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 ther
2、efrom, 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
3、publication 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: +1 724-776-49
4、70 (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/AMS2473H RATIONALE AMS2473H results from a Five Year Review and update of this s
5、pecification. NOTICE ORDERING INFORMATION: The following information shall be provided to the processor by the purchaser. 1) Purchase order shall specify not less than the following: AMS2473H Basis metal to be conversion coated Quantity of pieces to be conversion coated Special features, geometry or
6、 processing present on parts that requires special attention by the processor Optional: Specific color, if required Optional: Specific instructions or restrictions on coating material type, if specified 2) Parts manufacturing operations such as heat treating, forming, joining and media finishing can
7、 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 not controlled by this specification. AEROSPACE MATERIAL SPECIFICATION AMS2473 REV. H Issued 19
8、53-02 Reaffirmed 2007-07 Revised 2013-08 Superseding AMS2473G Chemical Film Treatment for Aluminum Alloys General Purpose Coating SAE INTERNATIONAL AMS2473H Page 2 of 6 1. SCOPE 1.1 Purpose This specification establishes the requirements for chemical-film (conversion) coatings on aluminum alloys. 1.
9、2 Application This process has been used typically for increasing the corrosion resistance of aluminum alloy parts, as a base for paint or other organic finishes, and for repair of abraded surfaces or discontinuous anodized coatings on aluminum alloy parts, but usage is not limited to such applicati
10、ons. AMS2477 is intended for applications that include electrical bonding requirements. 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 add
11、ress 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. 2. APPLICABLE DOCUMENTS
12、The issue of the following documents in effect on the date of the purchase order forms 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 cancel
13、led and no superseding document has been specified, the last published issue of that document 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. A
14、MS2477 Conversion Coating for Aluminum Alloys, Low Electrical Resistance 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, W
15、est Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org. ASTM B 117 Operating Salt Spray (Fog) Testing Apparatus ASTM D 3359 Measuring Adhesion by Tape Test 2.3 U.S. Government Publications Available from the Document Automation and Production Service (DAPS), Building 4/D, 700 Robbins Avenu
16、e, Philadelphia, PA 19111-5094, Tel: 215-697-6257, http:/assist.daps.dla.mil/quicksearch/. MIL-PRF-23377 Primer Coatings, Epoxy Polyamide, Chemical and Solvent Resistant MIL-PRF-85582 Primer Coatings, Epoxy, VOC Compliant, Chemical and Solvent Resistant FED-STD-141 Paint, Varnish, Lacquer and Relate
17、d Materials, Methods of Inspection, Sampling and Testing SAE INTERNATIONAL AMS2473H Page 3 of 6 3. TECHNICAL REQUIREMENTS 3.1 Processing solution shall be an aqueous solution of chemicals which will form an oxide, phosphate, silicate, or chromate coating meeting the requirements of 3.4. 3.1.1 Only p
18、rocesses that permit solution control by chemical analysis shall be used. 3.2 Preparation 3.3 Procedure Coating shall be applied using a solution in accordance with 3.1 for a time and at a temperature that will produce coatings meeting the requirements of 3.4, followed by rinsing and drying. If part
19、s are not to be coated all over, areas that are to be free of coating may be masked or the solution may be applied by brushing, swabbing, or spraying the surfaces to be coated. 3.4 Properties The coating shall conform to the following requirements: 3.4.1 Corrosion Resistance Specimens in accordance
20、with 4.3.2 shall show no evidence of corrosion beyond the limits specified below after exposure for 168 hours 1 to salt spray corrosion testing conducted in accordance with ASTM B 117 except that the significant surface shall be inclined approximately 6 degrees from the vertical. 3.4.1.1 No test pan
21、el shall show more than five isolated spots or pits, none larger than 0.03 inch (0.8 mm) in diameter, except those areas within 0.25 inch (6.4 mm) from identification markings and fixture contact marks remaining after processing. Areas within 0.25 inch (6.4 mm) from the edges, identification marking
22、s, and racking points shall be excluded. Loss of color shall not be cause for rejection. See 8.5. 3.4.1.2 No more than 15 isolated spots or pits, none larger than 0.03 inch (0.8 mm) in diameter on all five test panels, See 8.5. 3.4.2 Primer Adhesion Specimens in accordance with 4.3.2 shall be finish
23、ed with one coat of MIL-PRF-23377 or MIL-PRF-85582 epoxy primer to a dry film thickness of 0.0006 to 0.0009 inch (15 to 23 m). Coated panels shall be allowed to dry for not less than 72 hours and tested for adhesion in accordance with FED-STD-141, Method 6301 or ASTM D3359 Method A Wet. There shall
24、be no evidence of separation between primer and conversion coating or between conversion coating and substrate. 3.4.3 Color Coating shall be any distinctive color and/or iridescence that distinguishes coated from the uncoated surfaces. See 8.4. 3.5 Quality The coating, as received by purchaser, shal
25、l be continuous, adherent to basis metal, and visually free from powdery residue, pin holes, pits, and other imperfections detrimental to usage of the parts. Appearance shall be uniform although slight variations in color and/or iridescence are permissible. SAE INTERNATIONAL AMS2473H Page 4 of 6 4.
26、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. Purchaser and the cognizant engineeerin
27、g organization reserve the right to sample and to perform any confirmatory testing deemed necessary to ensure that processing conforms to specified requirements. 4.2 Classification of Tests 4.2.1 Acceptance Tests Color (3.4.3) and quality (3.5) are acceptance tests and shall be performed on parts fr
28、om each lot. 4.2.2 Periodic Tests Corrosion resistance (3.4.1) and primer adhesion (3.4.2) are periodic tests and shall be performed at least monthly unless frequency of testing is specified by the purchaser or cognizant engineering organization. Tests of cleaning and processing solutions are period
29、ic tests and shall be performed at a frequency established by the processor unless frequency of testing is specified by the purchaser or cognizant engineering organization. See 8.6 and 4.4.3. 4.2.2.1 Periodic testing may be suspended in any test period when parts are not processed, however, preprodu
30、ction testing may be required by the purchaser or cognizant quality organization upon resumption of processing 4.2.3 Preproduction Tests All property verification tests (section 3.4) are preproduction tests and shall be performed prior to or on the initial shipment of coated parts to a purchaser and
31、 when the purchaser or cognizant engineering organization requires confirmatory testing. 4.3 Sampling for Testing 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 (3.2 and 3.3), in not
32、longer than 8 consecutive hours, and presented for processors inspection at one time. Unless the purchaser or cognizant engineering organization provides a sampling plan, the minimum number of samples shall be as shown in Table 1. Examination shall be made with the unaided eye. TABLE 1 SAMPLING FOR
33、ACCEPTANCE TESTING Number of Parts in Lot Quality 5 or less All 6 to 50 5 51 to 90 7 91 to 150 11 151 to 280 13 281 to 500 16 501 to 1200 19 1201 to 3200 23 4.3.1 Periodic Tests Five test panels are required for corrosion resistance tests. Two test panels are required for primer adhesion tests. SAE
34、INTERNATIONAL AMS2473H Page 5 of 6 4.3.2 Specimen configuration Test specimens for corrosion and primer adhesion shall be 0.025 to 0.063 inch (0.64 to 1.60 mm) thick and not less than 3 10 inches (76 x 254 mm) in width and length fabricated from 2024-T3 aluminum alloy in accordance with AMS4037 proc
35、essed in accordance with 3.2 and 3.3. 4.4 Approval 4.4.1 The process and control factors, a preproduction sample part, or both, whichever is specified, shall be approved by the cognizant engineering organization before production parts are supplied. 4.4.2 If the processor makes a significant change
36、to any material, process, or control factor from that which was used for process approval, all preproduction tests 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
37、significant change is one that, in the judgment of the cognizant engineering organization, could affect the properties or performance of the coated parts. 4.4.3 Control factors for the process shall include, but not be limited to, the following: Surface preparation Type of bath used Composition limi
38、ts for coating solution Processing temperature limits Drying temperature Frequency of processing solution analysis Periodic test plan for cleaning and processing solutions. See 8.6. 4.5 Reports The processor of coated parts shall furnish with each shipment a report stating that the parts have been p
39、rocessed and tested in accordance with specified requirements and that they conform to the acceptance test requirements. This report shall include the purchase order number, lot number, AMS2473H, part number, and quantity. 4.6 Resampling and Retesting 4.6.1 If any acceptance test fails to meet speci
40、fied requirements, parts in that lot may be stripped, pretreated, coated as defined herein, and retested. Alternatively, all parts in the lot may be inspected for the nonconforming attribute and the nonconforming parts may be stripped, pretreated, coated as defined herein, and tested. 4.6.1.1 When s
41、tripping is performed, the method shall be approved by the cognizant engineering organization and shall not roughen, pit, or adversely affect part dimensions. When parts have been stripped and replated, the purchaser shall be informed. 4.6.2 If any periodic test fails to meet specified test requirem
42、ents, the process is nonconforming. No additional parts shall be coated until the process is corrected and new specimens are coated and tested. Results of all tests shall be recorded and, when requested, reported. Purchaser shall be notified of all parts coated since the last acceptable test. 5. PRE
43、PARATION FOR DELIVERY 5.1 Coated parts shall be handled and packaged to ensure that the required physical characteristics and properties of the coating are preserved. 5.2 Packages of coated parts shall be prepared for shipment in accordance with commercial practice and in compliance with applicable
44、rules and regulations pertaining to the handling, packaging, and transportation of the coated parts to ensure carrier acceptance and safe delivery. SAE INTERNATIONAL AMS2473H Page 6 of 6 6. ACKNOWLEDGMENT A processor shall mention this specification number and its revision letter in all quotations a
45、nd when acknowledging purchase orders. 7. REJECTIONS Parts on which the coating does not conform to this specification, or to modifications authorized by purchaser, will be subject to rejection. 8. NOTES 8.1 A change bar (|) located in the left margin is for the convenience of the user in locating a
46、reas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor i
47、n documents that contain editorial changes only. 8.2 The parts manufacturer should ensure that the surfaces of the metal parts supplied to the processor are free from blemishes, pits, tool marks, and other irregularities that will affect the quality of the finished parts. Imperfections and variation
48、s in appearance that arise from surface conditions of the substrate, such as porosity, scratches, or inclusions, that persist in the coating despite the observance of accepted industry practices shall not be cause for rejection. 8.3 Exposure of chromated parts to temperatures over 140 F (60 C) may a
49、dversely affect the corrosion protective properties. The effect is most readily apparent on 2XXX and 7XXX series alloys. 8.4 Coatings may be transparent and typically range from iridescent yellow to olive green or bluish. Cast parts may exhibit more color variation than parts fabricated from wrought materials. 8.5 A corrosion pit or spot can usually be distinguished from other indications by a tail or line of corrosion p
