ASTM_D_3933_-_98_2017.pdf

Designation:D393398(Reapproved 2017)Standard Guide forPreparation of Aluminum Surfaces for Structural AdhesivesBonding(Phosphoric Acid Anodizing)1This standard is issued under the fixed designation D3933;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 indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This guide describes the requirements for phosphoricacid anodizing of aluminum and its alloys for structuraladhesive bonding.1.2 The procedure included herein is based on the commer-cial practice of numerous agencies and organizations.Themethod may be revised or supplemented,as necessary,toinclude methods based on proven performance.1.3 The surface preparation of metal systems used forqualification and quality-control testing of the adhesive shouldbe agreed upon between the manufacturer and the user.1.4 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.5 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.Aspecific precaution is given in 5.5.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D907 Terminology of AdhesivesD2651 Guide for Preparation of Metal Surfaces forAdhesiveBonding2.2 Federal Specifications:0-0-670 Orthophosphoric Acid,Technical33.Terminology3.1 DefinitionsMany terms in this guide are defined inTerminology D907.4.Significance and Use4.1 Durable adhesive bonds between metal to metal,metalto composites can be obtained reliably only through properselection and careful control of the materials used and the stepsin the bonding process.The preparation of the metallicsubstrates to obtain surfaces with appropriate characteristics isa critical step.Improper surface preparation can produceseemingly acceptable bonds that can degrade rapidly with time.This guide describes one method on how to properly preparealuminum surfaces can be obtained.4.2 The formation of reproducible,durable,adhesive bondsin structural assemblies requires great care in the selection ofmaterials,the preparation of the surfaces of the components tobe bonded,the fit of the components,and the performance ofthe steps in the bonding process.Experience has shown thatwhen adhesively bonded aluminum surfaces which have beenprepared in accordance with this guide produce relativelyreproducible,durable bonds.5.Apparatus5.1 Locate surface preparation and drying facilities separatefrom other activities or equipment,or both,to precludecontamination by substances detrimental to adhesion.5.2 Facilities should be arranged such that parts can flowfrom the beginning of surface preparation to the primingoperation without being touched.5.3 Filters or traps,or both,should be installed for removingairborne dust,moisture,and oil from all air lines or ducts usedfor solution agitation and parts drying.Periodically check,clean,or replace filters to ensure proper operation.1This guide is under the jurisdiction ofASTM Committee D14 on Adhesives andis the direct responsibility of Subcommittee D14.80 on Metal Bonding Adhesives.Current edition approved Nov.1,2017.Published November 2017.Originallyapproved in 1980.Last previous edition approved in 2010 as D3933 98(2010).DOI:10.1520/D3933-98R17.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3Available from U.S.Government Printing Office Superintendent of Documents,732 N.Capitol St.,NW,Mail Stop:SDE,Washington,DC 20401,http:/www.access.gpo.gov.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 5.4 Surface preparation facilities should not be used forpurposes other than the preparation of parts for adhesivebonding and subsequent finishing.5.5 Equipment requirements for this process include equip-ment normally used in the chemical processing of aluminumal