ASTM B487-20

Standard Test Method for Measurement of Metal and Oxide Coating Thickness by Microscopical Examination of Cross Section

SIGNIFICANCE AND USE
4.1 Coating thickness is an important factor in the performance of a coating in service and is usually specified in a coating specification.  
4.2 This method is suitable for acceptance testing.
SCOPE
1.1 This test method covers measurement of the local thickness of metal and oxide coatings by the microscopical examination of cross sections using an optical microscope.  
1.2 Under good conditions, when using an optical microscope, the method is capable of giving an absolute measuring accuracy of 0.8 μm. Accuracy will determine the suitability of the method for measuring the thickness of thin coatings. Accuracy is dependent upon the setup of the microscope and preparation of the sample; 0.8 μm should not be taken as an absolute and instead as guideline.  
1.2.1 Optical microscopes may use digital image capture devices and software to evaluate those images.  
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. (This is especially applicable to the chemicals cited in Table X2.1.)  
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: 31-Oct-2020
• ICS: 17.040.20 - Properties of surfaces
• Technical Committee: B08 - Metallic and Inorganic Coatings
• Drafting Committee: B08.10 - Test Methods

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: B487 − 20
Standard Test Method for
Measurement of Metal and Oxide Coating Thickness by
1
Microscopical Examination of Cross Section
This standard is issued under the fixed designation B487; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 3. Summary of Test Method
1.1 This test method covers measurement of the local
3.1 This test method consists of cutting out a portion of the
thickness of metal and oxide coatings by the microscopical test specimen, mounting it, and preparing the mounted cross
examination of cross sections using an optical microscope. section by suitable techniques of grinding, polishing, and
etching.Thethicknessofthecrosssectionismeasuredwithan
1.2 Under good conditions, when using an optical
optical microscope.
microscope, the method is capable of giving an absolute
measuring accuracy of 0.8µm. Accuracy will determine the
NOTE 1—These techniques will be familiar to experienced
metallographers,butsomeguidanceisgiveninSection5andinAppendix
suitability of the method for measuring the thickness of thin
X1 for less experienced operators.
coatings. Accuracy is dependent upon the setup of the micro-
scope and preparation of the sample; 0.8 µm should not be
4. Significance and Use
taken as an absolute and instead as guideline.
1.2.1 Optical microscopes may use digital image capture
4.1 Coating thickness is an important factor in the perfor-
devices and software to evaluate those images. mance of a coating in service and is usually specified in a
coating specification.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4.2 This method is suitable for acceptance testing.
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
5. Factors Influencing the Measurement Result
mine the applicability of regulatory limitations prior to use.
5.1 Surface Roughness—If the coating or its substrate has a
(This is especially applicable to the chemicals cited in Table
rough surface, one or both of the interfaces bounding the
X2.1.)
coating cross section may be too irregular to permit accurate
1.4 This international standard was developed in accor-
measurement. (See X1.4.)
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the 5.2 Taper of Cross Section—Iftheplaneofthecrosssection
is not perpendicular to the plane of the coating, the measured
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical thickness will be greater than the true thickness. For example,
an inclination of 10° to the perpendicular will contribute a
Barriers to Trade (TBT) Committee.
1.5% error.
2. Referenced Documents
5.3 Deformation of the Coating—Detrimental deformation
2
2.1 ASTM Standards: of the coating can be caused by excessive temperature or
pressure during mounting and preparation of cross sections of
E3Guide for Preparation of Metallographic Specimens
soft coatings or coatings melting at low temperatures, and also
by excessive abrasion of brittle materials during preparation of
cross sections.
1
ThistestmethodisunderthejurisdictionofASTMCommitteeB08onMetallic
and Inorganic Coatings and is the direct responsibility of Subcommittee B08.10 on
5.4 Rounding of Edge of Coating—Iftheedgeofthecoating
Test Methods.
cross section is rounded, that is, if the coating cross section is
Current edition approved Nov. 1, 2020. Published November 2020. Originally
notcompletelyflatuptoitsedges,thetruethicknesscannotbe
approvedin1968.Lastpreviouseditionapprovedin2013asB487–85(2013).DOI:
10.1520/B0487-20.
observed microscopically. Edge rounding can be caused by
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
improper mounting, grinding, polishing, or etching. It is
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
usually minimized by overplating the test specimen before
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. mounting. (See X1.2.)
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
B487 − 20
5.5 Overplatin
...

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: B487 − 85 (Reapproved 2013) B487 − 20
Standard Test Method for
Measurement of Metal and Oxide Coating Thickness by
1
Microscopical Examination of Cross Section
This standard is issued under the fixed designation B487; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope
1.1 This test method covers measurement of the local thickness of metal and oxide coatings by the microscopical examination of
cross sections using an optical microscope.
1.2 Under good conditions, when using an optical microscope, the method is capable of giving an absolute measuring accuracy
of 0.8 μm. This 0.8 μm. Accuracy will determine the suitability of the method for measuring the thickness of thin coatings.
Accuracy is dependent upon the setup of the microscope and preparation of the sample; 0.8 μm should not be taken as an absolute
and instead as guideline.
1.2.1 Optical microscopes may use digital image capture devices and software to evaluate those images.
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. (This is especially applicable to the chemicals cited in Table X2.1.)
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:
E3 Guide for Preparation of Metallographic Specimens
3. Summary of Test Method
3.1 This test method consists of cutting out a portion of the test specimen, mounting it, and preparing the mounted cross section
by suitable techniques of grinding, polishing, and etching. The thickness of the cross section is measured with an optical
microscope.
1
This test method is under the jurisdiction of ASTM Committee B08 on Metallic and Inorganic Coatings and is the direct responsibility of Subcommittee B08.10 on Test
Methods.
Current edition approved Dec. 1, 2013Nov. 1, 2020. Published December 2013November 2020. Originally approved in 1968. Last previous edition approved in 20072013
as B487 – 85 (2007).(2013). DOI: 10.1520/B0487-85R13.10.1520/B0487-20.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
B487 − 20
NOTE 1—These techniques will be familiar to experienced metallographers, but some guidance is given in Section 5 and in Appendix X1 for less
experienced operators.
4. Significance and Use
4.1 Coating thickness is an important factor in the performance of a coating in service and is usually specified in a coating
specification.
4.2 This method is suitable for acceptance testing.
5. Factors Influencing the Measurement Result
5.1 Surface Roughness—If the coating or its substrate has a rough surface, one or both of the interfaces bounding the coating cross
section may be too irregular to permit accurate measurement. (See X1.4).)
5.2 Taper of Cross Section—If the plane of the cross section is not perpendicular to the plane of the coating, the measured thickness
will be greater than the true thickness. For example, an inclination of 10° to the perpendicular will contribute a 1.5 % error.
5.3 Deformation of the Coating—Detrimental deformation of the coating can be caused by excessive temperature or pressure
during mounting and preparation of cross sections of soft coatings or coatings melting at low temperatures, and also by excessive
abrasion of brittle materials during preparation of cross sections.
5.4 Rounding of Edge of Coating—If the edge of the coating cross section is rounded, that is, if the coati
...