ASTM B331-16

Standard Test Method for Compressibility of Metal Powders in Uniaxial Compaction

SIGNIFICANCE AND USE
5.1 The compressibility value obtained by this test is a measure of a material characteristic of the powder.  
5.2 The test method is useful in research and development projects, as a quality control test in the evaluation and manufacturing control of metal powder production, and as an acceptance test for shipment of metal powder lots.  
5.3 In PM production operations, the test is helpful in determining pressing and tooling requirements for high density parts.  
5.4 Results may be affected by test conditions such as the type, amount, and method of lubrication, dwell time during compaction, and die material. The compressibility values may not necessarily agree with results obtained under production conditions.
SCOPE
1.1 This laboratory test method covers the determination of the compressibility of metal powders and metal powder mixtures as measured by the extent to which a test portion can be densified under controlled conditions in a specified die.  
1.2 With the exception of the values for density and mass, for which the use of gram per cubic centermetre (g/cm3) and gram (g) units is the longstanding 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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Mar-2016
• ICS: 77.160 - Powder metallurgy
• Technical Committee: B09 - Metal Powders and Metal Powder Products
• Drafting Committee: B09.02 - Base Metal Powders

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: B331 − 16
Standard Test Method for
1
Compressibility of Metal Powders in Uniaxial Compaction
This standard is issued under the fixed designation B331; 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* 4. Summary of Test Method
1.1 This laboratory test method covers the determination of
4.1 Atest portion of metal powder is uniaxially compressed
the compressibility of metal powders and metal powder mix-
in a specific die under controlled conditions.
tures as measured by the extent to which a test portion can be
4.2 The green density of the resulting compact is deter-
densified under controlled conditions in a specified die.
mined.
1.2 With the exception of the values for density and mass,
3
4.3 The compressibility of the powder is defined as the
for which the use of gram per cubic centermetre (g/cm ) and
green density of the test compact at the compacting pressure
gram (g) units is the longstanding industry practice, the values
that was used.
stated in inch-pound units are to be regarded as standard. The
values given in parentheses are mathematical conversions to SI
5. Significance and Use
units that are provided for information only and are not
considered standard.
5.1 The compressibility value obtained by this test is a
1.3 This standard does not purport to address all of the
measure of a material characteristic of the powder.
safety concerns, if any, associated with its use. It is the
5.2 The test method is useful in research and development
responsibility of the user of this standard to establish appro-
projects, as a quality control test in the evaluation and
priate safety and health practices and determine the applica-
manufacturing control of metal powder production, and as an
bility of regulatory limitations prior to use.
acceptance test for shipment of metal powder lots.
2. Referenced Documents
5.3 In PM production operations, the test is helpful in
2
2.1 ASTM Standards:
determining pressing and tooling requirements for high density
B215 Practices for Sampling Metal Powders
parts.
B243 Terminology of Powder Metallurgy
5.4 Results may be affected by test conditions such as the
B925 Practices for Production and Preparation of Powder
type, amount, and method of lubrication, dwell time during
Metallurgy (PM) Test Specimens
compaction, and die material. The compressibility values may
B962 Test Methods for Density of Compacted or Sintered
not necessarily agree with results obtained under production
Powder Metallurgy (PM) Products Using Archimedes’
conditions.
Principle
E456 Terminology Relating to Quality and Statistics
6. Apparatus
3. Terminology
6.1 Compacting Tooling—A cemented carbide die or
3.1 Definitions—For definitions of terms used in this test
alternatively, hardened tool steel die and two hardened steel
method refer to Terminology B243.Additional descriptive PM
punches capable of producing the compressibility test speci-
information is available in the Related Material section of Vol
men. The designs shown in Practice B925 for a cylindrical test
02.05 of the Annual Book of ASTM Standards.
specimen and a transverse rupture test specimen are examples
of acceptable tooling.
1
This test method is under the jurisdiction of ASTM Committee B09 on Metal
6.2 Powder Compacting Press—A compression testing ma-
Powders and Metal Powder Productsand is the direct responsibility of Subcommit-
tee B09.02 on Base Metal Powders. chine or powder compacting press, capable of applying an
Current edition approved April 1, 2016. Published April 2016. Originally
adequate load with an accuracy of at least 61.0 % at a rate of
approved in 1958. Last previous edition approved in 2010 as B331– 10.
approximately 30 tsi/min (400 MPa/min).
DOI:10.1520/B0331-16.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
6.3 Balance—Alaboratory balance readable to 0.001 g with
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
a minimum capacity of 100 g to be used to determine the mass
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. of the compacted test specimen to the nearest 0.01 g.
*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
1

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B331 − 16
6.4 Micrometer—Standard outside micrometers or other thick (25.4 in diameter by 7.11 6 0.25 mm thick), as shown in
suitable measuring instruments for determining the dimensions Practice B925
...

This document is not 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. Because
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: B331 − 10 B331 − 16
Standard Test Method for
1
Compressibility of Metal Powders in Uniaxial Compaction
This standard is issued under the fixed designation B331; 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 laboratory test method covers the determination of the compressibility of metal powders and metal powder mixtures
as measured by the extent to which a sample test portion can be densified under controlled conditions in a specified die.
1.2 With the exception of density values, the values for density and mass, for which the g/cmuse of gram per cubic centermetre
3
(g/cm unit ) and gram (g) units is the longstanding industry standard,practice, the values stated in inch-pound units are to be
regarded as the standard. The values showngiven in parenthesisparentheses are mathematical conversions to SI units that are
presentedprovided for information only and are not to be considered 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 responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2
2.1 ASTM Standards:
B215 Practices for Sampling Metal Powders
B243 Terminology of Powder Metallurgy
B925 Practices for Production and Preparation of Powder Metallurgy (PM) Test Specimens
B962 Test Methods for Density of Compacted or Sintered Powder Metallurgy (PM) Products Using Archimedes’ Principle
E456 Terminology Relating to Quality and Statistics
3. Terminology
3.1 Definitions—For definitions of terms used in this test method refer to Terminology B243. Additional descriptive PM
information is available in the Related Material section of Vol 02.05 of the Annual Book of ASTM Standards.
4. Summary of Test Method
4.1 A test sampleportion of metal powder is uniaxially compressed in a specific die under controlled conditions.
4.2 The green density of the resulting compact is determined.
4.3 The compressibility of the powder is defined as the green density of the test compact at the compacting pressure that was
used.
5. Significance and Use
5.1 The compressibility value obtained by this test is a measure of a material characteristic of the powder.
5.2 The test method is useful in research and development projects, as a quality control test in the evaluation and manufacturing
control of metal powder production, and as an acceptance test for shipment of metal powder lots.
5.3 In PM production operations, the test is helpful in determining pressing and tooling requirements for high density parts.
1
This test method is under the jurisdiction of ASTM Committee B09 on Metal Powders and Metal Powder Productsand is the direct responsibility of Subcommittee B09.02
on Base Metal Powders.
Current edition approved Oct. 1, 2010April 1, 2016. Published November 2010April 2016. Originally approved in 1958. Last previous edition approved in 20022010 as
B331 - 95B331(2002). DOI:10.1520/B0331-10. – 10. DOI:10.1520/B0331-16.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’sstandard’s Document Summary page on the ASTM website.
*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
1

---------------------- Page: 1 ----------------------
B331 − 16
5.4 Results may be affected by test conditions such as the type, amount, and method of lubrication, dwell time during
compaction, and die material. The compressibility values may not necessarily agree with results obtained under production
conditions.
6. Apparatus
6.1 Compacting Tooling—A cemented carbide die or alternatively, hardened tool steel die and two hardened steel punches
capable of producing the compressibility test specimen. The designs shown in Practice B925 for a cylindrical test specimen and
a transverse rupture test specimen are examples of acceptable tooling.
6.2 Powder Compacting Press—A compression testing machine or powder compacting press, capable of applying an adequate
load with an acc
...