ASTM B665-08(2012)
(Guide)Standard Guide for Metallographic Sample Preparation of Cemented Tungsten Carbides
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 Test Method B657 and Practice B390. 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 and health practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: B665 − 08 (Reapproved 2012)
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* section as possible. For micrographs, the area selected should
represent, as nearly as possible, the entire cross section.
1.1 This guide prescribes a method for preparing cemented
carbides for metallographic examination.
5. Procedure
1.2 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
5.1 There are several acceptable methods for preparing
responsibility of the user of this standard to establish appro-
cemented tungsten carbide surfaces for microscopical exami-
priate safety and health practices and determine the applica-
nation. Basically, they all use diamond wheels for grinding and
bility of regulatory limitations prior to use.
diamond powders for lapping. The grinding practices differ, to
a minor degree, with respect to grit size of diamond. In all
2. Referenced Documents
practices, however, the final polish is produced by extremely
2.1 ASTM Standards:
fine diamond powder lapping, and in all practices care must be
B390 Practice for Evaluating Apparent Grain Size and Dis-
exercised to retain the microstructure in its true form and to
tribution of Cemented Tungsten Carbides (Withdrawn
avoid pull-out of the softer matrix material (usually cobalt).
2010)
While it is accepted that other procedures may be used
B657 Guide for Metallographic Identification of Microstruc-
successfully, this procedure has proved satisfactory in many
ture in Cemented Carbides
laboratories.
5.1.1 Mounting—Where possible, specimens should be
3. Significance and Use
mounted in a plastic material such as phenol-formaldehyde or
3.1 This sample preparation procedure may be used to
poly(methyl methacrylate) to facilitate polishing without
prepare metallographic samples for Test Method B657 and
rounding the edges. Larger specimens may be polished without
Practice B390. It does not include all variations of sample
mounting. When specimens are too large they may be sec-
preparation.
tioned using a diamond cut-off wheel or they may be fractured
(appropriate safety precautions should be used when fracturing
4. Selection of Specimen
specimens). The area selected for examination should
4.1 Cemented tungsten carbides are very often in the form
represent, as nearly as possible, the entire cross section.
of relatively small pieces; it is possible to select and mount the
5.1.2 Rough Grinding—The surface to be examined may be
entire piece in such manner as to permit examination of the
ground flat on a surface grinder with a resin-bonded diamond
entire cross section. When pieces are too large for this,
wheel (100 to 220 grit) operated at 5000 to 5500 surface feet
however, they should be sectioned, using a diamond cutoff
wheel, to allow viewing as much of a representative cross per minute (25 to 28 m/s). After the 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
This guide is under the jurisdiction of ASTM Committee B09 on Metal
should be used.
Powders and Metal Powder Productsand is the direct responsibility of Subcommit-
5.1.3 Polishing—Polishing in three steps using diamond
tee B09.06 on Cemented Carbides.
Current edition approved
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