1、Designation: F1110 09 (Reapproved 2014)Standard Test Method forSandwich Corrosion Test1This standard is issued under the fixed designation F1110; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number i
2、n parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 This test method defines the procedure for evaluatingthe
3、corrosivity of aircraft maintenance chemicals, when presentbetween faying surfaces (sandwich) of aluminum alloys com-monly used for aircraft structures. This test method is intendedto be used in the qualification and approval of compoundsemployed in aircraft maintenance operations.1.2 The values sta
4、ted in SI units are to be regarded as thestandard. The values given in parentheses are for information.1.3 This standard may involve hazardous materials,operations, and equipment. This standard does not purport toaddress all of the safety concerns, if any, associated with itsuse. It is the responsib
5、ility of the user of this standard toestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.Specific hazard statements appear in Section 9.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD1748 Test Met
6、hod for Rust Protection by Metal Preserva-tives in the Humidity CabinetG46 Guide for Examination and Evaluation of Pitting Cor-rosion2.2 Industry Standards:3SAE-AMS-QQ-A-250/4 Al Alloy 2024, Plate and SheetSAE-AMS-QQ-A-250/5 Al Alloy Alclad 2024, Plate andSheetSAE-AMS-QQ-A-250/12 Al Alloy 7075, Plat
7、e and SheetSAE-AMS-QQ-A-250/13 Al Alloy Alclad 7075, Plate andSheet2.3 Military Specification:MIL-A-8625 Anodic Coatings forAluminum andAlAlloys43. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 sandwich corrosion testa comparative acceleratedenvironmental test of the corrosivit
8、y of liquid or solid materialspresent between faying surfaces of structural aluminum alloyscommonly used in aerospace construction.4. Summary of Test Method4.1 Aluminum coupons having clad or anodized noncladsurfaces are sandwiched together with a filter paper saturatedwith the test material between
9、 the coupons. The sandwichedcoupons are cycled between warm ambient air and warmhumid air for 7 days. The coupons are then inspected todetermine whether corrosion more severe than that caused byreagent water has occurred on the surfaces exposed to the testmaterial. This test method is used for solut
10、ions of dry granularmaterial or for liquid materials.5. Significance and Use5.1 The data generated by this test method shall be used todetermine whether aircraft structural aluminum alloys areliable to be corroded or damaged by application of the testmaterial during routine maintenance operations.5.
11、2 Interpretation of the sandwich corrosion test results isbased on a comparison of the appearance of faying surfaces ofthree sets of coupons. One set of test coupons is exposed withreagent water only in the faying surfaces, to establish thebaseline (controls) against which the panels exposed to the
12、testmaterial are compared. Disregard corrosion at cut edges of thetest coupons.5.3 The relative corrosion severity rating system is providedin order to allow a numerical classification of the test resultsand to eliminate the necessity for elaborate weight lossmeasurements. Pitting corrosion, which i
13、s rated 4extensive(severe) corrosion, may involve only a negligible weight loss.1This test method is under the jurisdiction of ASTM Committee F07 onAerospace and Aircraft and is the direct responsibility of Subcommittee F07.07 onQualification Testing of Aircraft Cleaning Materials.Current edition ap
14、proved Dec. 1, 2014. Published December 2014. Originallyapproved in 1986. Last previous edition approved in 2009 as F1110 09. DOI:10.1520/F1110-09R14.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStand
15、ards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Society of Automotive Engineers (SAE), 400 CommonwealthDr., Warrendale, PA 15096-0001.4Available from Department of Defense Single Stock Point (DODSSP); http:/dodssp.daps.dla.milCopyright ASTM In
16、ternational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.4 Relative corrosion severity rating system:Appearance/Corrosion:0No visible corrosion and no discoloration present1Very slight corrosion or very slight discoloration, and/or up to 5 % of areaAcorroded
17、2Discoloration and/or up to 10 % of areaAcorroded3Discoloration and/or up to 25 % of areaAcorroded4Discoloration and/or more than 25 % of areaAcorroded, and/or pittingpresentA”Area” refers to area under the filter paper, or if no filter paper is used, the areawhere the test material was applied.6. I
18、nterferences6.1 It is possible that tap water containing large amounts ofdissolved solids, especially chlorides, will cause relative severecorrosion of the aluminum control panels. For this reason,reagent water is specified. For comparative purposes, a set ofaluminum test panels, with the locally av
19、ailable tap waterapplied to the filter paper, is sometimes run along with thereagent water panels.6.2 Filter paper made from glass fibers is not recommendedsince, in practice, corrosion of the control panels has often beenfound.7. Apparatus7.1 Humidity Test Cabinet, as specified in Test MethodD1748
20、or equal, capable of maintaining 95 to 100 % relativehumidity at 37.7 6 1C (100 6 2F).7.2 Oven, forced air circulation, capable of maintaining 37.76 1C (100 6 2F).7.3 Microscope, binocular, 10 to 40.8. Reagents and Materials8.1 Purity of WaterUnless otherwise indicated, referencesto water shall be u
21、nderstood to mean reagent water as definedby Specification D1193, Type IV.8.2 Aluminum Alloy Coupons:8.2.1 Aluminum alloy coupons shall conform to the follow-ing industry standards:SAE-AMS-QQ-A-250/4, 2024-T3 noncladSAE-AMS-QQ-A-250/5, 2024-T3 AlcladSAE-AMS-QQ-A-250/12, 7075-T6 noncladSAE-AMS-QQ-A-2
22、50/13, 7075-T6 Alclad8.2.2 Coupon SizeThe recommended coupon size 50 by100 by 1.0 to 1.5 mm (2 by 4 by 0.04 to 0.06 in.) has beenfound to provide suitable results for comparative tests. Smallersizes are not recommended, because of the increased variationsdue to edge effects. Larger coupons are accep
23、table, but thespace requirements for testing and storage shall be taken inconsideration.8.3 Unless otherwise specified, anodize the nonclad cou-pons in accordance with Military Specification MIL-A-8625,Type 1 (Chromic Acid) followed by a hot water seal.8.4 Filter PaperUse Whatman No. 5 or equal filt
24、er papermade from cellulose, 11 or 13 cm. Filter paper is not requiredwhen the material being tested is a solid. In case no filter paperis used, the area covered by the test material shall also beapproximately 25 by 75 mm (1 by 3 in.).9. Hazards9.1 The materials used for aircraft maintenance sometim
25、escontain flammable solvents, strong acids or alkalis, or othertoxic compounds.Take suitable precautions to prevent personalinjury from these hazards. When the composition of the testmaterial is not known, consult the manufacturer to determinewhether any hazards exist.9.2 Exercise special care in ha
26、ndling the chromic acidsolution, specified in 8.3, for its etching properties.10. Sampling10.1 Agitate or thoroughly mix the test material to assureuniformity. Where dilution of the material is required, usereagent water or the solvent specified by the product manufac-turer.Apply sufficient test mat
27、erial to saturate the area betweenthe metal coupons.11. Test Specimen11.1 Prepare three sets of test panels. A test panel set shallconsist of eight individual test coupons, sandwiched together inpairs of coupons of the same alloy and the same surfacetreatment, to provide four test coupon sandwiches
28、for each testcondition. Identify each coupon by impression stamping orother suitable permanent method.11.2 Clean the panels by solvent wiping, or vapor degreas-ing. Do not use acid or caustic cleaners. Remove ink stampedmarkings from the panels. Do not use abrasive materials toclean the panels.11.3
29、Prepare the test panel sets as follows for each alloy:11.3.1 One set for the compound to be tested at use dilution,11.3.2 One set for the compound to be tested in concen-trated form and11.3.3 One set for controls using reagent water.12. Preparation of Apparatus12.1 Verify that the humidity cabinet i
30、s operating at thespecified temperature and humidity.12.2 Verify that the oven is operating at the specifiedtemperature, with air circulation.13. Calibration and Standardization13.1 Since the test coupons include controls for comparativepurposes, no special calibration or standardization proceduresa
31、re required.14. Conditioning14.1 Conditioning of the test materials or the sets ofprepared test coupons is not required. Thoroughly agitate thetest sample before application to the test coupons.14.2 Allow the anodized panels to age for a period of atleast 48 h prior to exposure.15. Procedure15.1 Ass
32、emble the cleaned panels into three identicalgroups each having four different sets of panels suitablyF1110 09 (2014)2identified by permanent marking. Each panel set shall consistof two individual coupons of the same alloy and the samesurface treatment.15.2 Cut a piece of cellulose filter paper to a
33、pproximate 25by 75 mm (1 by 3 in.). Fit this piece over one of the coupons.Add the test solution at the use concentration to the paper untilsaturated. Cover the wet paper with the second coupon of thesandwich pair. Each sandwich shall be held together withwaterproof tape, with no more than a 25 mm (
34、1 in.) piece oftape, maximum width 20 mm (0.8 in.), on each of two oppositesides. Repeat the operation for each of the coupon sets in thegroup. This test may be omitted if the test material is to be usedin the concentrated form only. See 8.4 for deletion of the filterpaper.15.3 Prepare a second grou
35、p of panels as outlined in 15.2except apply the material to be treated in the concentratedas-received condition, without dilution by water or solvents.(Not applicable to dry granular materials.)15.4 Prepare a third group of panels, as outlined in 15.2,except apply reagent water only to the filter pa
36、per between thepanels.15.5 During each test day, expose the panels in the oven for8 h followed immediately by exposure in the humidity cabinet.Preferably start the alternating exposure periods on a Mondaymorning with the initial exposure in the oven. Over thefollowing weekend, the coupons are to be
37、left in the humiditycabinet. Maintain the humidity cabinet at 37.7 6 1C (100 62F) and 95 to 100 % relative humidity. Maintain the oven at37.7 6 2.8C (100 6 5F). Expose each set of panelsindividually, not stacked, in a horizontal position. Afterexposure, rinse the panels in warm tap water, and scrub
38、lightlywith a soft nonmetallic bristle brush. Rinse with reagent waterin accordance with Specification D1193, Type IV at roomtemperature. After drying, examine each panel under 10magnification, and rate each set according to the scale in 5.4.16. Interpretation of Results16.1 Compare the corrosion ra
39、ting on the set of panels fromthe first and second groups with those from the third, Reagentwater, control group.Any corrosion in excess of that shown bygroup 3 shall be cause for rejection. Give pitting corrosion ofany panel a severity rating of 4. Disregard any corrosion at theedges of the panel.
40、Compare only those surfaces which wereunder the filter paper, unless no filter paper has been used. Inthis case, the rating is to be determined on the areas which havebeen in direct contact with the test material. Pitting is definedin Guide G46.17. Report17.1 Prepare a report certifying that the tes
41、t has been run inaccordance with this test method and listing the exact condi-tions of the test as performed. Tabulate the corrosion rating ofall test panels used in the test, and state whether the testcompound is considered to be acceptable from a sandwichcorrosion standpoint.18. Precision and Bias
42、18.1 No statement is made about either the precision or biasof this test method since the result merely states whether thereis conformance to the criteria for success specified in theaccompanying material or process specification of the materialbeing tested, or both.19. Keywords19.1 aircraft mainten
43、ance chemicals; aluminum structuralaircraft alloys; faying surfaces; sandwich corrosionAPPENDIX(Nonmandatory Information)X1. RECOMMENDED PANEL IDENTIFICATION, TABULATION OF RESULTS, ANDEXPOSURE SCHEDULEX1.1 Panel Identification:X1.1.1 Test Material Diluted to Use Concentration:A-1 2024-T3 Nonclad An
44、odizedA-2 2024-T3 AlcladA-3 7075-T6 Nonclad AnodizedA-4 7075-T6 AlcladX1.1.2 Test Material in Concentrated, As-Received Condi-tion: B-1 2024-T3 Nonclad AnodizedB-2 2024-T3 AlcladB-3 7075-T6 Nonclad AnodizedB-4 7075-T36 AlcladX1.1.3 Specification D1193, Type IV Control: C-1 2024-T3Nonclad AnodizedC-2
45、 2024-T3 AlcladC-3 7075-T6 Nonclad AnodizedC-4 7075-T6 AlcladX1.2 Tabulation of Results:X1.2.1 See Fig. X1.1 for a recommended form for tabula-tion of results.X1.3 Exposure Schedule:X1.3.1 See Table X1.1 for a recommended exposure sched-ule.F1110 09 (2014)3ASTM International takes no position respec
46、ting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This sta
47、ndard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM Internati
48、onal Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below
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