ASTM B703-21

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it 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
of the standard as published by ASTM is to be considered the official document.
Designation: B703 − 17 B703 − 21
Standard Test Method for
Apparent Density of Metal Powders and Related
Compounds Using the Arnold Meter
This standard is issued under the fixed designation B703; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 This test method covers a quantitative laboratory procedure for determining the apparent density of both free-flowing and
non-free-flowing metal powders, lubricated metal powder mixtures, and powder compounds.
1.2 Units—With the exception of the values for mass, volume, and density, for which the use of the gram and the cubic centimetre
units is the long-standing industry practice, the values stated in inch-pound units are to be regarded as standard. The values given
in parentheses are mathematical conversions to SI units that are provided for information only 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 responsibility
of the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
B212 Test Method for Apparent Density of Free-Flowing Metal Powders Using the Hall Flowmeter Funnel
B215 Practices for Sampling Metal Powders
B243 Terminology of Powder Metallurgy
B329 Test Method for Apparent Density of Metal Powders and Compounds Using the Scott Volumeter
B417 Test Method for Apparent Density of Non-Free-Flowing Metal Powders Using the Carney Funnel
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E456 Terminology Relating to Quality and Statistics
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
2.2 MPIF Standard:
MPIF 48 Determination of Apparent Density of Metal Powders Using the Arnold Meter
This test method is under the jurisdiction of ASTM Committee B09 on Metal Powders and Metal Powder Products and is the direct responsibility of Subcommittee B09.02
on Base Metal Powders.
Current edition approved Sept. 1, 2017Sept. 1, 2021. Published September 2017September 2021. Originally approved in 1983. Last previous edition approved in 20102017
as B703B703 – 17. –10. DOI: 10.1520/B0703-17.10.1520/B0703-21.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
This reportstandard is available from Metal Powder Industries Federation, Federation (MPIF), 105 College RoadRd. East, Princeton, NJ 0854008540, http://
www.mpif.org.
*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
B703 − 21
3. Terminology
3.1 Definitions—Useful definitions of terms for metal powders and powder metallurgy (PM) are found in Terminology B243.
Additional descriptive PM information is available at www.astm.org on the B09 web page, under the Committee Documents
section, following the link for “General Information on PM.”
3.2 Definitions of Terms Specific to This Standard:
3.2.1 Arnold Apparent Density (AD )—), n—the mass per unit volume of a powder, expressed in gram per cubic centimetre units,
A
determined in accordance with the procedure in this test method.
3.2.2 Arnold Meter—Meter, n—the laboratory instrumentation pictured in Fig. 1, consisting of a steel die block with a precise
cavity and a powder delivery cylinder, that is used to determine a quantitative value for Arnold Apparent Density, (AD ).
A
4. Summary of Test Method
4.1 The test method consists of first collecting a 20 cm volume of the test powder by slowly sliding a cylindrical sleeve containing
the test powder over a precise cavity in a die block.
4.2 The mass of the volume of powder thus collected is determined and the Arnold Apparent Density (AD ), is calculated as mass
A
divided by volume and expressed in g/cm units.
5. Significance and Use
5.1 The apparent density is an important measure of a material characteristic of the powder that is useful to the powder producers
and powder users in determining quality and lot to lot consistency.
5.2 This test method is applicable to free-flowing and non-free-flowing metal powders, lubricated powder mixtures and metal
compounds.
5.3 The apparent density of a lubricated metal powder mixture may be different when a quantity settles after falling into the die
cavity during automaticautomated compacting as compared with the value obtained from a measurement taken in the laboratory
under controlled test conditions.
5.4 This test method simulates the action of the feed shoe on a powder compacting press and gives an apparent density value that
closely approximates the apparent density of the powder in the die cavity after the production filling operation.
FIG. 1 Arnold Meter
B703 − 21
5.5 Knowledge of this apparent density value for the final lubricated production powder mixture is very helpful to the powder
metallurgy (PM) parts fabricator to set the compression ratios for fixed fill die cavity tooling.
5.6 The values of apparent density obtained on metal powders with this test method are approximately 0.2 g/cm higher than those
obtained using the Hall Funnel, Test Method B212, the Carney Funnel, Test Method B417; or the Scott Volumeter, Test Method
B329.
5.7 This test method may be part of a purchase agreement between the powder supplierproducer and PM parts producer, or it may
be an internal quality control test for either party.
6. Apparatus
6.1 Steel Die Block —A hardened, tempered (60 HRC min.), ground and demagnetized tool steel block approximately 6.50 by
2.50 in. (165 by 64 mm) and 1.0000 6 0.0001 in. (25.400 6 0.003 mm) in thickness, having a precise centrally located
through-hole 1.2466 6 0.0001 in. (31.664 6 0.003 mm) in diameter with a volume of 20.0 cm (see Fig. 2). The surfaces of the
sides of the die block shall be given a roughening treatment to aid in handling during use (see Fig. 1).
6.2 Powder Delivery Cylinder —A nonferrous cylindrical sleeve, preferably brass or bronze, approximately 1.75 in. (44 mm)
outside diameter and 1.50 in. (38 mm) inside diameter with a height of about 1.50 in. (38 mm), (see Fig. 2). The cylinder should
be inscribed on the ID with a ring at approximately three quarters of its height to indicate 50 cm .
6.3 Weighing Paper—A sheet of coated or waxed paper approximately 6.06 in. (150 mm) square.
6.4 Balance—A laboratory balance readable to 0.001 g, and with a capacity of at least 200 g, to be used for determining the mass
of the test specimen to the nearest 0.01 g.
7. Test Portion
7.1 The test portion shall be approximately 50 cm of powder, obtained in accordance with Practices B215, that will fill the
delivery cylinder to about three quarters of its height.
8. Procedure
8.1 Tare the sheet of coated weighing paper and lay it on a flat level surface.
8.2 Thoroughly clean the steel die block and the powder delivery cylinder with a dry cotton cloth to remove any loose powder
particles. Demagnetize the die if necessary.
8.3 Place the steel die block in the center of the sheet of tared paper.
8.4 Locate the empty delivery cylinder upright on the steel die block, on either side of the die cavity.
8.5 Carefully fill the delivery cylinder with the 50 cm test portion of powder to the ring inscribed at three-quarters of its height.
8.6 With downward pressure on the delivery cylinder, slowly and smoothly slide it forward across the cavity while simultaneously
rotating i
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