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 2012 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/AMS2454 AEROSPACE MATERIAL SPECIFICATION AMS2454 Issued 2012-04 Plating, Electrol
5、ess Nickel, Codeposited with Polytetrafluoroethylene (PTFE) RATIONALE This specification establishes the requirements for an electroless nickel plate that is codeposited with polytetrafluoroethylene (PTFE). This plating has been demonstrated to meet Code “T” of MIL-DTL-38999. NOTICE ORDERING INFORMA
6、TION: The following information shall be provided to the plating processor by the purchaser. 1. Purchase order shall specify not less than the following: AMS2454, Service Class (Table 1), Grade Number (Table 2), Grade Letter (Table 3), Type (Table 4). Optional: Class of Thermal Treatment (1.3.4). Sp
7、ecial features, geometry, or processing present on parts that requires special attention by the plating processor. Quantity of pieces to be plated. Basis metal to be plated. Tensile strength or hardness of the basis metal (applicable to steel alloys only). Optional: Pre-plate stress relief to be per
8、formed by plating processor (time and temperature), if different from 3.1.1. Optional: Requirement to prohibit hexavalent chromium use, when applicable (3.2.4). Optional: Hydrogen embrittlement relief to be performed by plating processor, if different from 3.3.1. Optional: Requirement to remove resi
9、dual PTFE particles, if applicable, and method of removal, if desired (3.3.3, 3.5.1, and 8.14). Optional: Specific requirement(s) and test method(s) for color and/or gloss, when applicable (3.5.2). Optional: Requirement for adhesion testing of parts by chisel-knife or other method, and frequency of
10、test, if required (3.4.2.2 or 3.4.2.3). SAE AMS2454 Page 2 of 13 Optional: Periodic testing, if required (4.2.2.2), for Corrosion Resistance (3.4.3), Coefficient of Friction (3.4.7), and/or Adhesion Testing of Parts (3.4.2.1 or 3.4.2.2) and periodic test sample quantity, if different than 4.3.2. Opt
11、ional: Shot peening, if required, on steel parts having a hardness of 40 HRC or above (8.11). Optional: Requirement and test method for corrosion testing of plated parts, when applicable (8.16). Optional: Requirement for control of maximum plating thickness (total plating buildup), when applicable (
12、8.17). Optional: Requirement and test method for wear resistance, when applicable (8.18). Optional: Requirement(s) and test method(s) for control of PTFE particle size and/or distribution, when applicable (8.19). Optional: Requirement and test method for electrical conductivity, when applicable (8.2
13、0). Optional: Requirement and test method for internal stress, when applicable (8.21). 2. Part manufacturing operations such as heat treating, forming, joining and media finishing can affect the condition of the substrate for plating, or if performed after plating, could adversely affect the plated
14、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. See 8.2. SAE AMS2454 Page 3 of 13 1. SCOPE 1.1 Purpose This specification covers the requirements for electroless nickel plate tha
15、t is codeposited with polytetrafluoroethylene (PTFE) over other materials. 1.2 Application This deposit has been used typically to provide a uniform build-up on intricate shapes for improvement of wear resistance, low reflectivity, and/or as an electrically conductive finish with improved corrosion
16、resistance, but usage is not limited to such applications. The deposit is generally dark and nonreflective. The deposit has been used in service up to 500 F (260 C) although wear and/or corrosion resistance may degrade as service temperature increases. 1.2.1 Corrosion resistance is a function of sub
17、strate material and the type and thickness of underplate and the electroless nickel PTFE composite surface layer. See 8.16. 1.2.2 This plating is not specifically intended for applications requiring premium solderability or adhesive bondability. See 8.15. 1.2.3 Application of electroless nickel PTFE
18、 composite plating to steel parts having a hardness of 46 HRC (ultimate tensile strength of 220 ksi (1517 MPa) or higher) shall not be performed unless authorized by the design documentation or specific approval has been received from the cognizant engineering organization. 1.3 Classification The co
19、gnizant engineering organization may assign one or more of the following classifications to specify plating requirements: 1.3.1 Service Class Designates Corrosion Resistance (See 3.4.3 and 8.16) TABLE 1 - CORROSION RESISTANCE (1)Service Class Duration of Salt Spray Test (Hours) SC0 Not Required SC1
20、48 SC2 100 SC3 192 SC4 500 SC5 1000 SC6 2000 (1)Specifying a Service Class requires appropriate decisions for Grade and Type. See 8.16. SAE AMS2454 Page 4 of 13 1.3.2 Grade Designates Thickness (See 3.4.1 and 8.16) TABLE 2 - PTFE-NICKEL COMPOSITE LAYER THICKNESS (MINIMUM) Grade (1)Inches Micron 1 0.
21、0001 2.5 m 2 0.0003 7.6 m 3 0.0007 18 m (1)Other thickness requirements shall be as-specified by purchaser TABLE 3 - UNDERPLATE LAYER (1)THICKNESS (MINIMUM) Grade (2)Inches Micron A 0.00005 1.25 m B 0.0001 2.5 m C 0.0002 5.0 m D 0.0003 7.5 m E 0.0005 12.5 m F 0.0007 17.5 m G 0.0010 25.0 m H 0.0014 3
22、0.0 m (1)Multiple underplate layers may be applied, as determined by plating processor. (2)Other thickness requirements shall be as-specified by purchaser 1.3.3 Type Designates Phosphorus Content of Plating (See 3.4.6, 8.8, and 8.16) TABLE 4 - PHOSPHORUS CONTENT OF PLATING Type Phosphorus, % by Weig
23、ht I No requirement II 1 to 3 III 3 to 5 IV 5 to 9 V 9 and above 1.3.4 Class Designates Thermal Treatment (See 3.3.2, 3.4.4, 8.6, and 8.12) Class 1: Except for hydrogen embrittlement relief, no post plating thermal treatment. Class 2: Thermal treatment at 450 F (232 C) to harden the deposit. Class 3
24、: Thermal treatment at 375 F (191 C). Class 4: Thermal treatment at 250 F (121 C). Unless a specific class is specified, Class 1 or Class 4 may be supplied. 1.4 Safety - Hazardous Materials While the materials, methods, applications, and processes described or referenced in this specification may in
25、volve the use of hazardous materials, this specification does not address the hazards which may be involved in such use. It is the 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 healt
26、h and safety of all personnel involved. SAE AMS2454 Page 5 of 13 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 specified herein. The supplier may work to a subsequent revision of a document un
27、less 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 document shall apply. 2.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001
28、, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. AMS2759/9 Hydrogen Embrittlement Relief (Baking) of Steel Parts AS2390 Chemical Process Test Specimen Material 2.2 ASTM Publications Available from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West C
29、onshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org. ASTM B 117 Operating Salt Spray (Fog) Testing Apparatus ASTM B 487 Measurement of Metal and Oxide Coating Thicknesses by Microscopical Examination of a Cross Section ASTM B 499 Measurement of Coating Thicknesses by the Magnetic Method: Non
30、magnetic Coatings on Magnetic Basis Metals ASTM B 567 Method for Measurement of Coating Thickness by the Beta Backscatter Method ASTM B 568 Measurement of Coating Thickness by X-Ray Spectrometry ASTM B 571 Qualitative Adhesion Testing of Metallic Coatings ASTM B 578 Micro-Hardness of Electroplated C
31、oatings. ASTM B 636 Measurement of Internal Stress of Plated Metallic Coatings with the Spiral Contractometer ASTM B 748 Measurement of Thickness of Metallic Coatings by Measurement of Cross Section with a Scanning Electron Microscope ASTM B 764 Simultaneous Thickness and Electrochemical Potential D
32、etermination of Individual Layers in Multilayer Nickel Deposit (STEP Test) ASTM D 1894 Static and Kinetic Coefficient of Friction of Plastic Film and Sheeting ASTM E 384 Microhardness of Materials ASTM F 519 Mechanical Hydrogen Embrittlement Evaluation of Plating/Coating Processes and Service Enviro
33、nments SAE AMS2454 Page 6 of 13 3. TECHNICAL REQUIREMENTS 3.1 Preparation 3.1.1 Stress Relief Treatment Steel parts having a hardness of 40 HRC (180 ksi) or higher and which have been ground after heat treatment shall be cleaned to remove surface contamination and suitably stress relieved before pre
34、paration for plating. Unless otherwise specified, the stress relief temperature shall not be less than 275 F (135 C) for not less than 5 hours for parts having hardness of 55 HRC (300 ksi) or higher or not less than 375 F (191 C) for not less than 4 hours for other parts. See 8.11 for information ab
35、out peening. 3.1.2 Cleaning The plating shall be applied over a surface free from water breaks. The cleaning procedure shall not produce pitting or intergranular attack of the basis metal and shall preserve dimensional requirements. 3.2 Procedure 3.2.1 Plating shall be performed by chemical depositi
36、on of a nickel-phosphorus PTFE composite onto a properly prepared surface. The deposit may consist of a single layer of nickel-phosphorus PTFE composite plating or of multilayer plating containing an external layer that includes electroless nickel PTFE composite. Underplate composition, if applied,
37、shall be as selected by the plating processor. 3.2.1.1 Multilayer plating shall be conducted without interruption to ensure good layer to layer adhesion. 3.2.2 Plated parts shall be removed from the plating solution, thoroughly rinsed, and dried. 3.2.3 Double plating and spotting in are prohibited.
38、See 8.9.1. 3.2.4 When specified by purchaser, the plating process shall not include hexavalent chromium. 3.3 Post Treatment 3.3.1 Hydrogen Embrittlement Relief Hydrogen embrittlement relief treatment of steel parts shall be in accordance with AMS2759/9. Other metals and alloys do not require hydroge
39、n embrittlement relief baking. 3.3.2 Heat Treatment for Hardness or Adhesion Enhancement When Class 2, 3, or 4 is specified, parts shall be thermally treated after plating, rinsing, and drying. 3.3.2.1 When Class 2 is specified, parts shall be heated to 450 F 15 (232 C 8) for a minimum of 4 hours to
40、 increase hardness of the deposit. See 3.4.4 and 8.6. Hydrogen embrittlement relief (3.3.1) may be omitted if Class 2 hardening is accomplished within 4 hours after plating. 3.3.2.2 When Class 3 is specified, parts shall be heated to 375 F 15 (191 C 8) for 1 to 2 hours. 3.3.2.3 When Class 4 is speci
41、fied, parts shall be heated to 250 F 10 (121 C 6) for 1 to 2 hours. 3.3.3 When specified by purchaser, residual PTFE particles loosely bonded to the surface shall be removed using a method permitted by the cognizant engineering organization. See 3.5.1 and 8.14. SAE AMS2454 Page 7 of 13 3.4 Propertie
42、s Plating shall conform to the following requirements: 3.4.1 Thickness Unless otherwise specified, thickness shall meet the requirements of Tables 2 and 3, determined in accordance with any of the following methods as applicable: ASTM B 487, ASTM B 499, ASTM B 567, ASTM B 568, ASTM B 748, ASTM B 764
43、, or by other method permitted by the cognizant engineering organization. See 8.17. 3.4.2 Adhesion 3.4.2.1 Adhesion on representative test panels shall meet the requirements of ASTM B 571, using the 180 degree bend test method with a 4T mandrel. 3.4.2.2 When specified, adhesion on parts shall meet t
44、he requirements of ASTM B 571 using the chisel-knife test method. 3.4.2.3 When specified by the cognizant engineering organization, adhesion may be tested by other test method appropriate to the part configuration and product application; for example, crush testing of connectors with adhesion at the
45、 fracture interface evaluated as in 3.4.2.2. 3.4.3 Corrosion Resistance Representative plated test panels in accordance with 4.3.3.3 shall show no lifting of the plating, no exposure of the basis metal, and no visual evidence of corrosion of the basis metal after being subjected to the continuous sa
46、lt spray corrosion test conducted in accordance with ASTM B 117. Duration of test shall be in accordance with the specified Service Class shown in Table 1. See 8.16. 3.4.4 Hardness Class 2 nickel-PTFE plating hardness shall be not lower than 300 HK25, or equivalent, determined in accordance with AST
47、M E 384 or ASTM B 578. See 3.3.2.1. 3.4.5 Hydrogen Embrittlement The plating process shall not cause hydrogen embrittlement in steel parts, after baking, determined in accordance with 4.3.3.4. 3.4.6 Composition Unless specified otherwise, the phosphorus content shall be as shown in Table 4. Other th
48、an nickel, residual metals and nonmetals in the deposit shall not exceed 1% total by weight. Other composition requirements shall be as specified by cognizant engineering organization. 3.4.7 Coefficient of Friction The coated specimens (4.3.3.5) tested in accordance with ASTM D 1894 or other method
49、permitted by the cognizant engineering organization shall have a maximum coefficient of friction of 0.20. 3.5 Quality Plating, as received by purchaser, shall be smooth, continuous, and uniform in appearance and shall be free from frosty areas, pinholes, blisters, and other imperfections detrimental to usage of the plate. Water marks from rinsing, slight stainin
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