1、Designation: B527 14B527 15Standard Test Method forDetermination of Tap Density of Metal Powders andCompounds1This standard is issued under the fixed designation B527; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of las
2、t revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method specifies a method for the determination of tap density (packed density) of metal powders and compounds
3、,that is, the density of a powder that has been tapped, to settle contents, in a container under specified conditions.1.2 With the exception of the values for density and the mass used to determine density, for which the use of the gram per cubiccentimetre (g/cm3) and gram (g) units is the long-stan
4、ding industry practice, the values in SI units are to be regarded as 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 deter
5、mine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2B215 Practices for Sampling Metal PowdersB243 Terminology of Powder MetallurgyE177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE456 Terminology Relating to Quality and Sta
6、tisticsE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method3. Terminology3.1 Definitions of Terms Specific to This Standard:Terms used in this test method are defined in B243.4. Significance and Use4.1 This test method covers the evaluation of the tap den
7、sity physical characteristic of metal powders and related compounds.The degree of correlation between the results of this test method and the quality of powders in use will vary with each particularapplication and has not been fully determined.5. Apparatus5.1 Balance, of appropriate capacity to sati
8、sfy the requirements shown in Table 1 and accuracy of 6 0.05 g.5.2 Graduated Glass Cylinder, calibrated to contain 100 cm3 at 20 C, the height of the graduated portion being approximately175 mm. The graduations shall be at 1 cm3 intervals, thus allowing a measuring accuracy of60.5 cm3. For apparent
9、densities over4 g/cm3, do not use the 100 cm3 cylinder, see section 5.2.1.1.5.2.1 Alternatively, the following may be used:5.2.1.1 Graduated Glass Cylinder, calibrated to contain 25 cm3 at 20 C, the height of the graduated portion beingapproximately 135 mm. The graduations shall be at 0.2 cm3 interv
10、als, thus allowing a measuring accuracy of 60.1 cm3.5.2.1.2 A 25 cm3 cylinder shall be used for powders of apparent density higher than 4 g/cm3, in particular for refractory metalpowders.1 This specification is under the jurisdiction of ASTM Committee B09 on Metal Powders and Metal Powder Products a
11、nd is the direct responsibility of SubcommitteeB09.03 on Refractory Metal Powders.Current edition approved April 1, 2014April 1, 2015. Published August 2014April 2015. Originally approved in 1970. Last previous edition approved in 20062014 asB527 2006.B527 2014. DOI: 10.1520/B0527-14.10.1520/B0527-1
12、5.2 For referencedASTM 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
13、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. In all cases only the current version
14、of the standard as 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 States15.3 Tapping Apparatus, which permits the t
15、apping of the graduated cylinder against a firm base. The tapping shall be such thata densification of the powder can take place without any loosening of its surface layers. The stroke shall be 3 mm and the tappingfrequency shall be between 100 and 300 taps/min. An example of a tapping apparatus is
16、shown in Fig. 1.6. Test Specimen6.1 For the quantities of powder required for each test, see Table 1. Obtain test portions according to Practices B215.6.2 In general, the powder should be tested in the as-received condition. In certain instances the powder may be dried. However,if the powder is susc
17、eptible to oxidation, the drying shall take place in a vacuum or in inert gas. If the powder contains volatilesubstances, it shall not be dried.6.3 The test shall be carried out on three test portions, if possible.TABLE 1 Capacity and Accuracy of the Test Portion Mass andGraduated CylinderApparentDe
18、nsityg/cm3Mass of TestPortiongCylinderCapacitycm3CylinderAccuracycm34 100 0.5 25 0.2FIG. 1 Example of Tapping ApparatusB527 1527. Procedure7.1 Clean the inside wall of the graduated cylinder (see 5.2) with a suitable clean brush or, if necessary, by rinsing with a solvent,such as acetone. If a solve
19、nt is used, thoroughly dry the cylinder before reuse.7.2 Weigh, to the nearest 0.1 g, the mass of the test portion as indicated in Table 1, using a balance (see 5.1).7.3 Pour the test portion into the graduated cylinder. Take care that a level surface of the powder is formed. Place the cylinderin th
20、e tapping apparatus (see 5.3). Tap the cylinder until no further decrease in the volume of the powder takes place (see Note1).NOTE 1In practice, the minimum number of taps, N, such that no further change in volume takes place would be determined. For all further testson the same type of powder, the
21、cylinder would be subjected to 2N taps, except where general experience and acceptance have established a specificnumber of taps (no less than N taps) as being satisfactory. For fine refractory metal powders, 3000 taps has been found to be satisfactory for all sizes.7.4 If the tapped surface is leve
22、l, read the volume directly. If the tapped surface is not level, determine the tap volume bycalculating the mean value between the highest and the lowest reading of the tapped surface. Read the final volume to the nearest0.5 cm3 when using a 100 cm3 cylinder and to the nearest 0.2 cm3when using a 25
23、 cm3 cylinder.8. Calculation8.1 The tap density is given in the following equationTD 5MV (1)where:TD = tap density, g/cm3,M = mass of powder, g, andV = volume of tapped powder, cm3.9. Report9.1 Report the following information:9.1.1 Reference to this test method,9.1.2 All details necessary for ident
24、ification of the test sample,9.1.3 The drying procedure, if the powder has been dried,9.1.4 Cylinder capacity, mass of test portion and method used,9.1.5 All results obtained. Report tap density to the nearest 0.1 g/cm3 for powders with apparent densities up to and including4 g/cm3. For powders with
25、 apparent densities higher than 4 g/cm3, report to the nearest 0.2 g/cm3;9.1.6 All operations not specified in this test method or regarded as optional, and9.1.7 Details of any occurrence that may have affected the result.10. Precision and Bias10.1 PrecisionThe precision of this test method is based
26、 on an intralaboratory study of Test Method B527, conducted in20112012.Asingle laboratory with two operators analyzed three different powders for tap density. Either 10 or 20 replicates werereported for each material in this study. Except for testing in just one lab, Practice E691 was followed for t
27、he study design; thedetails are given in ASTM Research Report No. RR:B09-1020.3 The precision statement was determined through statisticalexamination of 50 results, from a single laboratory, testing three materials. The materials were designated in the study as:1. Cermet (TiC based), apparent densit
28、y 1.02 g/cm32. Iron (Ancorsteel 1000), apparent density 2.92 g/cm33. Tungsten carbide (WC), apparent density 6.91 g/cm310.1.1 Test ResultsThe precision information presented herein has been calculated for the comparison of three materials, eachof which is the mathematical average of ten or twenty in
29、dividual test determinations.10.1.1.1 95 % Repeatability Limit (r)Two test results obtained within one laboratory shall be judged not equivalent if theydiffer by more than the r value for that material; r is the interval representing the critical difference between two test results forthe same mater
30、ial, using the same mass and appropriate volumetric cylinder capacity according to Table 1. Repeatability limits arelisted in Table 2. The within-laboratory repeatability limit, r, as defined by Terminology E456, is dependent on the apparent densityof the tested material (see Table 2). At the 95 % c
31、onfidence level, duplicate tap density results from the same laboratory shouldnot be considered to be different unless they differ by more than r.10.1.1.2 Reproducibility Limit (R)The reproducibility limit of this test method is being determined and will be available inDecember, 2019. Reproducibilit
32、y results cannot be determined from a single laboratory study.3 Supporting data have been filed at ASTM International Headquarters and may be obtained by requesting Research Report RR:B09-1020. Contact ASTM CustomerService at serviceastm.org.B527 15310.2 BiasNo information can be presented on the bi
33、as of the procedure in Test Method B527 for measuring tap densitybecause no material having an accepted reference value is available.10.3 The above terms (“repeatability limit” and “reliability limit”) are used as specified in Practice E177.10.4 Any judgment in accordance with statement 10.1.1 would
34、 normally have an approximate 95 % probability of being correct,however because of the limited number of participants in this study, consider the precision noted as an estimate.11. Keywords11.1 apparent density; bulk density; density; density ratio; metal powders; packed density; powder metallurgy;
35、tap densitySUMMARY OF CHANGESCommittee B09 has identified the location of selected changes to this standard since the last issue (B527 14)that may impact the use of this standard. (Approved April 1, 2015.)(1) Removed “Determination of” from the title.SUMMARY OF CHANGESCommittee B09 has identified th
36、e location of selected changes to this standard since the last issue (B527 06)that may impact the use of this standard. (Approved April 1, 2014.)(1) Changed “metallic” to “metal” in the title.(2) Section 3 on Terminology was added and subsequent sections were renumbered.(3) Units statement added to
37、the Scope, Section 1, indicating that the standard uses SI, and removed inch-pound units.(4) Minor editorial changes were made throughout.(5) Clarifications in some sections regarding accuracy.(6) In 5.2.1.2, delete phrase allowing the use of 25 cm3 cylinder for lower density powders.Alarger volume
38、cylinder must be usedfor powders with density less than 4 g/cm3.(7) Replacement of Table 1. Mass of sample used and capacity of the graduated cylinder was modified to be consistent with otherinternational standards following the analysis of published data.(8) Addition of data in Section 10.(9) Chang
39、es made to acronyms to conform with newly accepted B09 Policy Guide, e.g., Pt for tap density is now TD.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
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43、ts (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 Copy
44、right Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 2 Tap Density (g/cm3)Material(100 gm per run)CylinderCapacitycm3AverageAxRepeatabilityStandardDeviationsrRepeatabilityLimitrCermet 20replicates 100 1.6 0.02 0.06Iron 20 replicates 100 3.7 0.10 0.29Tungsten Carbide(WC) 10 replicates25 8.2 0.07 0.20AThe average of the laboratories calculated averages.B527 154
