ASTM B933-20

Standard Test Method for Microindentation Hardness of Powder Metallurgy (PM) Materials

SIGNIFICANCE AND USE
5.1 Microindentation hardness testing provides a measure of the hardness of the microstructural constituents of a porous material. It indicates the hardness the material would have if there were no pores present and the material was tested using macroindentation hardness methods. Loads are limited to a maximum of 200 gf to reduce the likelihood of interference from the porosity.  
5.2 Microindentation hardness tests allow the evaluation of specific phases, microstructural constituents, and regions or gradients too small for macroindentation hardness testing.
SCOPE
1.1 This test method covers the determination of the microindentation hardness of powder metallurgy (PM) materials. The test method differs from the approach used for pore-free materials in terms of the precautions required to deal with the porosity.  
1.2 This procedure covers tests made with the Knoop or Vickers indenters under loads in the range from 1 to 200 gf.  
1.3 Automated testing is not generally suitable for use with porous PM materials, because acceptable indentations require avoiding placing indentations in the immediate vicinity of a pore, a condition not guaranteed with automated placement of the indentations. Any automated testing shall allow for review of indentations post-test to reject any distorted or unusually large indentations in accordance with 9.4.  
1.4 A method for converting the directly measured indentation lengths to other hardness scales, for example, HRC is described in Appendix X1.  
1.5 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.  
1.6 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: B09.05 - Structural Parts

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: B933 − 20
Standard Test Method for
Microindentation Hardness of Powder Metallurgy (PM)
1
Materials
This standard is issued under the fixed designation B933; 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* 2. Referenced Documents
2
2.1 ASTM Standards:
1.1 This test method covers the determination of the micro-
B243 Terminology of Powder Metallurgy
indentation hardness of powder metallurgy (PM) materials.
E384 Test Method for Microindentation Hardness of Mate-
The test method differs from the approach used for pore-free
rials
materials in terms of the precautions required to deal with the
E691 Practice for Conducting an Interlaboratory Study to
porosity.
Determine the Precision of a Test Method
3
1.2 This procedure covers tests made with the Knoop or
2.2 MPIF Standards:
Vickers indenters under loads in the range from 1 to 200 gf.
Standard70 GuidetoSamplePreparationofFerrousPowder
Metallurgy (PM) Materials for Cross-Sectional Metallo-
1.3 Automated testing is not generally suitable for use with
graphic Evaluation
porous PM materials, because acceptable indentations require
Standard 71 Guide to Sample Preparation of Copper-Based
avoiding placing indentations in the immediate vicinity of a
Powder Metallurgy (PM) Materials for Cross-Sectional
pore, a condition not guaranteed with automated placement of
Metallographic Evaluation
the indentations.Any automated testing shall allow for review
Standard 72 Guide to Sample Preparation of Aluminum
of indentations post-test to reject any distorted or unusually
Powder Metallurgy (PM) Materials for Cross-Sectional
large indentations in accordance with 9.4.
Metallographic Evaluation
1.4 Amethod for converting the directly measured indenta-
3. Terminology
tion lengths to other hardness scales, for example, HRC is
3.1 Definitions of powder metallurgy (PM) terms can be
described in Appendix X1.
found in Terminology B243. Additional descriptive informa-
1.5 This standard does not purport to address all of the
tion is available under General Information on PM on the
safety concerns, if any, associated with its use. It is the
ASTM B09 web page.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter- 4. Summary of Test Method
mine the applicability of regulatory limitations prior to use.
4.1 Microindentation hardness testing uses a calibrated
1.6 This international standard was developed in accor-
machine to force a pyramidal-pointed diamond indenter into
dance with internationally recognized principles on standard-
the surface of the test material under a known test load. The
ization established in the Decision on Principles for the
microindentation hardness value is calculated from the indent-
Development of International Standards, Guides and Recom-
ing force divided by the projected area of the resulting
mendations issued by the World Trade Organization Technical indentation.
Barriers to Trade (TBT) Committee. NOTE 1—This test method is designed specifically for use on porous
PM materials. It is intended to be a companion to Test Method E384.
There are specific differences that are intentional, such as restricting the
applied load to a maximum of 200 gf; otherwise, the details on equipment
and procedures in Test Method E384 shall be adhered to. The specific
differences relate to the presence of porosity in the PM materials. Special
1 2
This test method is under the jurisdiction of ASTM Committee B09 on Metal For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Powders and Metal Powder Products and is the direct responsibility of Subcom- contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
mittee B09.05 on Structural Parts. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Oct. 1, 2020. Published October 2020. Originally the ASTM website.
3
approved in 2004. Last previous edition approved in 2016 as B933 – 16. DOI: Available from Metal Powder Industries Federation (MPIF), 105 College Rd.
10.1520/B0933-20. East, Princeton, NJ 08540, 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
1

---------------------- Page: 1 ----------------------
B933 − 20
precautions are required during samp
...

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: B933 − 16 B933 − 20
Standard Test Method for
Microindentation Hardness of Powder Metallurgy (PM)
1
Materials
This standard is issued under the fixed designation B933; 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 the determination of the microindentation hardness of powder metallurgy (PM) materials. The test
method differs from the approach used for pore-free materials in terms of the precautions required to deal with the porosity.
1.2 This procedure covers tests made with the Knoop or Vickers indenters under loads in the range from 1 to 200 gf.
1.3 Automated testing is not generally suitable for use with porous PM materials, because acceptable indentations require avoiding
placing indentations in the immediate vicinity of a pore, a condition not guaranteed with automated placement of the indentations.
Any automated testing shall allow for review of indentations post-test to reject any distorted or unusually large indentations in
accordance with 9.4.
1.4 A method for converting the directly measured indentation lengths to other hardness scales, for example, HRC is described
in Appendix X1.
1.5 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.
1.6 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:
B243 Terminology of Powder Metallurgy
E384 Test Method for Microindentation Hardness of Materials
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3
2.2 MPIF Standards:
Standard 70 Guide to Sample Preparation of Ferrous Powder Metallurgy (PM) Materials for Cross-Sectional Metallographic
Evaluation
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 B09.05
on Structural Parts.
Current edition approved April 1, 2016Oct. 1, 2020. Published April 2016October 2020. Originally approved in 2004. Last previous edition approved in 20142016 as B933
– 14.16. DOI: 10.1520/B0933-16.10.1520/B0933-20.
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.
3
Available from Metal Powder Industries Federation (MPIF), 105 College Rd. East, Princeton, NJ 08540, 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
1

---------------------- Page: 1 ----------------------
B933 − 20
Standard 71 Guide to Sample Preparation of Copper-Based Powder Metallurgy (PM) Materials for Cross-Sectional Metallo-
graphic Evaluation
Standard 72 Guide to Sample Preparation of Aluminum Powder Metallurgy (PM) Materials for Cross-Sectional Metallographic
Evaluation
3. Terminology
3.1 Definitions of powder metallurgy (PM) terms can be found in Terminology B243. Additional descriptive information is
available inunder the Related Materials 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 Microindentation hardness testing uses a calibrated machine to force a pyramidal-pointed diamond indenter into the surface
of the test material under a known test load. The microindentation hardness value is calculated from the indenting force divided
by the projected area of the resulting indentation.
NOTE 1—This test method is designed specifically for use on porous PM materials. It is intended to be a companion to Test Method E384. There are
specific differences that are intentional, such as restrictin
...