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 2013 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/J1974_201303 SURFACE VEHICLE RECOMMENDED PRACTICE J1974 MAR2013 Issued 1993-06 St
5、abilized 2013-03 Superseding J1974 JUN1993 Decorative Anodizing Specification for Automotive Applications RATIONALE The Materials, Processes, and Parts Council has not found users for this Recommended Practice, nor is there technical expertise to determine if updates are necessary. Therefore this st
6、andard has been Stabilized. STABILIZED NOTICE This document has been declared “Stabilized“ by the SAE Materials, Processes and Parts Council and will no longer be subjected to periodic reviews for currency. Users are responsible for verifying references and continued suitability of technical require
7、ments. Newer technology may exist. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J1974 Stabilized MAR2013 Page 1 of 8 1. SCOPE This SAE Recommended Practice is aimed at ensuring high-quality pr
8、oducts of anodized aluminum automotive components in terms of durability and appearance. Decorative sulfuric acid anodizing has been well developed over the last several decades in the aluminum industry. Exterior and interior performance demonstrated that parts processed to this document meet long-t
9、erm durability requirements. Since the treatment of processing variables is outside the scope of this document, it is important for applicators of this coating to develop an intimate knowledge of their process, and control all parameters that affect the quality of the end product. The use of techniq
10、ues such as statistical process control (SPC), capability studies, design of experiments, process optimization, etc., are critical to produce material of consistently high quality. 1.1 Form Detailed in this SAE Recommended Practice are interior and exterior bright or electrolytically colored anodize
11、d aluminum automotive components in the form of seat trim, dashboard, window or side body mouldings, bumpers, wheels, rocker panel, etc. 1.2 Application This document defines performance requirements for bright or electrolytically colored anodized aluminum finishes including interior and exterior ap
12、plications. The automotive parts can be fabricated from bare coiled sheet, flat sheet, or extruded shapes. Preanodized coiled sheet may be applicable for selected applications. Alloy selection is governed by finish requirements, forming characteristics, and mechanical properties. Copyright SAE Inter
13、national Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J1974 Stabilized MAR2013 Page 2 of 8 2. REFERENCES 2.1 Applicable Documents The following ASTM methods form a part of this specification to the extent specified herei
14、n. The latest version of the single copy document shall apply. 2.1.1 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 137 Measurement of Weight of Coating on Anodically Coated Aluminum
15、ASTM B 368 Copper-Accelerated Acetic Acid-Salt Spray (Fog) Testing (CASS Test) ASTM B 487 Measurement of Metal and Oxide Thicknesses by Microscopical Examination of a Cross Section ASTM B 680 Seal Quality of Anodic Coatings on Aluminum by Acid Dissolution ASTM B 681 Measurement of Thickness of Anodi
16、c Coatings on Aluminum and of Other Transparent Coatings on ASTM Opaque Surfaces, Using the Light-Section Microscope ASTM D 2197 Standard Test Method for Adhesion of Organic Coatings by Scrape Adhesion ASTM E 430 Measurement of Gloss of High Gloss Surfaces by Goniophotometry ASTM G 23 Operating Ligh
17、t-Exposure Apparatus (Carbon-Arc Type) With and Without Water for Exposure of Nonmetallic Materials 3. DEFINITIONS 3.1 GLOSS Degree to which a surface simulates a perfect mirror in its capacity to reflect light. 3.2 HAZE Diffuse scattering of reflected light in directions adjacent to the direction o
18、f specular or mirror reflection. 3.3 PICKUP A mixture of aluminum fines, lubricant, and aluminum oxide generated from roll coating during the deformation process. 3.4 SIGNIFICANT SURFACES These are defined as surfaces that are visible when the finished component is assembled onto the vehicle and is
19、observed in normal viewing position. Nonvisible surfaces, when designated by the customer, are significant. 3.5 STRINGERS Usually a mixture of magnesium and aluminum oxides that results from inadequate molten metal treatment. Copyright SAE International Provided by IHS under license with SAENot for
20、ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J1974 Stabilized MAR2013 Page 3 of 8 3.6 SYMBOLS AND ABBREVIATIONS g80m Micrometer or micron mil 0.001 Inch g/m2Grams per Square Meter mg/dm2Milligrams per Square Decimeter g/cm3Grams per Cubic Centimeter MJ/m2Megajoules
21、per Square Meter g113F degrees Fahrenheit g113C degrees Celsius ASTM American Society for Testing and Materials A.D.T. Acid Dissolution Test CASS Copper Acidified Salt Spray 4. TECHNICAL REQUIREMENTS 4.1 Quality 4.1.1 Substrate Preparation The substrate surface finish can affect the anodized appeara
22、nce. Suitable precautions in forming, cleaning, and chemical brightening must be taken to assure a satisfactorily finished part. 4.1.2 Surface Appearance Samples representing typical production parts should be used to define the appearance levels established by automotive companies in cooperation wi
23、th anodizers and aluminum companies. Anodized surfaces shall have the following general physical appearance: a. Free of physical defects such as scratches, etc. b. Acceptable levels of stringers, pickup, etc. c. Color, gloss, and haze requirements as per master samples Copyright SAE International Pr
24、ovided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J1974 Stabilized MAR2013 Page 4 of 8 4.2 Tolerances 4.2.1 Coating Thickness/Weight For automotive bright trim components, the most critical requirement is anodic coating thickne
25、ss/weight. The coating thickness/weight has a direct impact on the appearance and durability. Thinner coatings generally give brighter appearance but less durability as compared to thicker coatings. Field exposure has shown that properly applied clear finishes provide durability while maintaining ac
26、ceptable appearance. Despite the lack of similar long-term field service experience, the black electrolytic finish appears to provide adequate durability based on several years of experience. The anodizing thickness/weights listed in Table 1 shall be met on all areas of the significant surfaces. TAB
27、LE 1 - MINIMUM COATING THICKNESS AND WEIGHT REQUIREMENT FOR CLEAR AND ELECTROLYTIC BLACK FINISHES Thickness1(Min) Exterior Thickness(1)(Min) Interior Coating Weight2(Min) Exterior Coating Weight(2)(Min) Interior Clear Finish 7.5 g80m 2.5 g80m 20 g/m26 g/m2(0.3 mil) (0.1 mil) Electrolytic Black 15.0
28、g80m37.5 g80m(3)40 g/m2420 g/m2 (4)(Tin or Nickel Base) (0.6 mil) (0.3 mil) Electrolytic Black 7.5 g80m(3)57.5 g80m(3)20 g/m2(4)20 g/m2(4)(Cobalt Base) (0.3 mil) (0.3 mil) 4.2.2 Seal Quality - Test Method - ASTM B 680 The Acid Dissolution Test (A.D.T.) is based on the concept that the resistance to
29、dissolution of the anodic coating in the phosphoric-chromic acid solution is indicative of the effectiveness of the sealing operation. The amount of anodic coating dissolved is expressed as a mass in mg/dm2or in an A.D.T. “rating“ unit independent of coating thickness. In the automobile industry in
30、North America, the A.D.T. “rating“ unit is widely used. The maximum value for the “rating“ unit is 6.0, which is equivalent to 20 mg/dm2based on a coating density of 2.62 g/cm3. The formulas used to determine the units, as well as interrelationship of the A.D.T. units for various coating thicknesses
31、, are presented in Appendix A and B, respectively. 1Coating ThicknessASTM B 681; ASTM B 487 2Coating WeightASTM B 137 3Thicker coatings may be needed to meet requirements of color and gloss. 4Coating weight should be determined on an equivalent clear sealed coating prior to electrolytic coloring. 5C
32、oating thickness requirements for bumper application using 7029 alloy, using a Cobalt based electrolyte must minimum of 15.0 g80m (0.60 mil). Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J1974
33、 Stabilized MAR2013 Page 5 of 8 The following Acid Dissolution Test (A.D.T.) requirements must be met to achieve acceptable field durability: a. Clear Finish - 20 mg/dm2max (6 rating) b. Electrolytic Black - 20 mg/dm2max (6 rating) 4.2.3 Accelerated Corrosion - Test Method - ASTM B 368 The CASS test
34、 shall be carried out in strict accordance with ASTM B 368. Collection rates, ph, and specific gravity should preferably be run with every CASS test cycle. The copper accelerated acetic acid salt spray or CASS test is presently the most widely used accelerated corrosion test in the automotive indust
35、ry. The CASS test is not used to predict the number of years a part may last in service, but rather to evaluate the integrity of the metal finish. The CASS test does not have an exact correlation to years of corrosion protection in service. Failure to pass the test may be regarded as a probable indi
36、cation of early failure in service. The corrosion rating listed in Table 2 is required to maintain the high quality standards of the automotive industry and achieve acceptable field durability: TABLE 2 - CORROSION RATING REQUIREMENT FOR CLEAR AND ELECTROLYTIC BLACK FINISHES Exterior Interior Clear F
37、inish no pitting or corrosion after 6 h N/A Electrolytic Black no pitting or corrosion after 6 h N/A 4.2.4 Optical Properties The glossy appearance (brightness) of a high gloss metal finish can be determined in accordance with ASTM E 430. Acceptable levels of optical properties are to be established
38、 by automotive companies in cooperation with anodizers and aluminum suppliers. Master samples with representative optical properties are recommended for comparison. 4.2.5 New Alloys And/or New Processes Additional tests have been suggested to qualify new alloys and/or new finishing processes for aut
39、omotive applications of decorative anodized products. 4.2.5.1 Scratch Resistance - ASTM D 2197 (suggested apparatus is Pacific Balanced Beam Scrape-Adhesion and Mar Tester, Model SG-8101) For information purposes, some typical scratch widths on an anodized surface using a 500 g weight with loop styl
40、us SG-8102 are as follows: a. AA-5657-H25 is 500 to 600 g80m b. AA-5252-H25 is 400 to 500 g80m c. AA-7029-T6 is 200 to 300 g80m Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J1974 Stabilized MA
41、R2013 Page 6 of 8 4.2.5.2 Heat Finish should not craze or show signs of physical damage at a metal temperature up to 90 g113C (194 g113F). 4.2.5.3 Weatherometer - ASTM G 23 - Method 3 (Carbon-Arc Type) Finish should not turn yellow, change color, fade, or show signs of chalking after 1000 h exposure
42、 at a black panel temperature of 63 g113C (145 g113F). 4.2.5.4 Outdoor Exposure (Exterior) - Direct Weathering in Florida Samples to be exposed 5 degrees off horizontal facing south. Sample(s) will be examined at intervals 175 000 langleys (or 7322 MJ/m2or approximately 12 months) and 350 000 langle
43、ys (or 14 644 MJ/m2or approximately 24 months). No corrosion, color change, or color fading is allowed. 4.2.5.5 Outdoor Exposure (Interior) - Under Glass Exposure in Florida Samples to be exposed under glass at 5 degrees off horizontal facing south. Sample(s) will be examined at intervals 175 000 la
44、ngleys (or 7322 MJ/m2or approximately 12 months) and 350 000 langleys (or 14 644 MJ/m2or approximately 24 months). No corrosion, color change, or color fading is allowed. PREPARED BY THE SAE DECORATIVE ANODIZING SUBCOMMITTEE OF THE SAE BRIGHT TRIM EXECUTIVE COMMITTEE STABILIZED BY THE SAE MATERIALS,
45、 PROCESSES AND PARTS COUNCIL Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J1974 Stabilized MAR2013 Page 7 of 8 APPENDIX A FORMULAS USED FOR CALCULATIONS A.1 A.D.T. results in: mg dm2g101W1W2A1
46、-=(Eq. A1) mg in2g101W1W2A2-=(Eq. A2) %W1W2W1W3-100 %g117=(Eq. A3) A.D.T. Rating UnitW1W2W1W3-200 T1;#23#23#23#23#23#23#23#23#23#23#23;#23#23#23#23#23#23#23#23#23#23#23#23g117W1W2A2-4.652;#23#23#23#23#23#23#23#23#23#23#23;#23#23#23#23#23#23#23#23#23#23#23#23g117;=(Eq. A4) where: W1- W2= weight of co
47、ating, in mg, dissolved in chromic-phosphoric acid solution as per ASTM B 680 W1- W3= total coating weight, in mg, as per ASTM B 137 A1= area of test specimen in dm2A2= area of test specimen in in2T = coating thickness in mils NOTE 1: (1)As specified in G.M. FBTM 55-46; FORD FLTM BQ 72; Chrysler LP
48、461A-241 NOTE 2: (2)As specified in Chrysler LP 461A-241 (alternate procedure) Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J1974 Stabilized MAR2013 Page 8 of 8 APPENDIX B INTERRELATIONSHP OF A.D.T. UNITS FOR VARIOUS COATING THICKNESSES B.1 See Table B1. TABLE B1 - INTERRELATIONSHIP OF A.
