1、Designation: B 527 06Standard Test Method forDetermination of Tap Density of Metallic Powders andCompounds1This standard is issued under the fixed designation B 527; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 metallic powders andcompoun
3、ds, that is, the density of a powder that has beentapped, to settle contents, in a container under specifiedconditions.1.2 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-pri
4、ate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2B 215 Practices for Sampling Metal Powders3. Significance and Use3.1 This test method covers the evaluation of the tappeddensity physical characteristic
5、of metallic powders and 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.4. Apparatus4.1 Balance, of appropriate capacity and accuracy to satisfythe requirements
6、shown in Table 1.4.2 Graduated Glass Cylinder, calibrated to contain 100cm3at 20C, 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 cm3cyli
7、nder.4.2.1 Alternatively, the following may be used:4.2.1.1 Graduated Glass Cylinder, calibrated to contain 25cm3at 20C, the height of the graduated portion beingapproximately 135 mm. The graduations shall be at 0.2 cm3intervals.4.2.1.2 A 25-cm3cylinder shall be used for powders ofapparent density h
8、igher than 4 g/cm3, in particular for refrac-tory metal powders, but may also be used for powder of lowerapparent density.4.3 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 withouta
9、ny loosening of its surface layers. The stroke shall be 3 mm(0.118 in.) and the tapping frequency shall be between 100 and300 taps/min. An example of a tapping apparatus is shown inFig. 1.5. Test Specimen5.1 For the quantities of powder required for each test, seeTable 1. Obtain test powder samples
10、according to PracticesB 215.5.2 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
11、 shall not be dried.5.3 The test shall be carried out on three test samples, ifpossible.6. Procedure6.1 Clean the inside wall of the graduated cylinder (see 4.2)with a suitable clean brush or, if necessary, by rinsing with asolvent, such as acetone. If a solvent is used, thoroughly drythe cylinder b
12、efore reuse.1This 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 Oct. 1, 2006. Published October 2006. Originallyapproved in 1970. La
13、st previous edition approved in 2000 as B 527 93 (2000)e1.2For 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.TAB
14、LE 1 Accuracy and Capacity of BalanceCylinder Capacity, cm3Apparent Density, g/cm3Mass of Test Portion, g100 1 100 6 0.5100 #1506 0.225 7 100 6 0.525 2to7 506 0.225 2 20 6 0.11*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Bo
15、x C700, West Conshohocken, PA 19428-2959, United States.6.2 Weigh, to the nearest 0.1 g, the mass of the test portionas indicated in Table 1, using a balance (see 4.1).6.3 Pour the test portion into the graduated cylinder. Takecare that a level surface of the powder is formed. Place thecylinder in t
16、he tapping apparatus (see 4.3). Tap the cylinderuntil no further decrease in the volume of the powder takesplace (see Note 1).NOTE 1In practice, the minimum number of taps, N, such that nofurther change in volume takes place would be determined. For all furthertests on the same type of powder, the c
17、ylinder would be subjected to 2Ntaps, except where general experience and acceptance have established aspecific number of taps (no less than N taps) as being satisfactory. For finerefractory metal powders, 3000 taps has been found to be satisfactory forall sizes.6.4 If the tapped surface is level, r
18、ead the volume directly. Ifthe tapped surface is not level, determine the tap volume bycalculating the mean value between the highest and the lowestreading of the tapped surface. Read the final volume to thenearest 0.5 cm3when using a 100 cm3cylinder and to thenearest 0.2 cm3when using a 25 cm3cylin
19、der.7. Calculation7.1 The tap density is given in the following equationPt 5MV(1)where:Pt = tap density, g/cm3,M = mass of powder, g, andV = volume of tapped powder, cm3.8. Report8.1 Report the following information:8.1.1 Reference to this test method,8.1.2 All details necessary for identification o
20、f the testsample,8.1.3 The drying procedure, if the powder has been dried,8.1.4 Cylinder capacity, mass of test portion and methodused,8.1.5 All results obtained,8.1.6 All operations not specified in this test method orregarded as optional,8.1.7 Details of any occurrence that may have affected there
21、sult.9. Precision and Bias9.1 PrecisionIt is not possible at present to specify theprecision and bias of the procedure in Test Method B 527 formeasuring the tap density of metal powders and compounds.An interlaboratory study is currently in process.10. Keywords10.1 apparent density; bulk density; de
22、nsity; density ratio;metal powders; packed density; powder metallurgy; tap densityFIG. 1 Example of Tapping ApparatusB527062SUMMARY OF CHANGESCommittee B09 has identified the location of selected changes to this standard since the last issue (B 527 93(2000)e1) that may impact the use of this standar
23、d. (Approved Oct. 1, 2006.)(1) Edit changes were made throughout.(2) Removed references to equipment suppliers because theequipment is available from more than one source.(3)In5.3, added “if possible” since often there is not asufficient quantity of powder available for three independenttests withou
24、t reusing the materials.(4)In8.1.5, changed “the” to “all”.(5) In Section 9, replaced precision and bias statement withstandard statement from the ASTM Form and Style Manual.(6)InTable 1, changed “1” to “#1”.ASTM International takes no position respecting the validity of any patent rights asserted i
25、n connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the r
26、esponsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive car
27、eful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM Internation
28、al, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).B527063
