ASTM B665-19

Standard Guide for Metallographic Sample Preparation of Cemented Tungsten Carbides

SIGNIFICANCE AND USE
3.1 This sample preparation procedure may be used to prepare metallographic samples for Guide B657. It does not include all variations of sample preparation.
SCOPE
1.1 This guide prescribes a method for preparing cemented carbides for metallographic examination.  
1.2 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.  
1.3 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: 31-Oct-2019
• ICS: 77.160 - Powder metallurgy
• Technical Committee: B09 - Metal Powders and Metal Powder Products
• Drafting Committee: B09.06 - Cemented Carbides

Relations

• Replaces: ASTM B665-08(2012) - Standard Guide for Metallographic Sample Preparation of Cemented Tungsten Carbides
• Effective Date: 01-Nov-2019
• Refers: ASTM B657-11 - Guide for Metallographic Identification of Microstructure in Cemented Carbides
• Effective Date: 01-Oct-2011
• Refers: ASTM B657-05 - Guide for Metallographic Identification of Microstructure in Cemented Carbides
• Effective Date: 01-Oct-2005
• Refers: ASTM B657-92(1996)e1 - Standard Test Method for Metallographic Determination of Microstructure in Cemented Tungsten Carbides
• Effective Date: 01-Jan-2000
• Refers: ASTM B657-92(2000) - Standard Test Method for Metallographic Determination of Microstructure in Cemented Tungsten Carbides
• Effective Date: 01-Jan-2000
• Referred By: ASTM B657-23 - Standard Guide for Metallographic Identification of Microstructure in Cemented Carbides
• Effective Date: 01-Nov-2019
• Referred By: ASTM B276-21 - Standard Test Method for Apparent Porosity in Cemented Carbides
• Effective Date: 01-Nov-2019
• Referred By: ASTM B930-03(2021) - Standard Test Method for Rating Grain Size and Frequency of Abnormally Large Grains in Cemented Tungsten Carbides (Hardmetals)
• Effective Date: 01-Nov-2019

Overview

ASTM B665-19: Standard Guide for Metallographic Sample Preparation of Cemented Tungsten Carbides describes established procedures for preparing cemented carbide samples for metallographic examination. This guide ensures reliable assessment of microstructure characteristics in cemented tungsten carbides, vital for quality control, research, and failure analysis in industrial applications. Developed by ASTM International, this standard outlines steps for mounting, grinding, and polishing specimens to preserve microstructural integrity. Compliance with this guide enables consistent preparation outcomes, supports comparability of results, and promotes safety and regulatory awareness.

Key Topics

• Scope and Applicability

  • Prescribes methods for preparing cemented tungsten carbides for metallographic analysis.
  • Recommended for use with other guides, such as ASTM B657 for microstructure identification.
  • Addresses general procedures but recognizes that other successful methods may be used.
  • Emphasizes user responsibility to adhere to safety, health, and environmental regulations.

• Sample Selection and Mounting

  • Suitable for both small and large cemented carbide specimens; small parts can be mounted entirely, while larger ones require sectioning using a diamond cut-off wheel or electrical discharge machining (EDM).
  • Mounting in plastics (e.g., phenol-formaldehyde or poly(methyl methacrylate)) facilitates easier handling and edge retention during polishing.

• Grinding and Polishing Procedures

  • Outlines multiple-step grinding using diamond wheels and careful surface preparation to remove cutting damage.
  • Stresses the use of incremental grit sizes and controlled conditions to avoid altering or damaging the material’s microstructure.
  • Final polishing employs extremely fine diamond powder or diamond impregnated polymer film, preserving true structural detail and preventing matrix material pull-out.

• Best Practices

  • Use of adequate pressure and thorough cleaning between steps is essential, with ultrasonic cleaning recommended to eliminate contaminants.
  • Both manual and automated polishing equipment are supported, allowing flexibility based on laboratory resources.

Applications

The procedures in ASTM B665-19 are widely used across industries and research institutions working with cemented tungsten carbides. Principal applications include:

• Quality Assurance
  Consistent sample preparation is essential for process monitoring and product validation in carbide manufacturing.

• Process Development and Research
  Researchers utilize standardized techniques to compare microstructural changes resulting from new manufacturing processes or treatments.

• Failure Analysis
  Accurate preparation preserves critical evidence within carbide components, supporting investigations into operational failures and improving reliability.

• Education and Training
  The guide serves as a foundational reference for teaching metallographic techniques involving hard, wear-resistant carbides.

Related Standards

For thorough and consistent results, ASTM B665-19 should be used in conjunction with the following standards:

• ASTM B657 – Guide for Metallographic Identification of Microstructure in Cemented Carbides
  Offers techniques for analyzing and classifying the microstructure of prepared samples.

• ASTM B390 – Practice for Evaluating Apparent Grain Size and Distribution of Cemented Tungsten Carbides (Withdrawn 2010)
  Historically referenced for grain size evaluation in carbide materials.

Users of ASTM B665-19 are encouraged to refer to the most up-to-date versions of relevant standards and to adopt best practices for laboratory safety and regulatory compliance. For purchasing standards and accessing additional guidance, visit the ASTM International website.

By following ASTM B665-19, organizations ensure that metallographic sample preparation of cemented tungsten carbides is consistent, reproducible, and aligned with internationally recognized methodologies.

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: B665 − 19
Standard Guide for
Metallographic Sample Preparation of Cemented Tungsten
Carbides
This standard is issued under the fixed designation B665; 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* viewing of as much of a representative cross section as
possible. For micrographs, the area selected should represent,
1.1 This guide prescribes a method for preparing cemented
as nearly as possible, the entire cross section.
carbides for metallographic examination.
1.2 This standard does not purport to address all of the
5. Procedure
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
5.1 There are several acceptable methods for preparing
priate safety, health, and environmental practices and deter-
cemented tungsten carbide surfaces for microscopical exami-
mine the applicability of regulatory limitations prior to use.
nation. Basically, they all use diamond wheels for grinding and
1.3 This international standard was developed in accor-
diamond powders for lapping. The grinding practices differ, to
dance with internationally recognized principles on standard-
a minor degree, with respect to grit size of diamond. In all
ization established in the Decision on Principles for the
practices, however, the final polish is produced by extremely
Development of International Standards, Guides and Recom-
fine diamond powder lapping, and in all practices care must be
mendations issued by the World Trade Organization Technical
exercised to retain the microstructure in its true form and to
Barriers to Trade (TBT) Committee.
avoid pull-out of the softer matrix material (usually cobalt).
While it is accepted that other procedures may be used
2. Referenced Documents
successfully, this procedure has proved satisfactory in many
2.1 ASTM Standards:
laboratories.
B657 Guide for Metallographic Identification of Microstruc-
5.1.1 Mounting—Where possible, specimens should be
ture in Cemented Carbides
mounted in a plastic material such as phenol-formaldehyde or
poly(methyl methacrylate) to facilitate polishing without
3. Significance and Use
rounding the edges. Larger specimens may be polished without
3.1 This sample preparation procedure may be used to
mounting. When specimens are too large, they may be sec-
prepare metallographic samples for Guide B657. It does not
tioned using a diamond cut-off wheel or they may be fractured
include all variations of sample preparation.
(appropriate safety precautions should be used when fracturing
specimens). The area selected for examination should
4. Selection of Specimen
represent, as nearly as possible, the entire cross section.
4.1 Cemented tungsten carbides are very often in the form
5.1.2 Rough Grinding—The surface to be examined may
of relatively small pieces; it is possible to select and mount the
require removal of surface damage from EDM or cutting.
entire piece in such manner as to permit examination of the
Specimens shall be ground flat utilizing a surface grinder with
entire cross section. When pieces are too large for this,
a resin-bonded diamond wheel (100 to 220 grit) operated at
however, they should be sectioned, using a diamond cutoff
4000 to 6000 surface feet per minute (20 to 30 m⁄s). After the
wheel or electrical discharge machining (EDM), to allow
surface is flat, several clean-up passes are required; the
maximum depth of cut should be 0.0005 in. (13 µm) per pass
and copious amounts of coolant should be used.
This guide is under the jurisdiction of ASTM Committee B09 on Metal
Powders and Metal Powder Products and is the direct responsibility of Subcom-
5.1.3 Polishing—Polish in three steps using diamond pow-
mittee B09.06 on Cemented Carbides.
der with the addition of a lubricant, paste, or a commercially
Current edition approved Nov. 1, 2019. Published November 2019. Originally
prepared
...

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: B665 − 08 (Reapproved 2012) B665 − 19
Standard Guide for
Metallographic Sample Preparation of Cemented Tungsten
Carbides
This standard is issued under the fixed designation B665; 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 guide prescribes a method for preparing cemented carbides for metallographic examination.
1.2 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.
1.3 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:
B390 Practice for Evaluating Apparent Grain Size and Distribution of Cemented Tungsten Carbides (Withdrawn 2010)
B657 Guide for Metallographic Identification of Microstructure in Cemented Carbides
3. Significance and Use
3.1 This sample preparation procedure may be used to prepare metallographic samples for Test Method Guide B657 and
Practice B390. It does not include all variations of sample preparation.
4. Selection of Specimen
4.1 Cemented tungsten carbides are very often in the form of relatively small pieces; it is possible to select and mount the entire
piece in such manner as to permit examination of the entire cross section. When pieces are too large for this, however, they should
be sectioned, using a diamond cutoff wheel, wheel or electrical discharge machining (EDM), to allow viewing of as much of a
representative cross section as possible. For micrographs, the area selected should represent, as nearly as possible, the entire cross
section.
5. Procedure
5.1 There are several acceptable methods for preparing cemented tungsten carbide surfaces for microscopical examination.
Basically, they all use diamond wheels for grinding and diamond powders for lapping. The grinding practices differ, to a minor
degree, with respect to grit size of diamond. In all practices, however, the final polish is produced by extremely fine diamond
powder lapping, and in all practices care must be exercised to retain the microstructure in its true form and to avoid pull-out of
the softer matrix material (usually cobalt). While it is accepted that other procedures may be used successfully, this procedure has
proved satisfactory in many laboratories.
5.1.1 Mounting—Where possible, specimens should be mounted in a plastic material such as phenol-formaldehyde or
poly(methyl methacrylate) to facilitate polishing without rounding the edges. Larger specimens may be polished without mounting.
This guide is under the jurisdiction of ASTM Committee B09 on Metal Powders and Metal Powder Products and is the direct responsibility of Subcommittee B09.06
on Cemented Carbides.
Current edition approved Oct. 1, 2012Nov. 1, 2019. Published October 2012November 2019. Originally approved in 1979. Last previous edition approved in 20082012
as B665B665 – 08–08.(2012). DOI: 10.1520/B0665-08R12.10.1520/B0665-19.
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
B665 − 19
When specimens are too large, they may be sectioned using a diamond cut-off wheel or they may be fractured (appropriate safety
precautions should be used when fracturing specimens). The area selected for examination should represent, as nearly as possible,
the entire cross section.
5.1.2 Rough Grinding—The surface to be examined may requ
...