SAE AMS 2466C-2018 Hard Anodic Coating of Magnesium Alloys.pdf

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 2018 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:/standards.sae.org/AMS2466C AEROSPACE MATERIAL SPECIFICATION AMS2466 REV. C Issued 1997-07 Revised 2018-01 Superse

5、ding AMS2466B Hard Anodic Coating of Magnesium Alloys RATIONALE AMS2466C results from a Five-Year Review and update of this specification. Changes were made to the title differentiate AMS2466 from AMS2467 and to paragraph 3.4.3 Wear Resistance. NOTICE ORDERING INFORMATION: The following information

6、shall be provided to the processor by the purchaser. 1) Purchase order shall specify not less than the following: AMS2466C Basis metal to be anodized Class (1.3) Special instructions, such as post-treatment (3.3.4). Quantity of pieces to be anodized 2) Parts manufacturing operations such as heat tre

7、ating, 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 not controlled by this specification. 1. SCOPE 1

8、.1 Purpose This specification covers the requirements for a hard anodic coating on magnesium alloys. 1.2 Application This coating has been used typically to provide corrosion resistance and abrasion resistance to cast magnesium alloys, but usage is not limited to such applications. SAE INTERNATIONAL

9、 AMS2466C Page 2 of 8 1.3 Classification Anodic finishes are classified by coating thickness as follows: Class 1 Thin Coating: Coating thickness in the range of 0.0002 to 0.0004 inch (5 to 10 m). Class 1H Heavy Coating: Coating thickness in the range of 0.0005 to 0.0007 inch (13 to 18 m). Class 2 Th

10、ick Coating: Coating thickness in the range of 0.0008 to 0.0010 inch (20 to 25 m). 1.3.1 If a class is not 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

11、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 saf

12、ety of all personnel involved. 2. APPLICABLE DOCUMENTS The issue of the following documents in effect on the date of the purchase order forms a part of this specification to the extent supplied herein. The supplier may work to a subsequent revision of a document unless a specific document issue is s

13、pecified. When the referenced document has been cancelled 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

14、 Canada) or +1 724-776-4970 (outside USA), www.sae.org. AMS4418 Magnesium Alloy Castings, Sand Castings, 2.5Ag-2.1Di-0.70Zr (QE22A-T6), Solution and Precipitation Heat Treated AMS4429 Magnesium Alloy Castings, Sand Castings, 2.8Nd-1.4Gd-0.4Zn-0.6Zr (EV31A-T6), Solution and Precipitation Heat Treated

15、 AMS4439 Magnesium Alloy Castings, 4.2Zn - 1.2Rare Earths - 0.70Zr, (ZE41A-T5), Precipitation Heat Treated AMS4446 Magnesium Alloy Castings, Sand Castings, 8.7Al - 0.70Zn - 0.26Mn, (AZ91E - T6), Solution and Precipitation Heat Treated ARP1917 Clarification of Terms Used in Aerospace Metals Specifica

16、tions ARP4992 Periodic Test Plan for Processing Solutions AS2390 Chemical Process Test Specimen Material SAE INTERNATIONAL AMS2466C Page 3 of 8 2.2 ASTM Publications Available from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm

17、.org. ASTM B117 Operating Salt Spray (Fog) Apparatus ASTM B244 Measurement of Thickness of Anodic Coatings on Aluminum and of Other Nonconductive Coatings on Nonmagnetic Basis Metals With Eddy-Current Instruments ASTM B487 Measurement of Metal and Oxide Coating Thickness by Microscopical Examination

18、 of a Cross Section ASTM D1193 Reagent Water ASTM D1654 Evaluation of Painted or Coated Specimens Subjected to Corrosive Environments ASTM D4060 Abrasion Resistance of Organic Coatings by the Taber Abraser 3. TECHNICAL REQUIREMENTS 3.1 Equipment 3.1.1 Tanks shall be fabricated from, or lined with, a

19、 material that is compatible with the baths used for cleaning, pretreatment, anodizing, or post-treatment solutions and shall be equipped with temperature controls capable of controlling the bath temperatures within specified limits. 3.1.2 Fixtures Hooks, clamps, and racks used to suspend parts in t

20、he electrolyte, and which are in contact with the electrolyte, shall be fabricated from magnesium or magnesium alloys, or from aluminum alloys containing magnesium (5000 or 6000 series). Such fixtures shall be protected with suitable maskant at the electrolyte-air interface. 3.2 Preparation 3.2.1 Ti

21、ght electrical contact shall be maintained during the anodic treatment to prevent contact arcing (burning) of parts, but small irregularities of coating at points of electrical contact are acceptable. For parts which are to be anodized all over, locations shall be acceptable to purchaser. For parts

22、which are not to be anodized all over, locations shall be in areas on which anodize is not required. 3.2.2 Parts shall have clean surfaces, free from water break, prior to immersion in the anodizing solution. See 8.3. 3.3 Procedure 3.3.1 Pretreatment The cleaned parts shall be immersed for 30 to 90

23、minutes in an aqueous solution of 83 to 102 grams per liter ammonium fluoride solution, with a pH of 6.0 to 6.8, and operated at 160 to 180 F (71 to 82 C) followed by a water rinse. SAE INTERNATIONAL AMS2466C Page 4 of 8 3.3.2 Anodizing shall be accomplished in an aqueous, chromate-free, alkaline el

24、ectrolyte with the parts made the anode using voltage and current densities that produce an anodize coating conforming to specified properties. During anodizing, parts shall be oriented so as to prevent gas entrapment. 3.3.3 After coating, part shall be thoroughly rinsed in cold running water and dr

25、ied. 3.3.4 Post-Treatment When post-treatment is specified, parts shall be immersed in a bath containing 108 to 132 grams per liter sodium dihydrogen phosphate (NaH2PO4) in water meeting ASTM D1193, Type IV, maintained at a pH of 4.3 to 4.5 and a temperature of 115 to 125 F (46 to 52 C). Immersion t

26、ime shall be 30 to 60 seconds for Class 1 or 1H and 1 to 2 minutes for Class 2. Post treatment shall be followed by rinsing in cold water, hot reagent water, and drying. 3.4 Properties Coated parts shall conform to the following requirements: 3.4.1 Coating thickness shall be 0.0002 to 0.0004 inch (5

27、 to 10 m) for Class 1 coatings, 0.0005 to 0.0007 inch (13 to 18 m) for Class 1H, and 0.0008 to 0.0010 inch (20 to 25 m) for Class 2 coatings, determined in accordance with any of the following methods as applicable: ASTM B244, ASTM B487, or other method acceptable to the cognizant engineering organi

28、zation. 3.4.2 Corrosion Resistance For each Class anodized during the month, coated samples shall be subjected for not less than the applicable time shown in Table 1 to salt spray corrosion test in accordance with ASTM B117. The exposed surfaces of the panels shall show a rating of nine or greater a

29、fter exposure, determined in accordance with ASTM D1654, procedure B. Corrosion resistance of coatings applied to other alloys may be specified by the cognizant engineering organization. Table 1 - Corrosion resistance requirements Panel Material Coating Class Salt Spray Resistance Hours AMS4439 1 24

30、 AMS4439 2 72 AMS4446 1 168 AMS4446 2 336 AMS4429 1 168 AMS4429 2 336 AMS4418 1 24 AMS4418 2 72 3.4.3 Wear Resistance Coated panels of AMS4439, AMS4418 and AMS4446 shall exhibit a wear index value less than 30 and a wear cycle rating greater than 5000 cycles for each 0.001 inch (25 m) coating thickn

31、ess when tested in accordance with ASTM D4060 except that the CS-17 wheel shall be resurfaced after every 1000 cycles by running it for a minimum of 25 cycles against the resurfacing medium, S-11 abrasive disk. Panels may be placed in a desiccator prior to and following testing to establish constant

32、 weight in lieu of conditioning specified in ASTM D4060. Wear resistance test is applicable to all coating classes. Wear resistance requirements for coatings on other alloys may be specified by the cognizant engineering organization. Coated panels of AMS4429 shall exhibit a wear index value less tha

33、n 35 and a wear cycle rating greater than 5000 cycles for each 0.001 inch (25 m) coating thickness when tested in accordance with ASTM D4060 except that the CS-17 wheel shall be resurfaced after every 1000 cycles by running it for a minimum of 25 cycles against the resurfacing medium, S-11 abrasive

34、disk. Wear resistance test is applicable to all coating classes. Panels may be placed in a desiccator prior to and following testing to establish constant weight in lieu of conditioning specified in ASTM D4060. Wear resistance requirements for coatings on other alloys may be specified by the cogniza

35、nt engineering organization. SAE INTERNATIONAL AMS2466C Page 5 of 8 3.4.4 Electrical Continuity Coatings shall not conduct electricity when tested with a properly functioning, conventional, low-voltage continuity or resistance tester or the specific instrument specified by the cognizant engineering

36、organization. Contact the surface of the anodic-coated part with the leads. Monitor the instrument for conduction of electricity. 3.5 Quality Surfaces of coated parts, as received by purchaser, shall be uniform in texture and appearance except at the points of electrical contact and in pockets where

37、 gas was unavoidably trapped during processing. Powdery areas, laminations, pits, and other evidence of burning are not acceptable. Darkened corners or edges and excessive buildup are not acceptable. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for Inspection The processor shall supply all tes

38、t panels when required for processors tests, and shall be responsible for the performance of all required tests. When parts are to be tested, the parts shall be supplied by purchaser. The cognizant engineering organization reserves the right to sample and to perform any confirmatory testing deemed n

39、ecessary to ensure that processing conforms to specified requirements. 4.2 Classification of Tests 4.2.1 Acceptance Tests Coating thickness (3.4.1) and quality (3.5) are acceptance tests and shall be performed on parts, or specimens representing parts when permitted herein, from each lot. See 4.3.3.

40、1. 4.2.2 Periodic Tests Corrosion resistance (3.4.2) wear resistance (3.4.3) and electrical continuity (3.4.4) are periodic tests and shall be performed at least monthly unless frequency of testing is specified by the cognizant engineering organization. Tests of the cleaning and processing solutions

41、 are periodic tests and shall be performed at a frequency established by the processor unless frequency of testing is specified by the cognizant engineering organization. See 8.5 and 4.4.3. 4.2.3 Preproduction Tests All property verification tests (see 3.4) are preproduction tests and shall be perfo

42、rmed prior to production and when the cognizant engineering organization requires confirmatory 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, coated in the same b

43、aths in not longer than 8 consecutive hours, and presented for processors inspection at one time. Unless the cognizant engineering organization provides a sampling plan, the minimum number of samples shall be in accordance with Table 2. SAE INTERNATIONAL AMS2466C Page 6 of 8 Table 2 - Sampling for a

44、cceptance tests Number of Parts in Lot Quality (Visual) Thickness 1 to 6 All All or 3* 7 to 15 7 4 16 to 40 10 4 41 to 110 15 5 111 to 300 25 6 301 to 500 35 7 501 to 700 50 8 701 to 1200 75 10 Over 1200 125 15 *Whichever is less 4.3.2 Periodic and Preproduction Tests Sample quantities shall be not

45、less than three for corrosion, one for electrical continuity, and one for wear resistance unless otherwise specified by the cognizant engineering organization. 4.3.3 Sample Configuration 4.3.3.1 Separate test specimens may be used under any one of the following circumstances: The parts are of such c

46、onfiguration 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 destructive tests on actual parts. Except as specified below, acceptance test specimens shall be made of the same generic c

47、lass of alloy as the parts, established in accordance with AS2390, distributed within the lot, cleaned, anodized, and post treated with the parts. 4.3.3.2 Corrosion resistance test panels shall be a minimum of 4 x 5 inches (102 x 127 mm). 4.4 Approval 4.4.1 Process and control factors, a preproducti

48、on sample, or both, whichever is specified by purchaser, 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

49、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 significant change is one which, in the judgment of the cognizant engineering organization, could affect the properties or performance of the coating. 4.4.3 Control factors shall include, but not be l