1、Designation:B21209 Designation: B212 12Standard 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 ca
2、se 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.This standard has been approved for use by agencies of the Department of Defense.1. Scope*1.1 This tes
3、t method 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.1.2With the exception of density values, for which the g/cm3unit is the indus
4、try standard, the values stated in SI units are tobe regarded as the standard. Values in inch-pound units are shown in parentheses and result from conversion in accordance withIEEE/ASTM Standard SI 10. They may be approximate and are only for information.1.2 With the exception of the values for mass
5、, volume, and density, for which the use of 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 o
6、nly and are not considered standard.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 regulatorylimita
7、tions prior to use.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 B 212, B 329, and B 4172.2 IEEE/ASTM Standard:2SI 10American National Standar
8、d for Use of the International System of Units (SI): The Modern Metric System3. 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 AST
9、M Standards.4. Summary of Test Method4.1 A volume 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
10、for evaluation of an important physical characteristic 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
11、 during use may vary with each particularapplication. 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.1This test method is under the jurisdiction of ASTM Committee B09 on Me
12、tal Powders and Metal Powder Products and is the direct responsibility of SubcommitteeB09.02 on Base Metal Powders.Current edition approved Nov.April 1, 2009.2012. Published January 2010.September 2012. Originally approved in 1946. Last previous edition approved in 20062009 asB21299(2006)B212 09 . D
13、OI: 10.1520/B0212-09.10.1520/B0212-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.1This document is not
14、 an ASTM standard and is intended only to provide the user 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
15、. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.
16、 Apparatus6.1 Powder Flowmeter Funnel3A Hall Flowmeter funnel (Fig. 1) having a calibrated orifice.6.2 Density Cup3A cylindrical brass cup (Fig. 2) having a nominal capacity of 25 cm3. The actual cup volume shall bedetermined according to Test Method B873.6.3 Stand3Astand (Fig. 1) to support the Hal
17、l Flowmeter funnel concentric with the density cup so that the bottom of the HallFlowmeter funnel orifice is approximately 25 mm (1 in.) above the top of the density cup when the apparatus is assembled asshown in Fig. 1.6.4 BaseA level, vibration-free base to support the powder flowmeter. WorkbenchA
18、 level, vibration-free table orworkbench to support the powder flowmeter stand6.5 Balance A laboratory balance, having a capacity of at least 200 g and a sensitivity of 0.001 g. A balance, readable to0.001 g, having a capacity of at least 200 g capable of determining the mass to the nearest 0.01 g.6
19、.6 Spatula or straight edgeAnon-magnetic spatula or straight edge of suitable dimensions for leveling off the excess powderon top of the density cup.7. Test SpecimenPortion7.1 The test specimenportion shall consist of a volume of approximately 30 to 40 cm3of metal powder obtained in accordancewith P
20、ractices B215.7.2 The test specimenportion shall be tested as sampled.3The sole source of supply of the apparatus known to the committee at this time is Accu PowderACuPowder International, LLC, 901 Lehigh Ave., Union, NJ 07083-7632.If you are aware of alternative suppliers, please provide this infor
21、mation to ASTM International Headquarters. Your comments will receive careful consideration at a meetingof the responsible technical committee, which you may attend.FIG. 1 Flowmeter Apparatus Hall FunnelB212 1228. Procedure8.1 Weigh the empty density cup to the nearest 0.01 g or, alternatively, plac
22、e the empty density cup on the balance and tare thebalance to zero.8.2 Carefully load the test specimenportion into the flowmeter funnel and permit it to run into the density cup through thedischarge orifice. Take care not to move the density cup.8.3 After the powder has completely filled the cup an
23、d has begun to overflow the periphery of the density cup, rotate the funnelapproximately 90 in a horizontal plane so that the remaining 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
24、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 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
25、 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. Use a fresh test portion of powder for each test. Average theapparent density values.9. Calculation9.1 Calculate the apparent density as follows:ADH5MV(1)B0
26、212-12_1where:M = mass of powder in the density cup, g.V = volume of the density cup, cm3.ADH= apparent density, Hall.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 Bias11.1PrecisionThe precision of this tes
27、t method as determined by the statistical examination of the interlaboratory test resultsis as follows:11.1 An interlaboratory study of the Hall apparent density was conducted in 1992. The design of the study followed PracticeE691. Unfortunately, details of the study were not summarized in a Researc
28、h 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 r = 1.5 % Duplicate analyses of unlubricated or lubricated metal powders by the same operator and sameapparatus should not diff
29、er by more than 1.5 % at the 95 % confidence level.11.1.2 Reproducibility R = 3 % (unlubricated and lubricated iron powder), R = 5 % (lubricated brass and bronze powders). Thedifference between two single and independent results obtained by different operators working in different laboratories onlub
30、ricated 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.FIG. 2 Density Cup (25 6 0.03 cm3)B212 12311.2 BiasSince there is no accepted re
31、ference material for determining the bias for the procedure in Test Method B212 formeasuring apparent density, Hall, bias has not been determined. No information can be presented on the bias of the proceduresin Test Methods B212 for measuring the Hall apparent density because no material having an a
32、ccepted reference value is available.11.3 Measurement UncertaintyThe precision of Test Method B212 shall be considered by those performing the test whenreporting Hall apparent density test results.12. Keywords12.1 apparent density; Hall flowmeter funnel; metal powders12.1 apparent density; Hall flow
33、meter funnel; metal powdersSUMMARY OF CHANGESSubcommittee B09.02 has identified the location of selected changes to this standard since the last issue(B212 09) that may impact the use of this standard.(1) Changed the statement on the use of units in Section 1.2.(2) Modified the description of the ba
34、lance 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 be run if desired.(5) Noted that an interlaboratory study was conducted in 1992 following Practices E691 but that the
35、results were not summarizedin a Research Report.(6) Added a statement on measurement uncertainty Section 11.3.(7) Placed the inch-pound units first in Fig. 1, removed the tolerances as the dimensions are nominal and not controlling factorsfor the flowmeter funnel.ASTM International takes no position
36、 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 infringement of such rights, are entirely their own responsibility.T
37、his standard is subject to revision 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 In
38、ternational Headquarters. Your 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 show
39、n below.This standard is copyrighted 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 124
