1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
2、from, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions. Copyright 2013 SAE International All rights reserved. No part of this p
3、ublication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-497
4、0 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/AMS2471H AEROSPACE MATERIAL SPECIFICATION AMS2471 REV. H Issued 1958-08 Reaffirme
5、d 2007-04 Revised 2014-02 Superseding AMS2471G Anodic Treatment of Aluminum Alloys Sulfuric Acid Process, Undyed Coating RATIONALE AMS2471H results from a Five Year Review and update of this specification. NOTICE ORDERING INFORMATION: The following information shall be provided to the processor by t
6、he purchaser. 1. Purchase order shall specify not less than the following: AMS2471H Basis metal to be anodized Special features, geometry or processing present on parts that requires special attention by the processor Optional: Alternative sealing solution (3.1.2) Quantity of pieces to be anodized 2
7、. Parts manufacturing operations such as heat treating, forming, joining and media finishing can affect the condition of the substrate and adversely affect the finished part. The sequencing of these types of operations should be specified by the cognizant engineering organization or purchaser and is
8、 not controlled by this specification. 1. SCOPE 1.1 Purpose This specification establishes the requirements for undyed anodic coatings on aluminum alloys. 1.2 Application This process has been used typically to increase corrosion resistance and to provide surfaces that will promote adherence of pain
9、t and other organic finishes, but usage is not limited to such applications. 1.2.1 AMS2472 should be specified for coatings colored by dyeing. This process is not suitable for parts that contain joints or recesses in which the anodizing solution may be retained. SAE INTERNATIONAL AMS2471H Page 2 of
10、7 1.3 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 t
11、he 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. 2. APPLICABLE DOCUMENTS The issue of the following documents in effect on the date of the purchase order forms
12、 a part of this specification to the extent specified herein. The supplier may work to a subsequent revision of a document unless a specific document issue is specified. When the referenced document has been cancelled and no superseding document has been specified, the last published issue of that d
13、ocument shall apply. 2.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org AMS2472 Anodic Treatment of Aluminum Alloys, Sulfuric Acid Process, Dyed Coating AMS2473
14、 Chemical Film Treatment for Aluminum Alloys, General Purpose Coating AMS4037 Aluminum Alloy, Sheet and Plate, 4.4Cu - 1.5Mg - 0.60Mn, (2024; -T3 Flat Sheet, -T351 Plate), Solution Heat Treated 2.2 ASTM Publications Available from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Consho
15、hocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org ASTM B 117 Operating Salt Spray (Fog) Apparatus ASTM B 137 Measurement of Coating Mass Per Unit Area on Anodically Coated Aluminum 3. TECHNICAL REQUIREMENTS 3.1 Solutions 3.1.1 Electrolyte shall be an aqueous solution of sulfuric acid of suitabl
16、e concentration maintained within 2 F (1 C) of the temperature approved in 4.4.3. See 8.2.11. 3.1.2 Sealer Unless otherwise approved, the sealer shall be an aqueous solution of sodium dichromate or potassium dichromate See 8.2.9. 3.2 Preparation 3.2.1 Cleaning and Deoxidation Parts shall have clean
17、surfaces, free from water break, prior to immersion in the anodizing bath. Etching to achieve metal removal is required for cast surfaces. 3.2.1.1 Cleaning materials or products used for surface preparation containing iron, such as steel wool, iron oxide rouge, or steel wire, which may become embedd
18、ed in the metal and accelerate subsequent corrosion, are prohibited. SAE INTERNATIONAL AMS2471H Page 3 of 7 3.2.2 Masking Areas where anodizing is prohibited shall be masked. 3.2.3 Tight electrical contact shall be maintained during the anodic treatment to prevent contact arcing (burning) of parts,
19、but small irregularities of coating at points of electrical contact are acceptable. For parts that are to be anodized all over, locations shall be acceptable to the cognizant engineering organization. For parts that are not to be anodized all over, locations shall be in areas on which coating is not
20、 required. 3.3 Procedure 3.3.1 Anodizing 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
21、 be maintained within 2 amperes per square foot (21.5 A/m2) 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
22、, parts shall be rinsed in clean water at ambient temperature. 3.3.2 Sealing Parts shall be immersed in the sealer solution (8.2.9) for a suitable time (8.2.10), then rinsed. The rinse shall be thorough, but slight staining resulting from the sealant solution is acceptable. Rinsing is not required i
23、f deionized water is used for sealing. 3.4 Properties Coated parts shall conform to the following requirements: 3.4.1 Coating Weight The unsealed coating weight (4.3.3.2), determined in accordance with ASTM B 137, shall be not less than 600 mg/square foot (6.5 g/m2). 3.4.1.1 If small parts, such as
24、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. 3.4.2 Corrosion Resistance Panels in accordance with 4.3.3.3 s
25、hall 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 six degrees from vertical. The five test panels shall show not more than a total of 15 isolated pi
26、ts, none larger than 1/32 inch (0.8 mm) in diameter, in a total of 150 sq inches (968 cm2) of test area. Areas within 1/16 inch (1.6 mm) of identification markings or of an edge, or at electrode contact marks, shall not be included. Individual test specimens shall show no more than five isolated pit
27、s none larger than 1/32 (0.8 mm)inch in a total of 30 sq. inches (194 cm2). See Notes, 8.4.1.for pit morphology definitions. 3.5 Touch Up Damaged areas of parts on which the anodic coating has been scratched or damaged superficially may be coated using AMS2473 or another method acceptable to the cog
28、nizant engineering organization. Touch-up, unless otherwise specified, shall not exceed 0.5 inch (13 mm) in its longest dimension, except that scratches that are essentially one dimensional (less than 0.03 inches (0.8 mm) wide) may be reworked. The total reworked area shall not exceed 5% of the tota
29、l surface area. SAE INTERNATIONAL AMS2471H Page 4 of 7 3.6 Quality Anodic coating, as received by purchaser, shall be continuous, smooth, adherent, and uniform in appearance, and shall be free from powdery areas, loose films, discontinuities such as breaks or scratches (except at contact points), or
30、 other damage or imperfections detrimental to usage of the coating. Differences in the anodic coating appearance on castings or wrought components due to welds, or cast vs. machined surface textures, or macro grain size and other inherent metallurgical artifacts shall not be cause for rejection of t
31、he anodic coating. See 8.6. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for Inspection The coating processor shall supply all samples for processors tests and shall be responsible for the performance of all required tests. Parts, if required for tests, shall be supplied by purchaser. Processo
32、r may utilize his own or any other inspection facilities or services acceptable to purchaser. The cognizant engineering organization reserves the right to sample and to perform any confirmatory testing deemed necessary to ensure that processing conforms to specified requirements. 4.2 Classification
33、of Tests 4.2.1 Acceptance Tests Quality (3.6) is an acceptance test and shall be performed on parts, or samples representing parts when permitted, from each lot. 4.2.2 Periodic Tests Coating weight (3.4.1) and corrosion resistance (3.4.2) are periodic tests and shall be performed at least monthly in
34、 any month that parts are processed unless frequency of testing is specified by the cognizant engineering organization. Tests of cleaning and processing solutions are periodic tests and shall be performed at a frequency established by the processor unless frequency of testing is specified by the cog
35、nizant engineering organization. See 8.3 and 4.4.3. 4.2.3 Preproduction Tests All property verification tests (See 3.4) are preproduction tests and shall be performed prior to or on the initial shipment of processed parts to a purchaser and when the cognizant engineering organization requires confir
36、matory testing. 4.3 Sampling for Testing 4.3.1 Acceptance Tests Acceptance test samples shall be randomly selected from all parts in the lot. A lot shall be all parts of the same part number, processed in a continuous series of operations (3.3.1 and 3.3.2), in not longer than 24 consecutive hours, a
37、nd presented for processors inspection at one time. Unless the cognizant engineering organization provides a sampling plan, the minimum number of samples shall be as shown in Table 1. TABLE 1 - SAMPLING FOR ACCEPTANCE TESTING Number of Parts in Lot Quality Up to 7 All 8 to 15 7 16 to 40 10 41 to 110
38、 15 111 to 300 25 301 to 500 35 Over 500 50 SAE INTERNATIONAL AMS2471H Page 5 of 7 4.3.2 Periodic and Preproduction Tests Sample quantities shall be three for coating weight and five for corrosion resistance unless otherwise specified by the cognizant engineering organization. 4.3.3 Sample Configura
39、tion 4.3.3.1 Separate test specimens may be used under any one of the following circumstances: The parts are of such configuration or size as to be not readily adaptable to specified tests, nondestructive testing is not practical on actual parts, or it is not economically acceptable to perform destr
40、uctive tests on actual parts. Acceptance test specimens shall be distributed within the lot, cleaned, anodized, and sealed with the parts represented. 4.3.3.2 Coating weight shall be determined on representative parts when size and shape permit accurate determination of surface area. If parts are of
41、 such size and shape that surface area cannot be determined readily, coating weight determinations shall be made on separate test panels 0.025 to 0.063 inch (0.64 to 1.60 mm) thick and not less than 3 inches (76 mm) square fabricated from 2024-T3 aluminum alloy in accordance with AMS4037. 4.3.3.3 Co
42、rrosion resistance test panels shall be 0.025 to 0.063 inch (0.64 to 1.60 mm) thick and not less than 3 10 inches (76 254 mm) in width and length fabricated from 2024-T3 aluminum alloy in accordance with AMS4037. 4.4 Approval 4.4.1 Processes, control factors, or preproduction sample part or test pan
43、el, or any combination thereof specified, shall be approved by the cognizant engineering organization before production parts are supplied. 4.4.2 If the processor makes a significant change to any material, process, or control factor from that which was used for process approval, all preproduction t
44、ests shall be performed and the results submitted to the cognizant engineering organization for process reapproval unless the change is approved by the cognizant engineering organization. A significant change is one which, in the judgment of the cognizant engineering organization, could affect the p
45、roperties or performance of the parts. 4.4.3 Control factors for anodizing shall include, but not be limited to, the following: Cleaning procedure, including the compositions and temperatures of the baths used Deoxidation process Anodizing bath composition (including impurity limits), temperature, a
46、nd agitation method Rate of voltage rise, anodizing voltage, and time of anodizing Sealing solution composition (including impurity limits), temperature, and pH Purity of water used for sealing and rinsing Stripping procedure, when applicable Periodic test plan for cleaning and processing solutions.
47、 See 8.3. 4.5 Reports The processor of coated parts shall furnish with each shipment a report stating that the parts have been processed and tested in accordance with specified requirements and that they conform to the acceptance test requirements. This report shall include the purchase order number
48、, lot number, AMS2471H, part number, and quantity. 4.6 Resampling and Retesting 4.6.1 If any lot acceptance test fails to meet specified requirements, parts in that lot may be stripped, pretreated, coated, post-treated as defined herein and retested. Alternatively, all parts in the lot may be inspec
49、ted for the nonconforming attribute, and the nonconforming parts may be stripped, pretreated, recoated, post-treated as defined herein, and retested. After any stripping and recoating, parts shall meet the dimensional requirements of the drawing. SAE INTERNATIONAL AMS2471H Page 6 of 7 4.6.1.1 When stripping is performed, the method shall be acceptable to the cognizant engineering organization and shall not roughen, pit
