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 theref
2、rom, 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 2016 SAE InternationalAll rights reserved. No part of this publi
3、cation 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: +1 724-776-4970 (out
4、side USA)Fax: 724-776-0790Email: CustomerServicesae.orgSAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedbackon this Technical Report, please visithttp:/www.sae.org/technical/standards/ARP6400AEROSPACERECOMMENDED PRACTICEARP6400Issued 2010-10Reaffirmed 2016-05Recommended Practi
5、ce for Processing and Handling Wire and Cablewith Silver Plated Conductors and ShieldsRATIONALEARP6400 has been reaffirmed to comply with the SAE five-year review policy.1. SCOPE This ARP specifies the recommended methods of handling silver coated conductors and shield, by the conductor fabricator,
6、wireinsulator, distributors, harness or assembly houses, and OEMs. Red Plague mitigation depends upon each link in the chain of supply handling the wire and cable properly. 2. REFERENCES The following publications form a part of this document to the extent specified herein. The latest issue of SAE p
7、ublications shall apply. The applicable issue of the other publications shall be the issue in effect on the date of the purchase order. In the event of conflict between the text of this document and references cited herein, the text of this document takes precedence. Nothing in this document, howeve
8、r, supersedes applicable laws and regulations unless a specific exemption has been obtained. The following document provides further information which the user may find helpful in understanding cupous/cupric oxide corrosion of silver coated conductors and shields. 2.1 SAE Publications Available from
9、 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. AIR4487A Investigation of Silver Plated Conductor Corrision (Red Plague) 3. APPLICABLE DOCUMENTS 3.1 ASTM Publications Available from ASTM Inte
10、rnational, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org. ASTM D-5486 Standard Specification for Pressure-Sensitive Tape for Packaging, Box Closure, and Sealing 3.2 U.S. Government Publications Available from the Document Automation and Produ
11、ction Service (DAPS), Building 4/D, 700 Robbins Avenue, Philadelphia, PA 19111-5094, Tel: 215-697-6257, http:/assist.daps.dla.mil/quicksearch/. MIL-D-3464 Desiccants, Activated, Bagged, Packaging Use and Static Dehumidification MIL-DTL-29606 Wire, Electrical, Stranded, Uninsulated Copper, Copper All
12、oy, or Aluminum, or Thermocouple Extension, General Specification for. MIL-P-23242B Plastic Coating Compound, Strippable, for Electroplating MS20003 Indicator, Humidity, Card, Three Spot, Impregnated Areas (Cobaltous Chloride) 4. GENERAL DESIGN REQUIREMENTSSilver coated wire and shields shall meet t
13、he requirements of MIL-DTL-29606. 5. PROCEDURES5.1 General Environmental Conditions 5.1.1 Temperature and humidity conditions warrant attention. When humidity is high, a small temperature difference can cause condensation on conductor and insulation surfaces. Caution is therefore warranted when movi
14、ng silver coated copper material to or through areas lacking adequate environmental controls. Bagging the material is useful for protecting against condensation while the wire or cables temperature stabilizes. 5.1.2 Storage duration: Storage of wire or cable for longer than one (1) year should be mi
15、nimized if at all possible, and good commercial practices of first in first out inventory management should be practiced. Material stored for longer than one (1) year should be examined for evidence of corrosion and if it is still acceptable, be repackaged with a new desiccant. 5.1.3 Storage Areas:
16、Should be a dry area, and away from any possible exposure to water. Humidity controlled rooms with less than 50% humidity are recommended for long term storage where practical. If the storage area is not temperature/humidity controlled, then material should be stored in bags with dessicants. Bagging
17、 material, if used for packaging, should be polyethylene. Storage conditions for the desiccant (MIL-D-3464), Type II and determination of its use quantity per package should be in accordance with the desiccant manufacturers instructions. Humidity indicator cards per MS20003-2 should also be placed i
18、n the bag and monitored to determine if the desiccant should be replaced. 5.1.4 Material movement: On-site material movement out of or into an air conditioned location, and off site transportation through variable environments, can cause moisture condensation. Therefore temperature and humidity cond
19、itions need be considered in preparation for these material movements. Sealed bags are useful for protecting against this condensation while the wire is allowed to temperature stabalizes at the new location. Note: Some common packaging materials, such as paper wrapping, rubber bands, and cardboard b
20、oxes may contain and offgas small ammounts of sulfur which can attach the silver plating. 5.2 Conductor and Shield Manufacturers 5.2.1 Plating: The coating of the copper or copper alloy conductors is critical to the long term quality of the material. The plating thickness need be sufficiently thick,
21、 non-porous, and unpitted to avoid exposure of the underlying copper. Therefore platers need ensure that the coating is applied with best commercial practices. 5.2.2 Drawing: Silver coating damage may occur during the drawing process. The conductor manufacturer needs to have good quality controls to
22、 verify that this process in no way damages the plating. A die inspection plan should be implemented to ensure that dies are replaced if damaged which can cause reductions in silver coating thickness or exposed copper. SAE INTERNATIONAL ARP64002 OF 45.2.3 Stranding: Assembly of the individual strand
23、s need to be performed with great care, particullarly along the outer edge of the strands which come in direct contact with the closing machinery. Contact points in the conductor path as well as the closing die needs to be inspected under magnification as part of an inspection plan inorder to verify
24、 that it is smooth and free of any damage. Upon completion of the process the conductors should be inspected to verify that the plating has not been reduced below minimum requirements and that no exposure of copper has occurred. Inspection results should be tracked using statistical process control
25、as specified in MIL-DTL-29606 and should include plating thickness, and concentricity. 5.2.4 Additional Storage notes (See 5.1): Silver coated copper or copper alloy conductor and shield material should be packaged and stored in a sealed container with a desiccant and humidity indicator card. Conduc
26、tors should be packaged during storage using Silver Saver vapor corrosion inhibitor (VCI) paper, or equivalent to prevent silver tarnish. 5.3 Wire Insulators/Processors 5.3.1 Additional Storage notes (See 5.1): Silver coated copper or copper alloy conductor and shield material should be packaged and
27、 stored in a sealed container with a desiccant and humidity indicator card. Un-insulated conductors should be packaged during storage using Silver Saver vapor corrosion inhibitor (VCI) paper, or equivalent to prevent silver tarnish. When a partial reel is used for manufacturing the conductor should
28、be rewrapped with the VCI paper and then placed in a sealed bag with a new desiccant, prior to being returned to inventory 5.3.2 Insulating and jacketing: Water quenching of extrusions should be avoided when possible, and no production operation should be employed that involves direct contact of sil
29、ver coated copper or copper alloy conductors or shields with water or aqueous solutions. All sheaves, or rollers should be free turning, and without damage. Any tips should be inspected to verify the core is smooth and does not contain burrs. 5.3.3 Shielding: Silver coated copper and copper alloy br
30、aids are particularly susceptible to corrosion due to mechanical fabrication damage associated with the braiding process. Manufacturers should inspect all surfaces over which the braid ends pass during the braiding process to find and correct surface anomalies that may cause damage. Most braiders us
31、e a closing loop or die to form the braid around the core. These should also be inspected prior to use. 5.3.4 Final Packaging: Wire and cable ready to ship should be packaged using good commercial practices. The ends of the cable should be sealed after final electrical verification with either ends
32、caps and military approved sealing tape (per ASTM D5486) or a non oil containing hot dip material (MIL-P-23242B). The reel should then be packaged in a polyethylene bag with a dessicant and humidity indicator in the same manner as the un-insulated wire. Storage of Silver coated wire and cable after
33、manufacture should be minimized whenever possible, and inventory should be on a first in first out basis. Material which has been stored for longer than one (1) year should be stripped back and examined for evidence of corrosion before it is shipped. All ends must be re-sealed and then repackaged wi
34、th a new desiccant and humidity indicator card in preparation for shipment. 5.3.5 Labeling: It is recommended that manufacturers place a label or tag stating “Caution: Improper handling of silver plated conductors and shields may lead to corrosion issues. For more information refer to AIR4487A and A
35、RP6400.” 5.4 Distributors 5.4.1 Receiving: Material which is received can be inspected, but should be carefully removed from the sealed bags. Any ends which are cut for inspection must be resealed. The wire or cable should then be immediately resealed in the bag with the dessicant and humidity indic
36、ator card. 5.4.2 Cut lengths: Wire or cable which is removed and repackaged should follow the same packaging procedures as the wire insulator prior to shipment. Any material which is left on the reel should have the ends resealed with either ends caps and military approved sealing tape (per ASTM D54
37、86) or a non oil containing hot dip material (MIL-P-23242B). The wire or cable should then be repackaged in a sealed bag with a new desiccant and humidity indicator card. 5.4.3 Final Packaging: Distributors should follow the same practices for shipment as the wire insulators, and should include the
38、same precautionary label. See Section 5.3 5.4.4 Storage: See note 5.1 SAE INTERNATIONAL 3 OF 4ARP64005.5 Harness or Assembly Manufacturers 5.5.1 Processing: No production operation should be employed that involves direct contact of silver coated copper or copper alloy with water or aqueous solutions
39、. Dipping of exposed wire ends into etching solutions with associated rinses, or aqueous cleaning of solder flux residue are examples of procedures to avoid. 5.5.2 Production material movements: The corrosion risk is diminished when the wire and cable has been sealed, thus limiting the opportunity f
40、or moisture intrusion. Caution remains warranted for work in progress assemblies that have cut wire ends exposed to the ambient air environment. It is important to avoid condensation when moving silver coated copper materials between different temperature environments. If the environment in storage,
41、 kitting, and the production areas is approximately the same, then condensation risk is low and special precautions for material movement are not needed. If the enviroment in storage, kitting and/or the production areas is not the same, then condensation risk exists, precaution is needed and sealed
42、bags are recommended. See 5.1 for material movement. 5.5.3 Cut lengths: Production material movement recommendations should be observed, especially for unsealed wire or cable ends that will enable moisture intrusion. Any material which is left on the reel and is not immediately being used for produc
43、tion should be sealed in bags or have the ends sealed. Wire or cable which is going back into storage should follow the recommendations is section 5.1. 5.5.4 Product examination: In-process examination should be performed when insulation is absent or removed for wire termination or other purposes. P
44、ersonnel responsible for examining wire should receive training in the identification of red plague corrosion to ensure understanding of the condition and continued vigilance to look for it. 5.5.5 Shipment: Harnesses designs with cut ends exposed to ambient air environments, should be sealed in bags
45、 with a dessicant prior to shipment to prevent moisture exposure during transport. See note 5.1. 5.5.6 Storage: See note 5.1 5.6 OEM 5.6.1 Processing: No production operation should be employed that involves direct contact of silver coated copper or copper alloy with water or aqueous solutions. Dipp
46、ing of exposed wire ends into etching solutions with associated rinses, or aqueous cleaning of solder flux residue are examples of procedures to avoid. 5.6.2 Production material movements: The corrosion risk is diminished when the wire and cable has been sealed, thus limiting the opportunity for moi
47、sture intrusion. Caution remains warranted for work in progress assemblies that have cut wire ends exposed to the ambient air environment. It is important to avoid condensation when moving silver coated copper materials between different temperature environments. If the environment in storage, kitti
48、ng, and the production areas is approximately the same, then condensation risk is low and special precautions for material movement are not required. If the enviroment in storage, kitting and/or the production areas is not the same, then condensation risk exists, precaution is needed and sealed bags
49、 are recommended. See 5.1 for material movement. 5.6.3 Cut lengths: Production material movement recommendations should be observed, especially for unsealed wire or cable ends that will enable moisture intrusion. Any material which is left on the reel and is not immediately being used for production should be sealed in bags or have the ends sealed. Wire or cable which is going ba
