ASTM B331-20

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 Units—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, health, and environmental 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.

General Information

• Status: Published
• Publication Date: 30-Sep-2020
• ICS: 77.160 - Powder metallurgy
• Technical Committee: B09 - Metal Powders and Metal Powder Products
• Drafting Committee: B09.02 - Base Metal Powders

Standards Content (Sample)

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.
Designation: B331 − 20
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* E456 Terminology Relating to Quality and Statistics
1.1 This laboratory test method covers the determination of
3. Terminology
the compressibility of metal powders and metal powder mix-
3.1 Definitions—For definitions of terms used in this test
tures as measured by the extent to which a test portion can be
method, refer toTerminology B243.Additional descriptive PM
densified under controlled conditions in a specified die.
information is available under General Information on PM on
1.2 Units—With the exception of the values for density and
the ASTM B09 web page.
3
mass, for which the use of gram per cubic centermetre (g/cm )
and gram (g) units is the longstanding industry practice, the
4. Summary of Test Method
values stated in inch-pound units are to be regarded as
4.1 Atest portion of metal powder is uniaxially compressed
standard. The values given in parentheses are mathematical
in a specific die under controlled conditions.
conversions to SI units that are provided for information only
4.2 The green density of the resulting compact is deter-
and are not considered standard.
mined.
1.3 This standard does not purport to address all of the
4.3 The compressibility of the powder is defined as the
safety concerns, if any, associated with its use. It is the
green density of the test compact at the compacting pressure
responsibility of the user of this standard to establish appro-
that was used.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
5. Significance and Use
1.4 This international standard was developed in accor-
5.1 The compressibility value obtained by this test is a
dance with internationally recognized principles on standard-
measure of a material characteristic of the powder.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
5.2 The test method is useful in research and development
mendations issued by the World Trade Organization Technical
projects, as a quality control test in the evaluation and
Barriers to Trade (TBT) Committee.
manufacturing control of metal powder production, and as an
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
6. Apparatus
6.1 Compacting Tooling—A cemented carbide die or
1
This test method is under the jurisdiction of ASTM Committee B09 on Metal
alternatively, hardened tool steel die and two hardened steel
Powders and Metal Powder Products and is the direct responsibility of Subcom-
mittee B09.02 on Base Metal Powders.
punches capable of producing the compressibility test speci-
Current edition approved Oct. 1, 2020. Published October 2020. Originally
men.ThedesignsshowninPracticesB925fora cylindrical test
approved in 1958. Last previous edition approved in 2016 as B331 – 16.
specimen and a transverse rupture test specimen are examples
DOI:10.1520/B0331-20.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or of acceptable tooling.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
6.2 Powder Compacting Press—A compression testing ma-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. chine or powder compacting press, capable of applying an
*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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...

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 − 16 B331 − 20
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 test portion can be densified under controlled conditions in a specified die.
3
1.2 Units—With the exception of the values for density and mass, for which the use of gram per cubic centermetre (g/cm ) 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 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
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 inunder the Related Material sectionGeneral Information on PM of Vol 02.05 of theon the ASTM B09
web Annual Book of ASTM Standards.page.
4. Summary of Test Method
4.1 A test portion of metal powder is uniaxially compressed in a specific die under controlled conditions.
1
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 April 1, 2016Oct. 1, 2020. Published April 2016October 2020. Originally approved in 1958. Last previous edition approved in 20102016 as
B331B331 – 16.– 10. DOI:10.1520/B0331-16. DOI:10.1520/B0331-20.
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’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 − 20
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.
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
...