1、Designation: B212 13B212 17Standard 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 U.S. Department of Defense.1. Scope*1.1 This test metho
3、d describes 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 us
4、e of the gram and the cubiccentimetercentimetre units is the long-standing industry practice, the values stated in inch-pound units are to be regarded asstandard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and arenot considered sta
5、ndard.1.3 This 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.1.4 This in
6、ternational standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) C
7、ommittee.2. Referenced Documents2.1 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 B212, B329, and B417E691 Practice for Conducting an Interlaboratory Study to Determine
8、the Precision of a Test Method3. 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 Vol. 02.05 of the Annual Book of ASTM Standards.4. Summary of Test Method4.1 A vol
9、ume of powder is permitted to 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 charac
10、teristic of a powder known as 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 particularappli
11、cation. Note, however, that 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 t
12、he direct responsibility of Subcommittee B09.02on Base Metal Powders.Current edition approved April 1, 2013April 1, 2017. Published June 2013April 2017. Originally approved in 1946. Last previous edition approved in 20122013 asB212 12.B212 13. DOI: 10.1520/B0212-13.10.1520/B0212-17.2 For referencedA
13、STM standards, visit theASTM 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
14、 of an ASTM standard an 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
15、published by ASTM is to 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 calibrated Hall Flo
16、wmeter funnel (Fig. 1) having a calibrated orifice.).6.2 Density CupA 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 cu
17、p shall not be used.6.3 Stand3Astand (Fig. 1) to support the Hall Flowmeter funnel concentric with the density cup so that the bottom of the HallFlowmeter funnel orifice is approximately 1 in. (25 mm) above the top of the density cup when the apparatus is assembled asshown in Fig. 1.6.4 WorkbenchA l
18、evel, vibration-free table or workbench to support the powder flowmeter stand.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
19、for leveling off 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 ACuPow
20、der International, 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.
21、 1 Flowmeter Apparatus Hall FunnelB212 1727.2 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
22、 funnel and permit 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 rem
23、aining powder falls 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 li
24、ghtly on the side 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 ru
25、n if desired. Use 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 173where:M = mass of powder in the density cup, g.V = volume of the density cup, cm3.ADH =
26、apparent density, 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 PracticeE691. Unfortunately, details of t
27、he study were not summarized in a Research Report. Nevertheless, the precision of this test methodas determined by the statistical examination of the interlaboratory test results is as follows:11.1.1 Repeatability limit, r = 1.5%Duplicate analyses of unlubricated or lubricated metal powders by the s
28、ame operator andsame apparatus should not differ by more than 1.5% at the 95% confidence level.11.1.2 Reproducibility limit, R = 3% (unlubricated and lubricated iron powder), R = 5% (lubricated brass and bronze powders).The difference between two single and independent results obtained by different
29、operators working in different laboratories onlubricated and unlubricated iron powders should not differ by more than 3% at the 95% confidence level. Analyses of lubricatedbrass and bronze metal powders should not differ by more than 5% at the 95% confidence level.11.2 BiasNo information can be pres
30、ented 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 apparen
31、t density test results.12. Keywords12.1 apparent density; Hall flowmeter funnel; metal powdersSUMMARY OF CHANGESCommittee B09.02 has identified the location of selected changes to this standard since the last issue(B212 12B212 13) that may impact the use of this standard. (Approved April 1, 2013.)20
32、17.)(1) Section 6.1 has been changed to reflect the use of a calibrated flowmeter funnel rather than orifice.(2) A statement has been added to Section 6.2The text “to the nearest 0.01 g” has been deleted in sections 8.1 toand 8.2indicatethat if the measured volume of the cup is outside the tolerance
33、 in Figure. The mass shall be determined using a balance that isreadable to 0.001 g, as indicated in Section 6.52 the cup , and the values determined shall not be used.rounded until the AD hasbeen calculated.(3) The word “limit” has been added after repeatability and reproducibility in sections 11.1
34、.1 and 11.1.2 respectively.ASTM International takes no position respecting the validity of 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 infri
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