1、Designation: F 1110 02Standard Test Method forSandwich Corrosion Test1This standard is issued under the fixed designation F 1110; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses in
2、dicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test method defines the procedure for evaluatingthe corrosivity of aircr
3、aft 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 stated in SI units are
4、to be regarded as thestandard. The values given in parentheses are for information.1.3 This standard may involve hazardous materials, opera-tions, and equipment. This standard does not purport toaddress all of the safety concerns, if any, associated with itsuse. It is the responsibility of the user
5、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:D 1193 Specification for Reagent Water2D 1748 Test Method for Rust Pro
6、tection by Metal Preser-vatives in the Humidity Cabinet3G46 Guide for Examination and Evaluation of PittingCorrosion42.2 Industry Standards:5SAE-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, Plate and SheetSAE-A
7、MS-QQ-A-250/13 Al Alloy Alclad 7075, Plate andSheet2.3 Military Specification:MIL-A-8625 Anodic Coatings for Aluminum and Al Al-loys63. Terminology3.1 Definition of Term Specific to This Standard:3.1.1 sandwich corrosion testa comparative acceleratedenvironmental test of the corrosivity of liquid or
8、 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 the coupons.
9、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 solutions of dry gr
10、anularmaterial 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.5.2 Interpretati
11、on 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 testmaterial a
12、re 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 is rated 4exten
13、sive(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 approved Aug. 10
14、, 2002. Published September 2002. Originallypublished as F 1110 86. Last previous edition F 1110 90(1998).2Annual Book of ASTM Standards, Vol 11.01.3Annual Book of ASTM Standards, Vol 05.01.4Annual Book of ASTM Standards, Vol 03.02.5Available from Society of Automotive Engineers (SAE), 400 Commonwea
15、lthDr., Warrendale, PA 15096-0001.6Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700Robbins Ave., Philadelphia, PA 19111-5098, Attn: NPODS.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.4 Relative corrosi
16、on severity rating system:Appearance/Corrosion:0No visible corrosion and no discoloration present1Very slight corrosion or discoloration, and/or up to 5 % of areaAcorroded2Discoloration and/or up to 10 % of areaAcorroded3Discoloration and/or up to 25 % of areaAcorroded4Discoloration and/or more than
17、 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. Interferences6.1 It is possible that tap water containing large amounts ofdissolved solids, especially chlorides, will cause relat
18、ive severecorrosion of the aluminum control panels. For this reason,reagent water is specified. For comparative purposes, a set ofaluminum test panels, with the locally available tap waterapplied to the filter paper, is sometimes run along with thereagent water panels.6.2 Filter paper made from glas
19、s fibers is not recommendedsince, in practice, corrosion of the control panels has often beenfound.7. Apparatus7.1 Humidity Test Cabinet, as specified in Test MethodD 1748 or equal, capable of maintaining 95 to 100 % relativehumidity at 37.7 6 1C (100 6 2F).7.2 Oven, forced air circulation, capable
20、of maintaining 37.76 1C (100 6 2F).7.3 Microscope, binocular, 103 to 403.8. Reagents and Materials8.1 Purity of WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water as definedby Specification D 1193, Type IV.8.2 Aluminum Alloy Coupons:8.2.1 Aluminum alloy cou
21、pons 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-250/13, 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
22、beenfound to provide suitable results for comparative tests. Smallersizes are not recommended, because of the increased variationsdue to edge effects. Larger coupons are acceptable, but thespace requirements for testing and storage shall be taken inconsideration.8.3 Anodize the nonclad coupons in ac
23、cordance with Mili-tary Specification MIL-A-8625, Type 1 (Chromic Acid).8.4 Filter PaperUse Whatman No. 5 or equal filter 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 materia
24、l shall also beapproximately 25 by 75 mm (1 by 3 in.).9. Hazards9.1 The materials used for aircraft maintenance sometimescontain flammable solvents, strong acids or alkalis, or othertoxic compounds. Take suitable precautions to prevent personalinjury from these hazards. When the composition of the t
25、estmaterial is not known, consult the manufacturer to determinewhether any hazards exist.9.2 Exercise special care in handling 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 th
26、e material is required, usereagent water or the solvent specified by the product manufac-turer. Apply sufficient test material 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, sandwi
27、ched together inpairs of coupons of the same alloy and the same surfacetreatment, to provide four test coupon sandwiches 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 aci
28、d or caustic cleaners. Remove ink stampedmarkings from the panels. Do not use abrasive materials toclean the panels.11.3 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 fo
29、rm and11.3.3 One set for controls using reagent water.12. Preparation of Apparatus12.1 Verify that the humidity cabinet is operating at thespecified temperature and humidity.12.2 Verify that the oven is operating at the specifiedtemperature, with air circulation.13. Calibration and Standardization13
30、.1 Since the test coupons include controls for comparativepurposes, no special calibration or standardization proceduresare 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 th
31、e test coupons.14.2 Allow the anodized panels to age for a period of atleast 48 h prior to exposure.15. Procedure15.1 Assemble the cleaned panels into three identicalgroups each having four different sets of panels suitablyidentified by permanent marking. Each panel set shall consistof two individua
32、l coupons of the same alloy and the samesurface treatment.15.2 Cut a piece of cellulose filter paper to approximate 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 o
33、f theF1110022sandwich pair. Each sandwich shall be held together withwaterproof tape, with no more than a 25 mm (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 materi
34、al is to be usedin the concentrated form only. See 8.4 for deletion of the filterpaper.15.3 Prepare a second group 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 mate
35、rials.)15.4 Prepare a third group of panels, as outlined in 15.2,except apply reagent water only to the filter paper 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 pe
36、riods on a Mondaymorning with the initial exposure in the oven. Over thefollowing weekend, the coupons are to be 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 panelsi
37、ndividually, not stacked, in a horizontal position. After expo-sure, rinse the panels in warm tap water, and scrub lightly witha soft nonmetallic bristle brush. Rinse with reagent water inaccordance with Specification D 1193, Type IV at room tem-perature. After drying, examine each panel under 103 m
38、agni-fication, and rate each set according to the scale in 5.4.16. Interpretation of Results16.1 Compare the corrosion rating 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 fo
39、r rejection. Give pitting corrosion ofany panel a severity rating of 4. Disregard any corrosion at theedges of the panel. 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 dir
40、ect contact with the test material. Pitting is definedin Guide G46.17. Report17.1 Prepare a report certifying that the test 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, an
41、d state whether the testcompound is considered to be acceptable from a sandwichcorrosion standpoint.18. Precision and Bias18.1 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 i
42、n theaccompanying material or process specification of the materialbeing tested, or both.19. Keywords19.1 aircraft maintenance chemicals; aluminum structuralaircraft alloys; faying surfaces; sandwich corrosionAPPENDIX(Nonmandatory Information)X1. RECOMMENDED PANEL IDENTIFICATION, TABULATION OF RESUL
43、TS, ANDEXPOSURE SCHEDULEX1.1 Panel Identification:X1.1.1 Test Material Diluted to Use Concentration:A-1 2024-T3 Nonclad AnodizedA-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
44、-3 7075-T6 Nonclad AnodizedB-4 7075-T36 AlcladX1.1.3 Specification D 1193, Type IV Control:C-1 2024-T3 Nonclad AnodizedC-2 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 Sched
45、ule:X1.3.1 See Table X1.1 for a recommended exposure sched-ule.NOTE 1Record pitting corrosion separately, if present.AlloyCondition 1234ADilutedBConcentrateCSpecification D 1193, Type IVFIG. X1.1 Recommended Tabulation of ResultsF1110023ASTM International takes no position respecting the validity of
46、 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 standard is subject to
47、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 International Headquarters. Y
48、our 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.This standard is co
49、pyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).TABLE X1.1 Recommended Exposure ScheduleAStepExposure Time,Bh 612ConditionsTemperatureC (F)Relative Humidity, %1 8 37.7 (100) Ambient2 16 37.7 (100) 951003 8 37.7 (100) Ambient4 16 37.7 (100) 951005 8 37.7
