1、Designation: E1826 11E1826 12Standard Specification forLow Volatile Organic Compound (VOC) Corrosion-InhibitingAdhesive Primer for Aluminum Alloys to Be AdhesivelyBonded1This standard is issued under the fixed designation E1826; the number immediately following the designation indicates the year ofo
2、riginal adoption or, in the case 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
3、 Defense.1. Scope1.1 This specification covers pigmented, sprayable, low volatile organic compound (VOC) corrosion-inhibiting adhesiveprimers for use on aluminum alloys that are to be adhesively bonded in the fabrication of panels for tactical shelters. When appliedto a properly prepared surface of
4、aluminum alloy, the primer imparts corrosion resistance and forms a surface suitable for structuralbonding and for coating with shelter paint finishes.1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversionsto inch-pound units tha
5、t are provided for information only and are not considered standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the a
6、pplicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2B117 Practice for Operating Salt Spray (Fog) ApparatusB209 Specification for Aluminum and Aluminum-Alloy Sheet and PlateD1002 Test Method for Apparent Shear Strength of Single-Lap-Joint Adhesively Bonded Me
7、tal Specimens by Tension Loading(Metal-to-Metal)D3167 Test Method for Floating Roller Peel Resistance of AdhesivesE631 Terminology of Building ConstructionsE864 Practice for Surface Preparation of Aluminum Alloys to Be Adhesively Bonded in Honeycomb Shelter PanelsE865 Specification for Structural Fi
8、lm Adhesives for Honeycomb Sandwich PanelsE874 Practice for Adhesive Bonding of Aluminum Facings to Nonmetallic Honeycomb Core for Shelter PanelsE1749 Terminology Relating to Rigid Wall Relocatable Shelters2.2 Federal Specifications:3QQ-A-250/8d Aluminum Alloy 5052 H34 Plate and SheetQQ-A-250/11d Al
9、uminum Alloy 6061 T6 Plate and Sheet2.3 Government Document:4Rule 1124 Aerospace Assembly and Component Manufacturing Operations, South Coast Air Quality Management District3. Terminology3.1 DefinitionsSee Terminologies E631 and E1749 for definitions of general terms used in this specification.1 Thi
10、s specification is under the jurisdiction of ASTM Committee E06 on Performance of Buildings and is the direct responsibility of Subcommittee E06.53 on Materialsand Processes for Durable Rigidwall Relocatable Structures.Current edition approved May 1, 2011Nov. 1, 2012. Published May 2011 December 201
11、2. Originally approved in 1996. Last previous edition approved in 20052011 asE1826 05.E1826 11. DOI: 10.1520/E1826-11.10.1520/E1826-2.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume infor
12、mation, refer to the standards Document Summary page on the ASTM website.3 Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/dodssp.daps.dla.mil.4 Available from South Coast Air Quality Management District, 21865 Cop
13、ley Dr. Diamond Bar, CA 91765, http:/www.aqmd.gov.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 be technically possible to adequately depict all changes accura
14、tely, 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 Drive, PO Box C700, West Conshohocken, PA 19428-2959. United State
15、s14. Materials and Manufacturer4.1 The primer shall be a pigmented liquid composed of a modified epoxy phenolic or other resin system compounded to bespray-applied to produce a continuous, uniform coating without dilution.5. Physical Properties5.1 The uncured primer shall be tested as specified in 5
16、.16.1 and meet the requirement of Table 1.5.2 Properties of Cured FilmWhen applied and cured in accordance with 5.1.86.1.8, the cured film shall meet therequirements of Tables 2 and 3 when tested as specified in 5.26.2 and 5.36.3.5.3 Storage StabilityPrimer stored in accordance with 5.1.36.1.3 shall
17、 meet the requirements for normal- and low-temperaturefloating roller peel in Table 3 when cured in accordance with 5.1.86.1.8 and tested as specified in 5.3.76.3.7 and 5.3.86.3.8.5.4 Shelf LifeThe shelf life of the primer at 25 6 7C (77 6 12F) shall be at least four days. After four days, when test
18、edaccording to 5.1.46.1.4, the primer shall meet the requirements for normal- and low-temperature floating roller peel in Table 3when cured in accordance with 5.1.86.1.8 and tested as specified in 5.3.76.3.7 and 5.3.86.3.8.5.5 Film ThicknessThe average, minimum, and maximum film thicknesses shall be
19、 between 0.0025 and 0.010 mm (0.0001and 0.0004 in.) 615 % coefficient of variation. At least five thickness readings shall be made with no more than one in any 645mm2 (1 in.2) area.5.6 VOC ContentThe volatile organic compound (VOC) is any volatile compound containing the element of carbon,excluding
20、methane, carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates, and ammonium carbonates,as stated in Rule 1124. The VOC content shall meet the requirement in Table 1 when determined in accordance with 5.1.96.1.9.6. Test Methods6.1 Uncured Primer:6.1.1 Solids ContentDetermin
21、e the solids content by heating a 2-g sample of thoroughly mixed primer in an ignition-losscrucible with cover at 121 6 5C (250 6 9F) for not less than 90 min. Cool the crucible to room temperature in a desiccator.Weighings before and after heating shall be accurate to 60.001 g. Calculate the mass o
22、f solids remaining as a percentage of theinitial sample mass as follows:Percent solids content5mass of nonvolatile residueinitial sample mass 3100 (1)6.1.2 Ash ContentPlace the crucibles containing the solids content samples in a furnace at 565 6 28C (1050 6 82F) fornot less than 60 min. Cool the cr
23、ucible to room temperature in a desiccator. Weighings before and after heating shall be accurateto 60.001 g. Calculate the ash content remaining as a percentage of the solids content as follows:Percent ash content5 mass of ash residuemass of nonvolatile residue3100 (2)6.1.3 Storage StabilityStore a
24、sample of the primer for three months from the date of manufacture at a temperaturerecommended by the manufacturer. The stored sample shall meet the requirements for normal- and low-temperature floating rollerpeel in Table 3 when cured in accordance with 5.1.86.1.8 and tested as specified in 5.3.76.
25、3.7 and 5.3.86.3.8.6.1.4 Shelf LifeStore a sample of the primer for four days at 25 6 7C (77 6 13F). The aged sample shall meet therequirements for normal- and low-temperature floating roller peel in Table 3 when cured in accordance with 5.1.86.1.8 and testedas specified in 5.3.76.3.7 and 5.3.86.3.8
26、.6.1.5 Film ThicknessThe cured primer film thickness shall be determined with a eddy-current instrument as specified in5.2.26.2.2.6.1.6 ColorDuring spray application, there shall be a discernible color change for the primer thickness specified in 4.55.5.TABLE 1 Physical Properties of Uncured Liquid
27、PolymerTest RequirementSolids content,% Report onlyAsh content, % Report onlyColor Easily visible filmVOC content 250 g/L maxTABLE 1 Physical Properties of Uncured Liquid PolymerTest RequirementSolids content,% Report onlyAsh content, % Report onlyColor Easily visible filmVOC content 250 g/L maxE182
28、6 1226.1.7 SprayabilityThe primer shall be capable of being readily applied in accordance with the manufacturers instructions toall test panels of either 6061 T6 or 5052 H34 aluminum alloy (Fed. Spec. QQ-A-250/11d or QQ-A-250/8d, respectively, orSpecification B209) and cleaned in accordance with Pra
29、ctice E864 for each of the tests described in 5.1.8-6.1.8-5.3.86.3.8.6.1.8 Curing PropertiesTest the cured film for the ability to meet the requirements listed in Tables 2 and 3. Spray the primeronto the test panels and air dry at least 20 min at 24 6 5C (77 6 9F); then heat in air for 65 6 5 min at
30、 121 6 5C (250 69F).6.1.9 VOC ContentThe grams of VOC per litre of primer, less water and exempt compounds per Rule 1124, shall bedetermined by the adhesive primer manufacturer in accordance with Rule 1124 and meet the requirement for VOC content in Table1.6.2 Cured Film:6.2.1 Test Panels and Panel
31、PreparationTest panels shall be either 6061 T6 or 5052 H34 bare aluminum alloy (Fed. Spec.QQ-A-250/11d or QQ-A-250/8d, respectively, or Specification B209) and cleaned in accordance with Practice E864.6.2.2 Smooth Uniform CoatingClean a 30- by 30-cm (12- by 12-in.) panel, spray to a primer thickness
32、 as specified in 4.55.5,and cure as specified in 5.1.86.1.8. Determine the primer thickness with a Fisher isoscope MP2-T3.3B (or equivalent) calibratedwith standards between 0.0025 and 0.010 mm (0.0001 and 0.0004 in.). The primer thickness shall meet the requirements in 4.55.5and Table 2.6.2.3 Penci
33、l HardnessDetermine the pencil hardness of the cured film using the following procedure:6.2.3.1 Preparation of PencilsPrepare a set of drawing pencils ranging in hardness from 6B to 5H by stripping the wood awayfrom the end approximately 10 mm (38 in.) without damaging the lead. Square the tip of th
34、e lead by holding the pencil in a verticalposition and moving the lead back and forth over 400-grit or finer abrasive paper. Square the tip of the lead after each trial.6.2.3.2 ProcedurePlace a test panel with the cured primer applied in a horizontal position. Push pencils of increasing hardnessat a
35、 45 angle into the coated surface of the panel until one is found that will cut or scratch the coating. Use the number of thispencil to express the primer hardness.6.2.4 Environmental Resistance TestClean three test panels for each test described in 5.2.5-6.2.5-5.2.76.2.7 approximately 76by 127 mm (
36、3 by 5 in.) in accordance with 5.2.16.2.1. Apply the primer and cure in accordance with 4.55.5 and 5.1.86.1.8. Theprimed panels shall be subjected to the environments specified in 5.2.5-6.2.5-5.2.76.2.7 and there shall be no cracking, noblistering, and a minimum pencil hardness of 4H.TABLE 2 Physica
37、l Property of Cured Film on Primed SurfacesTest RequirementSmooth uniform coating 0.0025 to 0.010 mm (0.0001 to 0.0004in.) 15 % coefficient of variationTABLE 2 Physical Property of Cured Film on Primed SurfacesTest RequirementSmooth uniform coating 0.0025 to 0.010 mm (0.0001 to 0.0004in.) 15 % coeff
38、icient of variationTABLE 3 Physical Properties of Bonded SpecimensTest Requirements(min)Normal-temperature lap shear, 24C (77F), MPa (psi) 20.0 (2903)Low-temperature lap shear, 55C (67F), MPa (psi) 20.0 (2903)High-temperature lap shear, 93C (200F), MPa (psi) 13.0 (1890)Humidity exposure lap shear, 9
39、3C (200F), MPa (psi) 8.0 (1161)Salt spray exposure lap shear, 35C (95F), MPa (psi) 16.0 (2322)Normal-temperature floating roller peel strength, 24C (75F),N/m (lbf/in.)4400 (25.1)Low-temperature floating roller peel strength, 55C (67F),N/m (lbf/in.)2625 (15.0)TABLE 3 Physical Properties of Bonded Spe
40、cimensTest Requirements(min)Normal-temperature lap shear, 24C (77F), MPa (psi) 20.0 (2903)Low-temperature lap shear, 55C (67F), MPa (psi) 20.0 (2903)High-temperature lap shear, 93C (200F), MPa (psi) 13.0 (1890)Humidity exposure lap shear, 93C (200F), MPa (psi) 8.0 (1161)Salt spray exposure lap shear
41、, 35C (95F), MPa (psi) 16.0 (2322)Normal-temperature floating roller peel strength, 24C (75F),N/m (lbf/in.)4400 (25.1)Low-temperature floating roller peel strength, 55C (67F),N/m (lbf/in.)2625 (15.0)E1826 1236.2.5 Water ResistanceImmerse the panels with the cured primer coating in distilled water fo
42、r seven days at 24 6 3C (756 5F) and then expose to 95 to 100 % relative humidity at 50 6 3C (121 6 5F) for 30 days. After exposure the panels shallmeet the requirements in 5.2.46.2.4, and there shall be no loss of adhesion as described in 5.2.86.2.8.6.2.6 Heat ResistanceHeat test panels prepared as
43、 in 5.2.46.2.4 at 12063C (24865F) for 70 h.After exposure the panelsshall meet the requirements in 5.2.46.2.4, and there shall be no loss of adhesion as described in 5.2.86.2.8.6.2.7 Corrosion ResistanceScribe test panels prepared in accordance with 5.2.46.2.4 through the coating to the base metalwi
44、th two diagonal scribe marks extending from corner to corner and then expose them to 5 % salt fog in accordance with PracticeB117 for 40 days. After exposure the panels shall meet the requirements in 5.2.46.2.4, and there shall be no undercutting of theprimer along the scribe lines.blistering, crack
45、ing or substrate degradation more than 3 mm from scribe mark.6.2.8 Loss of Adhesion:6.2.8.1 Thoroughly dry the panel by wiping with a clean dry cheesecloth. Conduct the test at 20 to 27C (68 to 81F).6.2.8.2 Scribe two parallel scratches 25 mm (1 in.) apart through the coating down to the metal with
46、a sharp edged scribe.6.2.8.3 Apply a strip of 25-mm (1-in.) wide masking tape (not more than five months old from date of manufacture) across thescratches at 90 to the scribe lines in the panel area to be tested. Press the tape down using two passes of a 2-kg (4.4-lb)rubber-covered roller approximat
47、ely 90 mm (3.5 in.) in diameter by 44.5 mm (1.75 in.) in width. The durometer of the rollersurface shall be 70 to 80 Shore A.6.2.8.4 As an alternative to 5.2.8.36.2.8.3, the tape shall be pressed down by rolling the tape roll along the strip of applied tapeusing a firm hand pressure of approximately
48、 2 kg (4.4 lb).6.2.8.5 Remove the tape in one abrupt motion perpendicular to the panel. No primer shall be removed from the panel, other thanthat previously removed during the scribing procedure in 5.2.8.26.2.8.2.6.3 Bonding Property Tests:6.3.1 Preparation of Test SpecimensPrepare five specimens in
49、 accordance with Practice E864 for each of the tests in Table3. The lap shear specimens shall be in accordance with Test Method D1002 and the peel specimens in accordance with Test MethodD3167. The adherents shall be of either 6061 T6 or 5052 H34 aluminum alloy (Fed. Spec. QQ-A-250/11d or QQ-A-250/8d,respectively, or Specification B209).Apply the primer and allow to air dry for not less than 20 min at 2565C (7869F); followby heating at 121 6 5C (250 6 9F) for 65 6 5 min. Bond and cure
