1、 NOT MEASUREMENT SENSITIVE MIL-DTL-5541F 11 July 2006 SUPERSEDING MIL-C-5541E 30 November 1990 DETAIL SPECIFICATION CHEMICAL CONVERSION COATINGS ON ALUMINUM AND ALUMINUM ALLOYS This specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. Th
2、is specification covers chemical conversion coatings formed by the reaction of chemical conversion materials with the surfaces of aluminum and aluminum alloys. 1.2 Classification. The chemical conversion coatings are of the following types and classes. 1.2.1 Types. The chemical conversion coatings a
3、re of the following types (see 3.1): Type I Compositions containing hexavalent chromium. Type II Compositions containing no hexavalent chromium. 1.2.2 Classes. The materials, which form protective coatings by chemical reaction with aluminum and aluminum alloys, are of the following classes (see 6.1
4、and 6.4). Class 1A - For maximum protection against corrosion, painted or unpainted. Class 3 - For protection against corrosion where low electrical resistance is required. Comments, suggestions, or questions on this document should be addressed to: Commander, Naval Air Warfare Center Aircraft Divis
5、ion, Code 491000B120-3, Highway 547, Lakehurst, NJ 08733-5100 or emailed to thomas.omaranavy.mil. Since contact information can change, you may want to verify the currency of this address information using the ASSIST Online database at http:/assist.daps.dla.mil. AMSC N/A AREA MFFP Provided by IHSNot
6、 for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-5541F 2 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this section are specified in sections 3 or 4 of this specification. This section does not include documents cited in other sections of this sp
7、ecification or recommended for additional information or as examples. While every effort has been made to ensure the completeness of this list, document users are cautioned that they must meet all specified requirements of documents cited in sections 3 or 4 of this specification, whether or not they
8、 are listed. 2.2 Government documents. 2.2.1 Specifications and standards. The following specifications and standards form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract. FEDERAL STANDA
9、RDS FED-STD-141 - Paint, Varnish, Lacquer and Related Materials: Methods of Inspection, Sampling and Testing DEPARTMENT OF DEFENSE SPECIFICATIONS MIL-PRF-23377 - Primer Coatings: Epoxy, High-Solids MIL-DTL-81706 - Chemical Conversion Materials for Coating Aluminum and Aluminum Alloys MIL-PRF-85582 -
10、 Primer Coatings: Epoxy, Waterborne (Copies of these documents are available online at http:/assist.daps.dla.mil/quicksearch or http:/assist.daps.dla.mil or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094.) 2.3 Non-Government publications. T
11、he following documents form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract. AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM) INTERNATIONAL ASTM-B117 - Salt Spray (Fog) Apparatus, Opera
12、ting. (DoD adopted) ASTM-D3359 - Adhesion By Tape Test, Measuring. (DoD adopted) (Copies of these documents are available from ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959 or http:/www.astm.org.). Provided by IHSNot for ResaleNo reproduction or networking permitted wit
13、hout license from IHS-,-,-MIL-DTL-5541F 3 AMERICAN SOCIETY FOR QUALITY (ASQ) ASQ-Z1.4 - Procedures, Sampling and Tables for Inspection by Attributes (Copies of this document are available from American Society for Quality, 600 North Plankinton Ave., Milwaukee, WI 53203 or http:/www.asq.org.) SOCIETY
14、 OF AUTOMOTIVE ENGINEERS (SAE) INTERNATIONAL SAE-AMS4027 - Aluminum Alloy, Sheet and Plate, 1.0Mg-0.60Si-0.28Cu- 0.20Cr, (6061; -T6 Sheet, -T651 Plate) Solution and Precipitation Heat Treated. (DoD adopted) SAE-AMS4037 - Aluminum Alloy, Sheet and Plate, 4.4Cu-1.5Mg-0.60Mn, (2024; -T3 Flat Sheet; -T3
15、51 Plate) Solution Heat Treated. (DoD adopted) (Copies of these documents are available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001 or http:/www.sae.org.) 2.4 Order of precedence. In the event of a conflict between the text of this document and the references cited here
16、in, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 Materials. If no material type is specified type I shall be used. Unless otherwise specified in the contrac
17、t or order, substitutions of either type I for type II, or type II for type I coatings are not permitted. The materials used to produce a chemical conversion coating shall be approved for the selected type, class, form, and application method in accordance with the qualification requirements of MIL-
18、DTL-81706 and shall have been accepted for listing on the applicable qualified products list (see 6.5). Replenishing chemicals, such as fluorides, added to a bath to maintain its efficiency, shall not degrade the performance of the coating being applied. 3.2 Cleaning. Prior to coating, the base meta
19、l shall be mechanically or chemically cleaned such that a water break-free surface is obtained after rinsing (see 6.6). Abrasives containing iron such as steel wool, iron oxide, rouge, or steel wire are prohibited for all cleaning operations. Treated parts that have become soiled shall be cleaned wi
20、th materials that will remove the soil without damaging the base metal, the part, or the conversion coating. If the coating is damaged, the damaged area shall be recleaned and recoated or the part shall be rejected. 3.3 Application. Unless an application method is specified in the contract or order
21、Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-5541F 4 (see 6.4), the chemical conversion coating shall be applied nonelectrolytically by spray, brush, or immersion after all heat treatments and mechanical operations such as forming, perfora
22、ting, machining, brazing, and welding have been completed (see 6.11 and 6.14). Assemblies containing nonaluminum parts that may be attacked, embrittled, or damaged in any way by the conversion coating process shall not be coated as assemblies unless the nonaluminum parts are masked. 3.4 Touch-up. If
23、 specified in the contract or order, mechanically damaged areas from which the coating has been removed shall be touched up or rejected. The damaged areas shall be touched up with MIL-DTL-81706 material approved on QPL-81706 for the applicable type, class, form, and method. The area to be touched up
24、 shall be not greater than 5 percent of the total item surface area (see 6.4 and 6.17). 3.5 Appearance. The chemical conversion coating shall be continuous in appearance and visibly discernible in daylight. It shall be free from areas of powdery or loose coating, voids, scratches, flaws, and other d
25、efects or damages which reduce the serviceability of parts or are detrimental to the protective value and paint bonding characteristics. The size and number of contact marks shall be minimal, consistent with good practice. If specified in the contract or order, contact marks shall be touched up with
26、 MIL-DTL-81706 material approved on QPL-81706 for the applicable type, class, form, and method to prevent localized corrosion (see 6.4 and 6.8). 3.6 Performance characteristics. 3.6.1 Corrosion resistance. At the end of 168 hours of exposure to the 5 percent salt spray test specified in 4.4.1, test
27、specimens (see 4.2.2) treated with the applicable class of coating shall meet the following corrosion resistance requirements (see 6.14): a. No more than 5 isolated spots or pits (see 6.9), none larger than 0.031 inch in diameter, per test specimen. Areas within 0.25 inch from the edges, identificat
28、ion markings, and holding points during processing or salt spray exposure shall be excluded. Loss of color shall not be cause for rejection. b. No more than 15 isolated spots or pits, none larger than 0.031 inch in diameter, on the combined surface area of all five test specimens, subjected to the s
29、alt spray test. 3.6.2 Paint adhesion (wet tape). When the production paint system (6.13) or the paint system specified in 4.2.2.1.1 is applied to the applicable test specimens (see 4.2.2), no intercoat separation shall occur between the paint system and the conversion coating, or between the convers
30、ion coating and the base metal, when tested in accordance with 4.4.2 (an adhesion rating of 4A or better according to ASTM-D3359 Procedure A) (see 6.12). If the conversion coated parts do not require painting for end use, the paint adhesion test may be omitted if specifically authorized by the acqui
31、sition activity (see 6.4). Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-5541F 5 3.7 Electrical contact resistance of class 3 coatings. Electrical contact resistance testing shall be as specified in the contract or order (see 6.4). The test
32、 method, frequency of testing, and required resistance values shall be specified by the acquisition activity to meet the needs of a particular application (see 6.1.2.1). 3.8 Chemical analysis of the conversion solution. Chemical analysis of the conversion solution shall consist of concentration, pH,
33、 and temperature evaluations to determine that the bath is within the ranges specified by the chemical manufacturer (see 6.11). 3.9 Workmanship. The chemical conversion coatings covered by this specification shall be produced by treatments and processes that produce coated components as specified in
34、 this specification. 4. VERIFICATION 4.1 Classification of inspections. The inspection requirements specified herein are classified as follows: a. Process control inspection (see 4.2). b. Conformance inspection (see 4.3). 4.2 Process control inspection. 4.2.1 Process control tests and solution analy
35、sis. Test specimens shall be tested in accordance with table I and 4.2.1.1. In addition to the tests in table I, solution analysis shall be performed on all the processing solutions in the chemical conversion line (see 3.8) to verify that the chemical concentrations are within ranges established for
36、 optimum performance (see 6.11 and 6.14). Process control tests are conducted to determine compliance of the chemical conversion coatings with the requirements of this specification and are acceptable as evidence of the properties being obtained with the equipment and procedures employed. TABLE I. P
37、rocess control tests. Tests Class Number of test specimens Test specimen preparation paragraph Requirement paragraph Test paragraph Corrosion resistance 1A 3 5 5 4.2.2 4.2.2 3.6.1 3.6.1 4.4.1 4.4.1 Wet tape adhesion 1A 3 2 2 4.2.2-4.2.2.14.2.2-4.2.2.1 3.6.2 3.6.2 4.4.2 4.4.2 Electrical contact resis
38、tance 3 5 4.2.2 3.7 4.4.1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-5541F 6 4.2.1.1 Frequency of process control testing and solution analysis. Solution analysis shall at a minimum be performed once every week (see 6.15). The process co
39、ntrol tests specified in table I shall at a minimum be conducted on a monthly basis. In addition, the interval between each monthly test shall not exceed 35 days. If production in accordance with this specification is not performed for 35 days or more, process control tests and solution analysis sha
40、ll be conducted at the restart of production. 4.2.2 Process control test specimens. Test specimens used for process control testing shall be 3 inches wide, 10 inches long, with a nominal thickness of not less than 0.020-inch. The test specimens shall be processed with the hardware during an actual p
41、roduction run, including all pre- and post-treatment processes such as cleaning and rinsing, except as specified below. Unless otherwise specified in the contract or order (see 6.4), either of the following alloy options for the process control test specimens shall be used: Option 1 - A set of test
42、specimens shall be used for each alloy and temper treated during the monthly process control period. Option 2 - The test specimens shall be 2024-T3 aluminum alloy in accordance with SAE-AMS4037 for class 1A coatings and 6061-T6 aluminum alloy test specimens in accordance with SAE-AMS4027 for class 3
43、 coatings. Aluminum alloy 2024-T3 test specimens may be used in lieu of 6061-T6 test specimens for testing class 3 coatings (see 6.10). When castings are being processed and the cleaning procedures used are detrimental to the wrought test specimens, the test specimens shall be cleaned in a proper ma
44、nner (see 3.2) and the conversion coated with the castings. If the production parts are not 2024-T3 aluminum alloy and the etch or deoxidizer may be detrimental to the test specimens, the manufacturers recommended cleaning practices shall be used. 4.2.2.1 Preparation of paint adhesion specimens. Unl
45、ess otherwise specified on the contract or order (see 6.4), the paint system to be used on the test specimens for adhesion testing (see 4.4.2 and 6.13) shall be the same system used for the production work (applied and cured in the same manner as the production work) or the paint system specified in
46、 4.2.2.1.1. 4.2.2.1.1 Epoxy primer coatings. Test specimens shall be furnished with one coat of a volatile organic compound (VOC) compliant epoxy-polymide primer conforming to MIL-PRF-23377 or MIL-PRF-85582. In either case, the primer shall be applied to a dry film thickness of 0.0006 to 0.0009 inch
47、 (0.6 to 0.9 mil) and dried in accordance with the applicable primer specification before testing in accordance with 4.4.2. 4.2.3 Failure. Failure to conform to any of the process control requirements specified in table I shall result in immediate cessation of production. The reason for failure shal
48、l be determined and corrected before production resumes. All traceable and retrievable work from the last acceptable process control test to the time when the failure was determined shall be rejected, unless the work under review can be demonstrated to meet the requirements of this Provided by IHSNo
49、t for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-5541F 7 specification. Unless otherwise specified, parts that have been painted or incorporated into an assembly shall not be considered retrievable. 4.3 Conformance inspection. 4.3.1 Sampling. Samples for visual examinations shall be selected from each lot (see 4.3.2) of treated articles, items, parts, or compo
