1、Designation: E864 08E864 12Standard Practice forSurface Preparation of Aluminum Alloys to Be AdhesivelyBonded in Honeycomb Shelter Panels1This standard is issued under the fixed designation E864; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、of revision, the year of last revision. A number in 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 Department of Defense.1. Scope1.1 This practic
3、e covers the preparation of clean uniform surfaces of aluminum alloys suitable for formation of durable adhesivebonds to nonmetallic honeycomb materials in the manufacture of sandwich panels for tactical shelters.1.2 The values stated in SI units are to be regarded as the standard where only SI unit
4、s are given or where SI units are givenfirst followed by inch-pound units; where inch-pound units are given first followed by SI units, the inch-pound units are to regardedas the standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is
5、 the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. For a specific warning statement, see 5.2.16.2.1.2. Referenced Documents2.1 ASTM Standards:2D2674 Methods of Analysis of Sulfoch
6、romate Etch Solution Used in Surface Preparation of AluminumD3167 Test Method for Floating Roller Peel Resistance of AdhesivesE631 Terminology of Building ConstructionsE865 Specification for Structural Film Adhesives for Honeycomb Sandwich PanelsE866 Specification for Corrosion-Inhibiting Adhesive P
7、rimer for Aluminum Alloys to Be Adhesively Bonded in HoneycombShelter PanelsE1749 Terminology Relating to Rigid Wall Relocatable Shelters2.2 APHA Standard:3APHA Standard Methods for the Examination of Water and Waste Water (15th Edition, 1980), Sections 402, 403, and 4083. Terminology3.1 Definitions
8、See Terminologies E631 and E1749 for definitions of general terms used in this practice.4. Significance and Use4.1 Durable adhesive bonds to aluminum alloys can be obtained reliably only through proper selection and careful control ofthe materials used and the steps in the bonding process. The prepa
9、ration of the aluminum alloys to obtain clean, uniform surfaceswith appropriate characteristics is a critical step. This practice describes how such surfaces can be obtained.5. Apparatus5.1 General Processing:1 This practice is under the jurisdiction of ASTM Committee E06 on Performance of Buildings
10、 and is the direct responsibility of Subcommittee E06.53 on Materials andProcesses for Durable Rigidwall Relocatable Structures.Current edition approved Nov. 1, 2008Nov. 1, 2012. Published December 2008December 2012. Originally approved in 1982. Last previous edition approved in 20032008as E864 03.E
11、864 08. DOI: 10.1520/E0864-08.10.1520/E0864-12.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available fr
12、om the American Public Health Association (APHA), 800 I Street, NW, Washington, DC 20001-3710, http:/www.apha.org.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not
13、 be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Dr
14、ive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.1.1 All heated tanks shall be equipped with automatic temperature controls and shall have means for agitation to prevent localoverheating of the solution. Solutions may be heated by any internal or external means that do not change
15、their compositions.Steam shall not be introduced into any solution. Compressed air introduced into any solution or equipment shall have been filteredto remove oil and moisture.5.1.2 Tanks shall be made from, or lined with, materials that have no adverse effects on the solutions used or the parts bei
16、ngtreated. All tanks shall be of sufficient size to allow complete immersion of the largest part or assembly to be treated.5.2 Rinse TanksImmersion rinse tanks shall be equipped with a means for skimming or overflowing or both to remove surfacecontamination. The tanks shall be equipped with a means
17、for flushing hollow sections.5.3 RinsesRinses, other than final rinses, shall be maintained in such a manner to prevent carryover of materials that wouldadversely affect the next solution (for example, using a fog water rinse as the aluminum part/assembly is being withdrawn fromthe rinse tank).6. Ma
18、terials6.1 WaterWater used for makeup of processing solutions and final rinsing shall be deionized water or shall meet therequirement of Table 1.Analyses shall be performed as often as necessary to assure that the water meets the requirements. Samplesfor analysis shall be collected at the processing
19、 tanks.6.2 Etch Solution:6.2.1 Method I, Sulfo-Chromate Etch (FPL)The chemical analysis of the etch solution shall be maintained at approximately30 parts by mass of water, ten parts by mass of sulfuric acid (sp gr 1.84), and one to four parts by mass of sodium dichromate.Prior to use, a minimum of 0
20、.06 part by mass of dissolved 2024 aluminum shall be added. (WarningIt is recognized thatchromates present a hazard to health. Use and disposal procedures are governed by Federal and Local EPA and DER limitations.)6.2.2 Method II, Sulfo-Ferric Etch (P2)The chemical analysis of the etch solution shal
21、l be maintained at approximately 27 to36 % by weight of sulfuric acid (sp gr 1.84) and 2.9 to 4.7 oz/gal of ferric iron or 18 to 22 oz/gal of ferric sulfate. This is theequivalent of 2 gal of concentrated sulfuric acid and 12.5 lb of ferric sulfate in every 10 gal of solution. Two gallons of a 50 %f
22、erric sulfate solution may be used in place of the 12.5 lb of the powdered ferric sulfate.NOTE 1Only virgin ferric sulfate solution shall be used in this process. Impurities in reclaimed ferric sulfate will cause unwanted reactions when thealuminum is treated.6.3 Alkaline Cleaning SolutionNonetch, a
23、lkaline cleaning solution shall be prepared in accordance with the manufacturersrecommendations, or as indicated in 7.1.28.1.2. When the aluminum being cleaned is immersed in the alkaline cleaner for the timeand at the temperature used for processing, there shall be no evidence of gas evolution, etc
24、hing, or metal removal. The alkalinesolution shall not contain silicates.6.4 Quality Assurance AdhesiveThe adhesive system used for the quality assurance tests of 8.69.6 shall meet SpecificationE865. The adhesive shall be changed only when a batch is almost exhausted so the results of any particular
25、 days testing can bedirectly compared to the results of previous tests. When a change is made in the batch or lot of adhesive used, an additional setof tests shall be made to compare the old batch or lot with the new one to establish a basis for comparison between the resultsobtained with each.7. Te
26、st Methods7.1 Chemical AnalysesPerform chemical analyses of the water and solutions as indicated in 6.27.2 and 6.37.3. Analyze asoften as necessary to maintain the required concentrations at a minimum of every day of operation. If a process is not in use duringthe normal analysis period, note this o
27、n the analysis record and analyze the solution prior to further use.7.2 Water AnalysesAnalyze as described in APHA Standard Methods for the Examination of Water and Waste Water.7.3 Etch Solution Analysis:7.3.1 Sulfo-Chromate EtchPerform the analyses in accordance with Methods D2674.7.3.2 Sulfo-Ferri
28、c EtchPerform the analyses in accordance with 6.3.2.17.3.2.1 and 6.3.2.27.3.2.2.TABLE 1 Requirements for Water to Be Used in Solutions andRinsesRequirementsMin MaxpH 6.0 8.0Total solids, ppm . 200Total alkalinity as CaCO3, ppm . 125Chloride content, ppm . 15E864 1227.3.2.1 Sulfuric AcidPipet a 1-mL
29、(0.03-oz) sample into a 250-mL (8.5-oz) Erlenmeyer flask containing 100 mL (3.4 oz) ofdistilled water. Add 1 g (0.03 oz) of tribasic sodium citrate and 1 g (0.03 oz) of sodium fluoride. Add 2 to 3 drops ofphenolphthalein indicator. Titrate with 0.4 N sodium hydroxide to clear or faint pink. Calculat
30、e the normality of sulfuric acid inaccordance with Table 2.7.3.2.2 Ferric IonPipet a 2-mL (0.06-oz) sample into a 250-mL (8.5-oz) Erlenmeyer flask containing 100 mL (3.4 oz) ofdistilled water. Add 10 mL (0.3 oz) of concentrated hydrochloric acid. Add 1 to 2 g (0.03 to 0.06 oz) of potassium iodide ti
31、tratewith 0.10 N sodium thiosulfate to a greenish color.Add about 2 mLof starch solution. Continue titration to a clear green end point.Calculate ferric sulfate as follows:mL sodium thiosulfate used32.795g/Lferric ion (1)7.4 Visual InspectionInspect parts visually for stains and water break.7.5 Floa
32、ting Roller Peel TestTest in accordance with Test Method D3167.8. Procedure8.1 Surface PreparationPerform the steps of the procedure in accordance with 7.1.1-8.1.1-7.1.58.1.5 and Table 3 or Table 4as appropriate. Observe the restrictions listed in 7.28.2.8.1.1 PrecleaningRemove visible oil and greas
33、e from the aluminum by vapor degreasing, solvent cleaning, or other suitablemethod to ensure a clean, nonoily surface.8.1.2 Alkaline CleaningImmerse the aluminum in the alkaline cleaning solution held from 50 to 80C (122 to 176F) for aminimum of 5 min. Follow the alkaline cleaning by thoroughly rins
34、ing in water from room temperature to 70C (158F). Whenthe immersion does not completely clean the aluminum, alkaline cleaning shall be repeated. Keep the parts wet between thealkaline treatment and immersion in the rinse tank.8.1.3 Etching:8.1.3.1 Sulfo-Chromate EtchImmerse the aluminum parts in the
35、 etch solution for 9 to 15 min from 65 to 70C (149 to 158F).Keep the parts wet between the etch tank and the rinse tank. Follow the etching by thoroughly rinsing with room temperature water.8.1.3.2 Sulfo-Ferric EtchImmerse the aluminum parts in the etch solution for 10 to 20 min from 49 to 65C (120
36、to 149F).Immerse the flat sheet for 10 to 12 min. Extrusions may require up to 20 min. Keep the parts wet between the etch tank and therinse tank. Follow the etching by thoroughly rinsing in water at 55C (131F) maximum.8.1.4 Final RinseRinse the aluminum for 1 to 2 min in water from room temperature
37、 to 55C (131F). Check parts that canbe readily observed for water break and recycle if a water break occurs. Verify the water break-free surface for 30 s. If the waterfilm does not remain continuous for 30 s, repeat surface preparation procedure (see 7.1.4.18.1.4.1).NOTE 2A water break-free surface
38、maintains a continuous water film (no beads) for a period of at least 30 s after being sprayed or immersion rinsedin clean water at a temperature below 38C (100F).8.1.4.1 ReworkParts that are rerun, because of water break, stains, or unprimed parts that have exceeded the permitted storagetime shall
39、be reworked no more than two times. Do not exceed a total immersion time of 34 min.8.1.5 DryingAir dry the aluminum for not more than 1 h at a temperature not exceeding 65C (149F) prior to movement tothe controlled area.8.2 Restrictions:8.2.1 Immerse parts completely in all solutions.8.2.2 Do not al
40、low rinsing stains and dichromate stains on the bonding surfaces.8.2.3 Place cleaned dried parts within 12 h in a controlled area with filtered air that is maintained at a relative humidity of 50 %maximum. Prime or bond the cleaned parts within 16 h.8.2.4 Do not allow the solution temperature to exc
41、eed 63C (145F) when changing a new sulfo-ferric etch tank.TABLE 2 Calculation of Normality of Sulfuric Acid to Percent byWeight (1 g/100 g)NOTE 1N sulfuric acid = mL 0.4 N NaOH 0.4N % N %4.65 = 20 7.76 = 314.91 = 21 8.06 = 325.18 = 22 8.37 = 335.45 = 23 8.68 = 345.73 = 24 8.99 = 356.01 = 25 9.31 = 3
42、66.29 = 26 9.64 = 376.58 = 27 9.96 = 386.86 = 28 10.3 = 397.16 = 29 10.6 = 407.46 = 30E864 1238.2.5 Take precautions to prevent precipitation (keep spent solution warm in transport) when taking spent sulfo-ferric etchsolution to a waste disposal facility.9. Quality Assurance9.1 HandlingParts that ha
43、ve been processed shall be handled using clean cotton gloves.TABLE 3 Procedure for Surface Preparation of Aluminum AlloysUsing the Sulfuric Acid-Sodium Dichromate EtchSTEP 1PRECLEAN (see 7.1.1)STEP 1PRECLEAN (see 8.1.1)Vapor degrease or clean with safety solvent. Flush all hollow sections.Repeat as
44、necessary.STEP 2ALKALINE CLEAN (see 7.1.2)STEP 2ALKALINE CLEAN (see 8.1.2)Immerse in aluminum cleaner from 50 to 80C (122 to 176F) for 5 to 10 min.Repeat as necessary.STEP 3RINSE (see 7.1.2)STEP 3RINSE (see 8.1.2)Use water from room temperature to 70C (158F).STEP 4ETCH (see 7.1.3.1)STEP 4ETCH (see 8
45、.1.3.1)Immerse in sulfuric acid-sodium dichromate etch for 9 to 15 min from 65 to70C (149 to 158F). Spray rinse heavy sections as they emerge from thesolution as necessary to prevent staining.STEP 5RINSE (see 7.1.3.1)STEP 5RINSE (see 8.1.3.1)Use room temperature water.STEP 6FINAL RINSE (see 7.1.4)ST
46、EP 6FINAL RINSE (see 8.1.4)Use water from room temperature to 50C (122F) for 1 to 2 min.STEP 7DRY (see 7.1.5)STEP 7DRY (see 8.1.5)Use air from room temperature to 65C (149F) for not more than 1 h.TABLE 4 Procedure for Surface Preparation of Aluminum AlloysUsing the Sulfo-Ferric EtchSTEP 1PRECLEAN (s
47、ee 7.1.1)STEP 1PRECLEAN (see 8.1.1)Vapor degrease or clean with safety solvent. Flush all hollow sections.Repeat as necessary.STEP 2ALKALINE CLEAN (see 7.1.2)STEP 2ALKALINE CLEAN (see 8.1.2)Immerse in aluminum cleaner at 50 to 80C (122 to 176F) for 5 to 10 min.Repeat as necessary.STEP 3RINSE (see 7.
48、1.2)STEP 3RINSE (see 8.1.2)Use water from room temperature to 70C (158F).STEP 4ETCH (see 7.1.3.2)STEP 4ETCH (see 8.1.3.2)Immerse in the sulfo-ferric etch for 1020 min from 49 to 65C (120 to149F). Spray rinse heavy sections as they emerge from the solution asnecessary to prevent staining.STEP 5RINSE
49、(see 7.1.3.2)STEP 5RINSE (see 8.1.3.2)Rinse for 2 min. minimum in water at 55C (131F) maximumSTEP 6FINAL RINSE (see 7.1.4)STEP 6FINAL RINSE (see 8.1.4)Use water from room temperature to 55C (131F) for 1 to 2 min.STEP 7DRY (see 7.1.5)STEP 7DRY (see 8.1.5)Use air from room temperature to 65C (149F) for not more than 1 h.E864 1249.2 Marking and StoringAll processed parts shall be marked with the date or time of processing, or both. The processed partsshall not be marked on t
