1、Designation: B 212 99 (Reapproved 2006)Standard Test Method forApparent Density of Free-Flowing Metal Powders Using theHall Flowmeter Funnel1This standard is issued under the fixed designation B 212; the number immediately following the designation indicates the year oforiginal adoption or, in the c
2、ase of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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. Scope1.1 This te
3、st method describes a procedure for determiningthe apparent density of free-flowing metal powders and issuitable for only those powders that will flow unaided throughthe specified Hall flowmeter funnel.1.2 This standard does not purport to address all of thesafety concerns, if any, associated with i
4、ts 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:2B 215 Practices for Sampling Metal PowdersB 243 Terminology of Powder
5、MetallurgyB 873 Test Method for Measuring Volume of ApparentDensity Cup Used in Test Methods B 212, B 329, and B4173. Terminology3.1 DefinitionsFor definitions of terms used in this testmethod, see Terminology B 243.4. Summary of Test Method4.1 Avolume of powder is permitted to flow into a container
6、of definite volume under controlled conditions. The mass ofpowder per unit volume is determined and reported as apparentdensity, Hall.5. Significance and Use5.1 This test method provides a guide for evaluation of theapparent density physical characteristic of powders. The den-sity measured bears a r
7、elationship to the mass of powder thatwill fill a fixed volume press cavity when parts are being made.The degree of correlation between the results of this test andthe quality of powders in use will vary with each particularapplication.6. Apparatus6.1 Powder Flowmeter Funnel3A Hall flowmeter funnel(
8、Fig. 1) having a calibrated orifice.6.2 Density Cup3A cylindrical brass cup (Fig. 2) having acapacity of 25 cm3. The actual cup volume shall be determinedaccording to Test Method B 873.6.3 Stand3A stand (Fig. 1) to support the Hall flowmeterfunnel concentric with the density cup so that the bottom o
9、f theHall flowmeter funnel orifice is approximately 25 mm (1 in.)above the top of the density cup when the apparatus isassembled as shown in Fig. 1.6.4 BaseA level, vibration-free base to support the pow-der flowmeter.6.5 Balance, having a capacity of at least 200 g and asensitivity of 0.01 g.7. Tes
10、t Specimen7.1 The test specimen shall consist of a volume of approxi-mately 30 to 40 cm3of metal powder obtained in accordancewith Practices B 215.7.2 The test specimen shall be tested as sampled. Note,however, that temperature, moisture, oils, stearic acid, stear-ates, waxes, and so forth, may alte
11、r the characteristics of thepowder.8. Procedure8.1 Weigh the empty density cup to the nearest 0.1 g or,alternatively, place the empty density cup on the balance andtare the balance to zero.1This test method is under the jurisdiction of ASTM Committee B09 on MetalPowders and Metal Powder Products and
12、 is the direct responsibility of Subcom-mittee B09.02 on Base Metal Powders.Current edition approved April 1, 2006. Published April 2006. Originallyapproved in 1946. Last previous edition approved in 1999 as B 212 99.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact AST
13、M Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3The sole source of supply of the apparatus known to the committee at this timeisAccu Powder International, LLC, 901 LehighAve., Union, NJ 07083
14、-7632. If youare aware of alternative suppliers, please provide this information to ASTMInternational Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee,1which you may attend.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C
15、700, West Conshohocken, PA 19428-2959, United States.8.2 Carefully load the test specimen into the flowmeterfunnel and permit it to run into the density cup through thedischarge orifice. Take care not to move the density cup.8.3 When the powder completely fills and overflows theperiphery of the dens
16、ity cup, rotate the funnel approximately90 in a horizontal plane so that the remaining powder fallsaway from the cup.8.4 Using a nonmagnetic spatula with the blade held per-pendicular to the top of the cup, level off the powder flush withthe top of the density cup. Take care to avoid jarring theappa
17、ratus at any time.8.5 After the leveling operation, tap the density cup lightlyon the side to settle the powder to avoid spilling in transfer.FIG. 1 Flowmeter Apparatus Hall FunnelFIG. 2 Density Cup (25 6 0.03 cm2)B 212 99 (2006)28.6 Transfer the filled density cup to the balance and weighto the nea
18、rest 0.1 g to determine the mass, M, of powder.9. Calculation9.1 Calculate the apparent density as follows:Apparent density, g/cm35 M/V (1)where:M = mass of powder in the density cup in grams andV = volume of the density cup, cm3.10. Report10.1 Report the results as apparent density, Hall to thenear
19、est 0.01 g/cm3.11. Precision and Bias11.1 PrecisionThe precision of this test method as deter-mined by the statistical examination of the interlaboratory testresults is as follows:11.1.1 Repeatability r = 1.5 %Duplicate analyses of un-lubricated or lubricated metal powders by the same operatorand sa
20、me apparatus should not differ by more than 1.5 % at the95 % confidence level.11.1.2 Reproducibility R = 3 % (unlubricated and lubri-cated iron powder), R = 5 % (lubricated brass and bronzepowders). The difference between two single and independentresults obtained by different operators working in d
21、ifferentlaboratories on lubricated and unlubricated iron powdersshould not differ by more than 3 % at the 95 % confidencelevel. Analyses of lubricated brass and bronze metal powdersshould not differ by more than 5 % at the 95 % confidencelevel.11.2 BiasSince there is no accepted reference material f
22、ordetermining the bias for the procedure in Test Method B 212for measuring apparent density, Hall, bias has not beendetermined.12. Keywords12.1 apparent density; Hall flowmeter funnel; metalpowdersASTM International takes no position respecting the validity of any patent rights asserted in connectio
23、n 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 responsible
24、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 careful consid
25、eration 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 International, 100 Bar
26、r 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).B 212 99 (2006)3
