ASTM_C_633_-_13_2017.pdf

Designation:C63313(Reapproved 2017)Standard Test Method forAdhesion or Cohesion Strength of Thermal Spray Coatings1This standard is issued under the fixed designation C633;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 test method covers the determination of the degreeof adhesion(bonding strength)of a coating to a substrate or thecohesion strength of the coating in a tension normal to thesurface.The test consists of coating one face of a substratefixture,bonding this coating to the face of a loading fixture,andsubjecting this assembly of coating and fixtures to a tensileload normal to the plane of the coating.It is adapted particu-larly for testing coatings applied by thermal spray,which isdefined to include the combustion flame,plasma arc,two-wirearc,high-velocity oxygen fuel,and detonation processes forspraying feedstock,which may be in the form of,wire,rod,orpowder.NOTE1Thermal spray coating materials include ceramics,such asmetal oxides or carbides,and metals.In some cases,a coating is formedof different spray materials,such as an oxide layer sprayed onto a sprayedmetal-bonding layer.The substrate generally is a metal,but may be aceramic,such as an oxide or graphite.1.2 Usually this test method is performed at ambient tem-perature.Higher temperature testing is restricted by the needfor a suitable adhesive bonding agent.For certain fundamentalinvestigations,it is suggested that very low(cryogenic)tem-perature be used.1.3 This test method is limited to testing thermal spraycoatings that can be applied in thickness greater than 0.015 in.(0.38 mm).The limitation is imposed because an adhesivebonding agent is used in the test.Those bonding agentsestablished so far for this method tend to penetrate thermalspray coatings and may invalidate results unless the coatingsare thick enough to prevent penetration through the coating.Further development may establish that thin layers of certaintypes of especially dense coatings may be tested satisfactorily.Alternatively,new adhesive bonding agents that would allowreduction of the minimum thickness limitation may becomeavailable.1.4 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.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 and health limitations prior to use.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:2E4 Practices for Force Verification of Testing Machines3.Significance and Use3.1 This test method is recommended for quality control,acceptance testing;or it may help to develop or qualify athermal spray operators equipment and procedure or to aid indeveloping thermal spray coatings with improved adhesion andintegrity.3.2 This test method is useful for comparing adhesion orcohesion strengths of coatings of similar types of thermal spraymaterials.The test should not be considered to provide anintrinsic value for direct use in making calculations,such as todetermine if a coating will withstand specific environmentalstresses.Because of residual stresses in thermal spray coatings,actual strength depends upon the shape of the particular coatedpart.Also,in use,a coating may be stressed in a more complexmanner than is practical for a standard test.4.Apparatus4.1 A tension testing machine shall conform to the require-ments of Practices E4.The loads used in determining the1This test method is under the jurisdiction ofASTM Committee B08 on Metallicand Inorganic Coatings and is the direct responsibility of Subcommittee B08.12 onMaterials for Porcelain Enamel and Ceramic-Metal Systems.Current edition approved May 1,2017.Published May 2017.Originallyapproved in 1969.Last previous edition approved in 2013 as C633 01(2013).DOI:10.1520/C0633-13R17.2For 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 StatesThis international standard was developed in accordan