ASTM_B_896_-_10_2015.pdf

Designation:B89610(Reapproved 2015)Standard Test Methods forEvaluating Connectability Characteristics of ElectricalConductor Materials1This standard is issued under the fixed designation B896;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 These test methods define procedures for the relativecharacterization of conductor material connectability on thebasis of measurements of parameters important to the designand performance of electrical contacts and connections to andwith such conductors for both power and signal applications.1.2 The parameters measured are contact resistance as afunction of contact force,fretting sensitivity,and compressiverelaxation.1.3 Provision is made for measurement of the connectabilityparameters at elevated temperature,or corrosive ambient,orboth,as may be required for evaluation for particular applica-tions.1.4 These test methods,using standardized specimen geom-etry and procedures,are applicable to conductor materials asemployed in an electrical system and may be adapted forevaluation of connectability of materials in the form of actualconnection system components.1.5 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.6 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 become familiarwith all hazards including those identified in the appropriateSafety Data Sheet(SDS)for this product/material as providedby the manufacturer,to establish appropriate safety and healthpractices,and determine the applicability of regulatory limi-tations prior to use.2.Referenced Documents2.1 ASTM Standards:2B539 Test Methods for Measuring Resistance of ElectricalConnections(Static Contacts)B542 Terminology Relating to Electrical Contacts and TheirUse3.Terminology3.1 DefinitionsDefinitions of terms used in this testmethod are in accordance with Terminology B542.3.2 Definitions of Terms Specific to This Standard:3.2.1 connectability,na combination of properties deter-mining the ability of a material to establish and maintain stablelow resistance electrical contact under the influence of dete-riorating environmental and operational factors.3.2.2 fretting,naccelerated surface damage occurring atthe interface of contacting materials subjected to small oscil-latory displacements.4.Summary of Test Method4.1 Contact ResistanceContact resistance is measured asforce is increased between conductors in a crossed-rod contactpair of the material(s)being tested.Held at the maximumspecified force,test contacts may be exposed to temperaturechanges or corrosive environments such as high humidity toobserve the effects of such conditions on electrical contactresistance.4.2 Fretting SensitivityContact resistance of a crossed-rodpair is measured at constant normal force while a microscopicoscillitory tangential motion is applied at the contact interface.The number of applied motion cycles required to inducecontact resistance instability is determined.The test may beperformed at elevated temperature or in corrosive environment.1These test methods are under the jurisdiction of ASTM Committee B02 onNonferrous Metals and Alloys and are the direct responsibility of SubcommitteeB02.11 on Electrical Contact Test Methods.Current edition approved Oct.1,2015.Published October 2015.Originallyapproved in 1999.Last previous edition approved in 2010 as B896 101.DOI:10.1520/B0896-10R15.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.3 Compressive RelaxationChange of applied contactforce with time,at fixed engagement displacement of crossed-wire specimens,is measured.The test may be performed atelevated temperature.5.Significance and Use5.1 These test methods develop comparative informationuseful for the design of stationary contacts for wire,cable,andother conductors.5.2 These test methods produce results,which are free of theinfluence of arbitrary connection systems.5.3 The influence of conductor surface pretreatments andplatings can be evaluated by these test methods.5.4 The influence of environmental factors,such as hightemperature and corrosive environment can be evaluated bythese test methods.5.5 The results obtained by these test methods provideguidance on connection system design parameters,such ascontact force and gas tightness requirements.6.Test Methods6.1 These test methods provide for standardization of speci-me