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 reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2011 SAE International All rights reserved. No part of this publication m
3、ay 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: +1 724-776-4970 (outside U
4、SA) 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/AMS2429D AEROSPACE MATERIAL SPECIFICATION AMS2429 REV. D Issued 1985-10 Reaffirmed 2006-09 Re
5、vised 2011-10Superseding AMS2429C Plating, Bronze Nitriding Stop-off 90Cu - 10Sn RATIONALE AMS2429D results from a Five Year Review and update of this specification. NOTICE ORDERING INFORMATION: The following information shall be provided to the plating processor by the purchaser. 1) Purchase order
6、shall specify not less than the following: AMS2429D Basis metal to be plated Tensile strength or hardness of the basis metal Special features, geometry or processing present on parts that requires special attention by the plating processor If stress relief treatment in accordance with 3.1 has been p
7、erformed or is not required If an alternative of the ferricyanide test method is to be used (See 4.3.3.3). Hydrogen embrittlement relief to be performed if different from 3.3. Quantity of pieces to be plated 2) Parts manufacturing operations such as heat treating, forming, joining and media finishin
8、g can affect the condition of the substrate for plating, or if performed after plating, could adversely affect the plated 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. SAE AMS2
9、429D Page 2 of 7 1. SCOPE 1.1 Purpose This specification covers the requirements for electrodeposited bronze plate and subsequent removal . 1.2 Application This process has been used typically as a maskant to prevent nitriding of surfaces on which nitriding is neither required nor permitted, but usa
10、ge is not limited to such applications. 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 u
11、se. 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 The issue of the following documents in effect o
12、n 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 cancelled and no superseding document has been specifi
13、ed, 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. AS2390 Chemical Process Test Specimen Material 2.
14、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.org. ASTM B 487 Measurement of Metal and Oxide Coating Thicknesses by Microscopical Examination of a Cross Section ASTM B 499 Measurement of Coat
15、ing Thicknesses by the Magnetic Method; Nonmagnetic Coatings on Magnetic Basis Metals ASTM B 504 Measurement of Thickness of Metallic Coatings by the Coulometric Method ASTM B 567 Measurement of Coating Thicknesses by the Beta Backscatter Method ASTM B 568 Measurement of Coating Thickness by X-Ray S
16、pectrometry ASTM B 571 Adhesion of Metallic Coatings ASTM E 376 Measuring Coating Thickness by Magnetic-Field or Eddy-Current (Electromagnetic) Test Methods ASTM E 478 Chemical Analysis of Copper Alloys ASTM F 519 Mechanical Hydrogen Embrittlement Evaluation of Plating Processes and Service Environm
17、ents SAE AMS2429D Page 3 of 7 3. TECHNICAL REQUIREMENTS 3.1 Preparation 3.1.1 Stress Relief Treatment All steel parts having a hardness of 40 HRC and above and that are machined, ground, cold formed or cold straightened shall be cleaned to remove surface contamination and thermally stress relieved b
18、efore plating for the relief of residual tensile stresses. Residual tensile stresses have been found to be damaging during electrofinishing. Parts having a core hardness less than 55 HRC, shall be stress relieved at 375 F 25 for a minimum of 4 hours. Nitrided parts fall into this category. Higher te
19、mperatures shall only be used when specified or approved by the cognizant engineering organization. 3.1.2 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 req
20、uirements. 3.1.3 Except for barrel plating, electrical contact shall be as follows. For parts which are to be plated all over, locations shall be acceptable to purchaser. For parts which are not to be plated all over, locations shall be in areas on which plating is not required. 3.1.4 Auxiliary anod
21、es shall be used as necessary to ensure proper plate thicknesses in holes, recesses, and closed-end deep bores on parts to be protected against nitriding. 3.2 Procedure 3.2.1 Parts shall be plated by electrodeposition of copper-tin alloy from a suitable bronze plating solution. A preliminary strike
22、of copper or, for corrosion and heat resistant steels, of nickel is permissible. 3.2.2 After plating, the parts shall be thoroughly rinsed and dried. 3.2.3 After nitriding, the bronze plate shall be stripped from parts with an alkaline copper stripper that will not roughen, pit, embrittle or cause o
23、ther damage to the basis metal. 3.3 Hydrogen Embrittlement Relief After plating, parts having hardness higher than 40 HRC shall be baked for not less than 23 hours at 375 F 10 (191 C 6) or shall be started in the nitriding cycle within 4 hours after plating. 3.4 Properties The deposited copper-tin a
24、lloy shall conform to the following requirements: 3.4.1 Thickness Thickness shall be not less than 0.0005 inch (13 m) on all surfaces not to be nitrided determined in accordance any of the following methods as applicable: ASTM B 487, ASTM B 499, ASTM B 504, ASTM B 567, ASTM B 568, and ASTM E 376 or
25、other method acceptable to cognizant engineering organization. 3.4.1.1 Where “copper strike“ or “nickel strike“ is specified, the thickness of the strike shall be approximately 0.0001 inch (2.5 m). 3.4.2 Composition The tin content of the bronze plate shall be 5 to 15% by weight, determined by wet c
26、hemical methods in accordance with ASTM E 478, by spectrochemical methods, or by other analytical methods acceptable to the cognizant engineering organization. SAE AMS2429D Page 4 of 7 3.4.3 Adhesion shall be tested on parts, or specimens representing parts, using the heat quench test for copper in
27、accordance with ASTM B 571. 3.4.4 Porosity The plate shall be sufficiently nonporous to not give a blue color when tested in accordance with 4.3.3.3. Contact marks that turn blue shall not be cause for rejection. 3.4.5 Hydrogen Embrittlement The plating and stripping process shall not cause embrittl
28、ement in ferrous metals determined in accordance with 4.3.3.4. 3.5 Quality Plating, as received by purchaser, shall be continuous, adherent to basis metal, uniform in appearance, and essentially free from blisters, nodules, pits, and other surface imperfections. Slight staining or discoloration is p
29、ermissible. After nitriding and stripping, the part surface shall be free from excessive roughness, pitting or other damage to the basis metal. There shall be no residual plating, including any applied strike, remaining on surfaces that were plated. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility
30、 for Inspection The processor shall supply all samples 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 an
31、y confirmatory testing deemed necessary to ensure that processing conforms to the specified requirements. 4.2 Classification of Tests 4.2.1 Acceptance Tests Thickness (3.4.1), adhesion (3.4.3), porosity (3.4.4), and quality (3.5) are acceptance tests and shall be performed on parts, or specimens rep
32、resenting parts when permitted herein, from each lot (See 4.3.3). 4.2.2 Periodic Tests Composition (3.4.2) and hydrogen embrittlement (3.4.5) are periodic tests and be performed monthly unless frequency of testing is specified by the cognizant engineering organization.Tests of cleaning and plating s
33、olutions 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 8.7 and 4.4.4). 4.2.2.1 Periodic testing may be suspended in any test period when parts are not processed, however, p
34、reproduction testing may be required by the cognizant quality organization upon resumption of processing. 4.2.3 Preproduction Tests All property verification tests (3.4) are preproduction tests and shall be performed prior to production or on the initial shipment of plated parts to a purchaser and w
35、hen the cognizant engineering organization requires confirmatory testing. SAE AMS2429D Page 5 of 7 4.3 Sampling and Testing 4.3.1 Acceptance Tests Test samples shall be randomly selected from all parts in the lot. A lot shall be all parts of the same part number plated in a continuous series of oper
36、ations (3.2 and 3.3) 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 as shown in Table 1. TABLE 1 - Sampling for Acceptance Tests Lot Size Qualit
37、y Thickness Porosity Adhesion Destructive Test (when required) Up to 7 7 to 15 16 to 40 41 to 110 111 to 300 301 to 500 501 to 700 701 to 1200 All 7 10 15 25 35 50 75 All or 3* 4 4 5 6 7 8 10 0 0 1 2 3 4 5 6 *Whichever is less 4.3.2 Periodic Tests Sample quantity for composition shall be at the disc
38、retion of the processor unless otherwise specified by the cognizant engineering organization. For hydrogen embrittlement, sample size is specified in ASTM F 519 unless otherwise specified by the cognizant engineering organization (See 4.3.3.4). 4.3.3 Sample Configuration Nondestructive testing shall
39、 be performed wherever practical. Except as noted, actual parts shall be selected as samples for tests. When representative specimens are used for acceptance testing, values so obtained shall be correlated with those of parts since properties, such as thickness, may differ between parts and represen
40、tative test specimens. 4.3.3.1 Representative test specimens may be used in lieu of parts under any one of the following circumstances: The plated 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
41、 is not economically acceptable to perform destructive tests on actual parts., or for the porosity tests where residual ferricyanide-salt is not desired on actual parts. Except as specified below, representative test specimens shall be made of the same generic class of alloy as the parts, establishe
42、d in accordance with AS2390, distributed within the lot, cleaned, plated, and post treated with the parts represented. 4.3.3.2 For adhesion and thickness tests, specimens shall be either: (a) bars approximately 0.5 inch (13 mm) in diameter and 4 inches (102 mm) long or (b) strips or panels approxima
43、tely 1 x 4 inch (25 x 102 mm). 4.3.3.3 Bronze plated panels shall be immersed for not less than 5 minutes in potassium ferricyanide solution made up in accordance with Table 2. Another test method shall only be used when approved by the cognizant engineering organization (See 8.5). SAE AMS2429D Page
44、 6 of 7 TABLE 2 - FERRICYANIDE TEST SOLUTION Ingredient Amount Potassium ferricyanide 10 grams Sodium chloride 5 grams Reagent water 100 mL 4.3.3.4 Hydrogen Embrittlement Test Test shall be in accordance with the requirements of ASTM F 519 Type 1a.1 using round notched specimens, unless a different
45、specimen is specified by the cognizant engineering organization, stressed in tension under constant load. For test purposes, the plate thickness shall be 0.0005 inch (13 m) measured on the smooth section of the specimen, but with visual plate at the root of the notch. 4.4 Approval 4.4.1 The process
46、and control factors, a preproduction sample part, and/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 to any material, process, or control factor from that which was u
47、sed 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 significant change is one which, in the judgment of the cognizant
48、 engineering organization, could affect the properties or performance of the parts. 4.4.3 Control factors shall include, but not be limited to, the following: Surface preparation method(s) Composition and temperature limits of the plating bath Testing frequency for plating bath composition Periodic
49、test plan Method of thickness determination Periodic test plan for cleaning and processing solutions (See 8.7). 4.5 Reports The processor of plated 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 numbe
