ASTM_D_3482_-_07a_2014.pdf

Designation:D348207a(Reapproved 2014)Standard Practice forDetermining Electrolytic Corrosion of Copper by Adhesives1This standard is issued under the fixed designation D3482;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.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This practice covers the determination of whether anadhesive has any corrosive effect on copper.It is ordinarilyintended to distinguish materials that might cause corrosion inelectrical and electronic equipment.This procedure is a sub-jective test for which precision and accuracy have not beenestablished.It is not recommended for adhesives on backing.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.3 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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D907 Terminology of AdhesivesD996 Terminology of Packaging and Distribution Environ-mentsE104 Practice for Maintaining Constant Relative Humidityby Means of Aqueous SolutionsG15 Terminology Relating to Corrosion and Corrosion Test-ing(Withdrawn 2010)33.Terminology3.1 DefinitionsDefinitions of terms in this test methodmay be found in Terminologies D907,D996,and G15.3.1.1 electrolytic corrosion,nthe corrosion of metal re-sulting from current flow under an electrical potential in thepresence of moisture.4.Summary of Practice4.1 Two parallel helices of fine copper wire are laid inetched grooves on a glass tube.The adhesive material is coatedover the wires and the tube and then allowed to set or cure.Thewired tube is exposed to high humidity with a d-c potentialapplied between the wires.Corrosion products are observedvisually.5.Significance and Use5.1 Adhesives can be exposed to both electrical potentialand humidity in many electrical and electronic applications.Itis therefore desirable to provide a means of examining thecorrosive tendencies of certain adhesives towards metals.5.2 Although electrolytic corrosion is a direct result of ionicconduction in the adhesive,the nature of the exposed metalswill have a bearing on both the severity of metal attack and thevisibility of corrosion products.Because it gives a visualindication of corrosion and because of its widespread use inelectrical circuits,copper is used in this practice.However,thiswould not preclude the use of other metals for specificinterests.5.3 This procedure is a subjective test in that determinationsof the presence of corrosion is based on a visual inspection fora green discoloration or other evidence of corrosion.6.Apparatus and Material6.1 Motor(Optional),low-speed,approximately 10 r/minfor winding wire helices.6.2 Oven(orTemperature-ControlledChamber),circulating-air,or chamber controlled at 39.5 6 1C(95 62F),unless otherwise specified.6.3 Battery,45-V,or equivalent source of d-c power.6.4 Corrosion Test ApparatusSee Fig.1.6.4.1 Helically Etched Glass TubingSee Fig.2.6.4.2 Wire,No.36 Awg,0.13 mm(0.005 in.)in diameter,OFHC(Oxygen-Free High-Conductivity)bare copper wire.1This practice is under the jurisdiction of ASTM Committee D14 on Adhesivesand is the direct responsibility of Subcommittee D14.80 on Metal BondingAdhesives.Current edition approved March 1,2014.Published March 2014.Originallyapproved in 1976.Last previous edition approved in 2007 as D3482 07a.DOI:10.1520/D3482-07AR14.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.4.3 Test Tube,borosilicate glass,32 mm(112in.)inoutside diameter,200 mm(8 in.)long.6.4.4 Rubber Stopper,No.6,neoprene.6.5 MiscellaneousSoldering iron,rosin-core solder,thinpolyethylene film,insulated wire,etc.7.Procedure7.1 Rinse a chemically cleaned helically etched glass tubewith distilled water and air dry.Keep clean until ready for use.7.2 Clean copper wire by immersing in fresh methyl ethylketone and wiping with clean,lint-free cloth.When materialsare cleaned,handle them only with clean white gloves,cleantongs,or other suitable implements.7.3 Attach the tube to the motor drive shaft and manuallylay the wire around the small knobs on the tube.Repeat withanother length of wire in the adjacent groove.Avoid e