ASTM_B_648_-_10_2015e1.pdf

Designation:B64810(Reapproved 2015)1Standard Test Method forIndentation Hardness of Aluminum Alloys by Means of aBarcol Impressor1This standard is issued under the fixed designation B648;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.1NOTEAppendix X1 was moved to appear one page in October 2015.1.Scope1.1 This test method covers the determination of indentationhardness of aluminum alloys using a Barcol Impressor,ModelNo.934-1.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.2.1 ExceptionThe values given in parentheses are forinformation only.NOTE1Another model,No.935,is for use on plastics but is notincluded in this test method and should not be used for aluminum alloys.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:2E6 Terminology Relating to Methods of Mechanical TestingE10 Test Method for Brinell Hardness of Metallic MaterialsE18 Test Methods for Rockwell Hardness of Metallic Ma-terialsE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 DefinitionsThe definitions of terms relating to hard-ness testing appearing in Terminology E6 shall be consideredas applying to the terms used in this test method.4.Significance and Use4.1 The Barcol Impressor is portable and therefore usefulfor in situ determination of the hardness of fabricated parts andindividual test specimens for production control purposes.4.2 This test method should be used only as cited inapplicable material specifications.5.Apparatus5.1 Barcol Impressor,Model 934-1 See Fig.1 and Fig.2.5.2 IndentorThe indentor shall consist of a hardened steeltruncated cone having an angle of 26 with a flat tip 0.157 mm(0.0062 in.)in diameter.It shall fit into a hollow spindle and beheld down by a spring-loaded plunger.See Fig.2.5.3 Indicating DeviceThe indicating dial shall have 100divisions,each representing a depth of 0.0076 mm(0.00030in.)penetration.The higher the reading,the harder the material.6.Test Parts or Specimen6.1 The testing area shall be smooth,clean,and free ofmechanical damage.The surface may be lightly polished toeliminate scratches or die lines.It shall be such that it can beessentially perpendicular to the indentor during the test.NOTE2The effect of curvature of the test specimen on the BarcolImpressor readings is presented in Appendix X1,Fig.X1.1.6.2 DimensionsTest parts or specimens shall be at least1.5 mm(116in.)thick and large enough to ensure a minimumdistance of 3 mm(18in.)in any direction from the indentorpoint to the edge.7.Calibration7.1 With the plunger upper guide backed out until it justengages the spring,place the impressor on a glass surface andpress down until the penetrator point is forced all the way backinto the lower plunger guide.The indicator should then read100 6 1.If it does not,loosen the locknut and turn the lowerplunger guide in or out to obtain a reading of 100.1This test method is under the jurisdiction of ASTM Committee B07 on LightMetals and Alloys and is the direct responsibility of Subcommittee B07.05 onTesting.Current edition approved Oct.1,2015.Published October 2015.Originallyapproved in 1978.Last previous edition approved in 2010 as B648 10.DOI:10.1520/B0648-10R15E01.2For 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 7.2 Read the hardness of a“hard”aluminum alloy referencedisk supplied by the manufacturer of the impressor and,ifnecessary,adjust so that the reading is within the range markedon the disk.7.3 Repeat the process with a“soft”reference disk.7.4 If the reference readings cannot be obtained,subsequentmeasurements are not valid.8.Procedure8.1 Support the test parts or specimens on a hard,firmsurface if they are likely to bend or deform under the pressureof the indentor(Note 3).The indentor must be perpendicular tothe surface being tested.NOTE3Curved surfaces may be more difficult to support.When theload is applied,bending and spring action in the part or specimen shouldbe avoided.8.2 Grasp the impressor firmly between leg and point sleeveand set both on the surface to be tested.For irregular parts