1、Designation: B212 12B212 13Standard Test Method forApparent Density of Free-Flowing Metal Powders Using theHall Flowmeter Funnel1This standard is issued under the fixed designation B212; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi
2、on, 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 Department of Defense.1. Scope*1.1 This test method des
3、cribes a procedure for determining the apparent density of free-flowing metal powders, and mixedpowders; and is suitable for only those powders that will flow unaided through the specified Hall Flowmeter funnel.1.2 With the exception of the values for mass, volume, and density, for which the use of
4、the gram and the cubic centimeter unitsis the long-standing industry practice, the values stated in inch-pound units are to be regarded as standard. The values given inparentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.3 This
5、 standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.
6、1 ASTM Standards:2B215 Practices for Sampling Metal PowdersB243 Terminology of Powder MetallurgyB873 Test Method for Measuring Volume of Apparent Density Cup Used in Test Methods B 212, B 329, and B 417E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method3
7、. Terminology3.1 DefinitionsFor definitions of terms used in this test method, see Terminology B243. Additional descriptive PMinformation is available in the Related Materials section of VolVol. 02.05 of the Annual Book of ASTM Standards.4. Summary of Test Method4.1 A volume of powder is permitted t
8、o flow into a container of definite volume under controlled conditions. The mass ofpowder per unit volume is determined and reported as apparent density, Hall (ADH).5. Significance and Use5.1 This test method provides a guide for evaluation of an important physical characteristic of a powder known a
9、s the apparentdensity. The measured apparent density bears a relationship to the mass of powder that will fill a fixed volume die cavity. Thedegree of correlation between the results of this test and the performance of powders during use may vary with each particularapplication. Note, however, that
10、the presence of moisture, oils, stearic acid, stearates, waxes, and the temperature of the powdermass may alter the physical characteristics of the powder.1 This test method is under the jurisdiction ofASTM Committee B09 on Metal Powders and Metal Powder Products and is the direct responsibility of
11、Subcommittee B09.02on Base Metal Powders.Current edition approved April 1, 2012April 1, 2013. Published September 2012June 2013. Originally approved in 1946. Last previous edition approved in 20092012 asB212 09B212 12. . DOI: 10.1520/B0212-12.10.1520/B0212-13.2 For referencedASTM standards, visit th
12、eASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an
13、 indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to
14、 be considered the official document.*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 States16. Apparatus6.1 Powder Flowmeter Funnel3A Hall Flowmeter funnel (Fig. 1) having a ca
15、librated orifice.6.2 Density CupCupA cylindrical brass cup (Fig. 2) having a nominal capacity of 25 cm3. The actual cup volume shall bedetermined according to Test Method B873. If the measured volume of the cup is outside the tolerance in Fig. 2(25 6 0.03 cm3) the cup shall not be used.6.3 Stand3Ast
16、and (Fig. 1) to support the Hall Flowmeter funnel concentric with the density cup so that the bottom of the HallFlowmeter funnel orifice is approximately 25 mm (1 in.)1 in. (25 mm) above the top of the density cup when the apparatus isassembled as shown in Fig. 1.6.4 WorkbenchA level, vibration-free
17、 table or workbench to support the powder flowmeter standstand.6.5 BalanceA balance, readable to 0.001 g, having a capacity of at least 200 g capable of determining the mass to the nearest0.01 g.6.6 Spatula or straight edgeAnon-magnetic spatula or straight edge of suitable dimensions for leveling of
18、f the excess powderon top of the density cup.7. Test Portion7.1 The test portion shall consist of a volume of approximately 30 to 40 cm3 of metal powder obtained in accordance withPractices B215.3 The sole source of supply of the apparatus known to the committee at this time is ACuPowder Internation
19、al, LLC, 901 Lehigh Ave., Union, NJ 07083-7632. If you areaware of alternative suppliers, please provide this information to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee,1 which you may attend.FIG. 1 Flowmeter Ap
20、paratus Hall FunnelB212 1327.2 The test portion shall be tested as sampled.8. Procedure8.1 Weigh the empty density cup to the nearest 0.01 g or, alternatively, place the empty density cup on the balance and tare thebalance to zero.8.2 Carefully load the test portion into the flowmeter funnel and per
21、mit it to run into the density cup through the dischargeorifice. Take care not to move the density cup.8.3 After the powder has completely filled the cup and has begun to overflow the periphery of the density cup, rotate the funnelapproximately 90 in a horizontal plane so that the remaining powder f
22、alls away from the cup.8.4 Using a nonmagnetic spatula with the blade held perpendicular to the top edge of the cup, level off the powder flush withthe top of the density cup. Take care to avoid jarring the apparatus at any time.8.5 After the leveling operation, tap the density cup lightly on the si
23、de to settle the powder to avoid spilling during transfer.Wipeoff any powder sticking to the outside wall of the cup.8.6 Transfer the filled density cup to the balance and weigh to the nearest 0.01 g to determine the mass, M, of powder.8.7 More than one apparent density test may be run if desired. U
24、se a fresh test portion of powder for each test. Average theapparent density values.9. Calculation9.1 Calculate the apparent density as follows:ADH 5MV (1)FIG. 2 Density Cup (25 6 0.03 cm3)B212 133where:M = mass of powder in the density cup, g.V = volume of the density cup, cm3.ADH = apparent densit
25、y, Hall, g/cm3.10. Report10.1 Report the results as apparent density, Hall (ADH) to the nearest 0.01 g/cm3.11. Precision and Bias11.1 An interlaboratory study of the Hall apparent density was conducted in 1992. The design of the study followed PracticeE691E691 Unfortunately, details of the study wer
26、e not summarized in a Research Report. Nevertheless, the precision of this testmethod as determined by the statistical examination of the interlaboratory test results is as follows:11.1.1 Repeatability r = 1.5 %1.5%Duplicate analyses of unlubricated or lubricated metal powders by the same operator a
27、ndsame apparatus should not differ by more than 1.5 %1.5% at the 95 %95% confidence level.11.1.2 Reproducibility R = 3 %3% (unlubricated and lubricated iron powder), R = 5 %5% (lubricated brass and bronzepowders). The difference between two single and independent results obtained by different operat
28、ors working in differentlaboratories on lubricated and unlubricated iron powders should not differ by more than 3 %3% at the 95 %95% confidence level.Analyses of lubricated brass and bronze metal powders should not differ by more than 5 %5% at the 95 %95% confidence level.11.2 BiasNo information can
29、 be presented on the bias of the procedures inTest Methods B212 for measuring the Hall apparentdensity because no material having an accepted reference value is available.11.3 Measurement UncertaintyThe precision of Test Method B212 shall be considered by those performing the test whenreporting Hall
30、 apparent density test results.12. Keywords12.1 apparent density; Hall flowmeter funnel; metal powdersSUMMARY OF CHANGESSubcommitteeCommittee B09.02 has identified the location of selected changes to this standard since the lastissue (B212 09B212 12) that may impact the use of this standard. (Approv
31、ed April 1, 2013.)(1) Changed the statement on the use of units in Section 1.2.(2) Modified the description of the balance in Section 6.5.(3) Changed “test specimen” to “test portion” in Sections 7.1, 7.2, and 8.2.(4) Added a new section 8.7 to the Procedure to indicate that more than one test may b
32、e run if desired.(5) Noted that an interlaboratory study was conducted in 1992 following Practices E691 but that the results were not summarizedin a Research Report.(6) Added a statement on measurement uncertainty Section 11.3.(1) Placed the inch-pound units first in Fig. 1, removed the tolerances a
33、s the dimensions are nominal and not controlling factorsfor the flowmeter funnel.A statement has been added to Section 6.2 to indicate that if the measured volume of the cup is outsidethe tolerance in Figure 2 the cup shall not be used.ASTM International takes no position respecting the validity of
34、any patent rights asserted in 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 r
35、evision at any time by the responsible 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. You
36、r comments will receive careful 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 copy
37、righted by ASTM International, 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).B212 134
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