ASTM_B_527_-_15.pdf

Designation:B52715Standard Test Method forTap Density of Metal Powders and Compounds1This standard is issued under the fixed designation B527;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.Scope*1.1 This test method specifies a method for the determina-tion of tap density(packed density)of metal powders andcompounds,that is,the density of a powder that has beentapped,to settle contents,in a container under specifiedconditions.1.2 With the exception of the values for density and themass used to determine density,for which the use of the gramper cubic centimetre(g/cm3)and gram(g)units is the long-standing industry practice,the values in SI units are to beregarded as standard.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:2B215 Practices for Sampling Metal PowdersB243 Terminology of Powder MetallurgyE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE456 Terminology Relating to Quality and StatisticsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 Definitions of Terms Specific to This Standard:Termsused in this test method are defined in B243.4.Significance and Use4.1 This test method covers the evaluation of the tap densityphysical characteristic of metal powders and related com-pounds.The degree of correlation between the results of thistest method and the quality of powders in use will vary witheach particular application and has not been fully determined.5.Apparatus5.1 Balance,of appropriate capacity to satisfy the require-ments shown in Table 1 and accuracy of 6 0.05 g.5.2 Graduated Glass Cylinder,calibrated to contain 100cm3at 20 C,the height of the graduated portion beingapproximately 175 mm.The graduations shall be at 1 cm3intervals,thus allowing a measuring accuracy of 60.5 cm3.Forapparent densities over 4 g/cm3,do not use the 100 cm3cylinder,see section 5.2.1.1.5.2.1 Alternatively,the following may be used:5.2.1.1 Graduated Glass Cylinder,calibrated to contain 25cm3at 20 C,the height of the graduated portion beingapproximately 135 mm.The graduations shall be at 0.2 cm3intervals,thus allowing a measuring accuracy of 60.1 cm3.5.2.1.2 A 25 cm3cylinder shall be used for powders ofapparent density higher than 4 g/cm3,in particular for refrac-tory metal powders.5.3 Tapping Apparatus,which permits the tapping of thegraduated cylinder against a firm base.The tapping shall besuch that a densification of the powder can take place withoutany loosening of its surface layers.The stroke shall be 3 mmand the tapping frequency shall be between 100 and 300taps/min.An example of a tapping apparatus is shown in Fig.1.6.Test Specimen6.1 For the quantities of powder required for each test,seeTable 1.Obtain test portions according to Practices B215.6.2 In general,the powder should be tested in the as-received condition.In certain instances the powder may bedried.However,if the powder is susceptible to oxidation,thedrying shall take place in a vacuum or in inert gas.If thepowder contains volatile substances,it shall not be dried.6.3 The test shall be carried out on three test portions,ifpossible.7.Procedure7.1 Clean the inside wall of the graduated cylinder(see 5.2)with a suitable clean brush or,if necessary,by rinsing with a1This specification is under the jurisdiction of ASTM Committee B09 on MetalPowders and Metal Powder Products and is the direct responsibility of Subcom-mittee B09.03 on Refractory Metal Powders.Current edition approved April 1,2015.Published April 2015.Originallyapproved in 1970.Last previous edition approved in 2014 as B527 2014.DOI:10.1520/B0527-15.2For 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 solvent,such as acetone.If a solvent is used,thoroughly drythe cylinder before reuse.7.2 Weigh,to the nearest 0.1 g,the mass of the test portionas indicated in Table 1,using a balance(see 5.1).7.3 Pour the test portion into the graduated cylinder.Takecare that a level surface of the powder is formed.Place thecylinder in the tapping apparatus(see 5.3).Tap the cylinderuntil no further decrease in the volume of the powder takesplace(see Note 1).NOTE1In practi