4 Safety – Hazardous Materials:
While the materials, methods, applications, and processes described or referenced in this specification may involve the use of hazardous materials, this specification does not address the hazards which may be involved in such use. It is the sole responsibility of the user to ensure familiarity with the safe and proper use of any hazardous materials and to take necessary precautionary measures to ensure the health and safety of all personnel involved.
3.2.3 Coating: The cleaned parts shall be made the anode(s) in the electrolyte contained in a chemical- resistant tank which may also serve as the cathode. The processing shall be adjusted to obtain the required weight and quality of the coatings. The anodizing current shall be maintained within ±2 amperes per square toot (±21.5 Aim2) of the nominal value. Alternatively, the anodizing current shall be ramped up over a five minute, or other preselected period, to the desired final voltage and maintained until the anodic coating reaches the desired thickness. After anodizing, parts shall be rinsed thoroughly in water at ambient temperature.
Dyeing: Prior to sealing, parts shall be dyed to the specified color by immersing in a appropriate dye solution. The temperature of the solution and the time of immersion shall be as necessary to produce the specified color. Parts shall then be rinsed in clean water at ambient temperature.
32.5 Sealin9: Parts shall be immersed in the sealer solution for a suitable time (See 8.2.11). After sealing, the parts shall be thoroughly rinsed in clean water at ambient temperature, rinsed in clean hot water, and dried.
3.3 Properties:
Coated parts shall conform to the following requirements:
3.3.1 Coating Weight: The coating weight (See 4.3.2.1), determined in accordance with ASTM B 137, shall be not less than 600 mg/square foot (6.5 g/m2) when AMS 2472, Class 1, is specified, and not less than 2500 mg/square toot (27 g/m2) when AMS 2472, Class 2. Is specified, except for wrought aluminum alloys of the 2000 series where copper is the major alloying element, and for aluminum casting alloys with a nominal copper content of 1% or higher, the coating weight when AMS 2472, Class 2. is specified shall be not less than 1400 mg/square foot (15 g/m2).
3.3.1.1 If small parts, such as rivets or machine screws, are anodized in bulk in a container, the specified coating weight shall apply to not less than 75% of the parts treated together, determined by random sampling, but in no case shall any part show uncoated areas.
3.3.2 Corrosion Resistance: Panels (See 4.3.2.2) shall meet the following requirements, determined after exposure for not less than 336 hours to salt spray corrosion test in accordance with ASTM B 117. except that significant surface shall be inclined 6 degrees from vertical. Areas within 1/16 inch (1.6 mm) of identification markings or of an edge or at electrode contact marks shall not be induded.
Fifteen scattered spots or pits, none larger than 1/32 inch (0.8 mm) diameter, on a total of 150 square inches (968 cm2) of test area from five or more test pieces.
Five scattered spots or pits. none larger than 1/32 inch (0.8 mm) diameter, on any 30 square inches (194 cm) attest area from one or more test pieces.