ASTM E1558-09
(Guide)Standard Guide for Electrolytic Polishing of Metallographic Specimens
Standard Guide for Electrolytic Polishing of Metallographic Specimens
SIGNIFICANCE AND USE
Advantages of Electrolytic Polishing:
For some metals, a high quality surface finish can be produced that is equivalent to, or better than, that which can be obtained by mechanical methods.
Once procedures have been established, satisfactory results can be obtained rapidly with reproducibility.
There can be a marked saving of time if many specimens of the same material are polished sequentially.
Electropolishing a selected area on the surface of a relatively large metal part can be accomplished nondestructively, that is, without the need for sectioning to remove a piece.
Soft, single-phase metals, which may be difficult to polish by mechanical methods, may be successfully electropolished.
The true microstructure of a specimen can be obtained because artifacts (such as disturbed metal, scratches, and mechanical twins) produced on the surface, even by careful grinding and mechanical polishing operations, can be removed. These features are important in low-load hardness testing, X-ray diffraction studies, and in electron microscopy, where higher resolution puts a premium on undistorted metal surfaces.
After electropolishing is completed, etching can often be accomplished by reducing the voltage (generally to about one-tenth that required for polishing) for a short time before it is turned off.
Note 2—Not all electropolishing solutions produce good etching results.
Disadvantages of Electrolytic Polishing:
Many of the chemical mixtures used in electropolishing are poisonous or dangerous if not properly handled (see Section 5). These hazards are similar to those involved in the mixing and handling of etchants, see Test Methods E 407.
In multi-phase alloys, the polishing rate of each phase may be different. The result may be a non-planar surface.
Electropolished surfaces may be slightly undulated rather than perfectly planar and, therefore, may not be suitable for examination at all magnifications.
The rate of polishing in areas adjacent to var...
SCOPE
1.1 This guide deals with electrolytic polishing as a means of preparation of specimens for metallographic purposes. Procedures are described for polishing a variety of metals.
Note 1—References (1-133) on electrolytic polishing will provide the reader with specific information beyond the scope of this guide.
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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 and health practices and determine the applicability of regulatory limitations prior to use. Specific safety precautions are described in Section 5 and 6.3.1.
General Information
Relations
Buy Standard
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E1558 − 09
StandardGuide for
1
Electrolytic Polishing of Metallographic Specimens
This standard is issued under the fixed designation E1558; 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.
1. Scope 4.1.1 For some metals, a high quality surface finish can be
producedthatisequivalentto,orbetterthan,thatwhichcanbe
1.1 This guide deals with electrolytic polishing as a means
obtained by mechanical methods.
of preparation of specimens for metallographic purposes.
4.1.2 Once procedures have been established, satisfactory
Procedures are described for polishing a variety of metals.
results can be obtained rapidly with reproducibility.
2
NOTE 1—References (1-133) on electrolytic polishing will provide the
4.1.3 There can be a marked saving of time if many
reader with specific information beyond the scope of this guide.
specimens of the same material are polished sequentially.
1.2 The values stated in SI units are to be regarded as
4.1.4 Electropolishing a selected area on the surface of a
standard. No other units of measurement are included in this
relatively large metal part can be accomplished
standard.
nondestructively, that is, without the need for sectioning to
1.3 This standard does not purport to address all of the
remove a piece.
safety concerns, if any, associated with its use. It is the
4.1.5 Soft, single-phase metals, which may be difficult to
responsibility of the user of this standard to establish appro-
polish by mechanical methods, may be successfully electrop-
priate safety and health practices and determine the applica-
olished.
bility of regulatory limitations prior to use. Specific safety
4.1.6 Thetruemicrostructureofaspecimencanbeobtained
precautions are described in Section 5 and 6.3.1.
because artifacts (such as disturbed metal, scratches, and
mechanical twins) produced on the surface, even by careful
2. Referenced Documents
grindingandmechanicalpolishingoperations,canberemoved.
3
2.1 ASTM Standards:
These features are important in low-load hardness testing,
E7Terminology Relating to Metallography
X-ray diffraction studies, and in electron microscopy, where
E407Practice for Microetching Metals and Alloys
higher resolution puts a premium on undistorted metal sur-
faces.
3. Terminology
4.1.7 After electropolishing is completed, etching can often
3.1 Definitions—All terms used in this guide are either
be accomplished by reducing the voltage (generally to about
defined in Terminology E7 or are discussed in 3.2.
one-tenth that required for polishing) for a short time before it
is turned off.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 electrolytic polish (electropolish)—A method of pol-
NOTE 2—Not all electropolishing solutions produce good etching
ishingmetalsandalloysinwhichmaterialisremovedfromthe
results.
surface by making the metal the anode in an electrolytic bath.
4.2 Disadvantages of Electrolytic Polishing:
4.2.1 Many of the chemical mixtures used in electropolish-
4. Significance and Use
ing are poisonous or dangerous if not properly handled (see
4.1 Advantages of Electrolytic Polishing:
Section 5). These hazards are similar to those involved in the
mixing and handling of etchants, see Test Methods E407.
4.2.2 In multi-phase alloys, the polishing rate of each phase
1
ThisguideisunderthejurisdictionofASTMCommitteeE04onMetallography
may be different. The result may be a non-planar surface.
and is the direct responsibility of Subcommittee E04.01 on Specimen Preparation.
Current edition approved May 1, 2009. Published June 2009. Originally
4.2.3 Electropolished surfaces may be slightly undulated
approved in 1993. Last previous edition approved in 2004 as E1558–99(2004).
rather than perfectly planar and, therefore, may not be suitable
DOI: 10.1520/E1558-09.
for examination at all magnifications.
2
The boldface numbers in parentheses refer to the references at the end of this
standard.
4.2.4 The rate of polishing in areas adjacent to various
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
inhomogeneities, such as nonmetallic inclusions and voids, is
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
usuallygreaterthanthatinthesurroundingmatrixandtendsto
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. exaggerate the size of the inclusions and voids.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
E1558 − 09
4.2.5 Dimples, pits, and waviness limit appli
...
This document is not anASTM standard and is intended only to provide the user of anASTM 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:E1558–99 (Reapproved 2004) Designation:E1558–09
Standard Guide for
1
Electrolytic Polishing of Metallographic Specimens
This standard is issued under the fixed designation E1558; 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.
1. Scope
1.1 Thisguidedealswithelectrolyticpolishingasameansofpreparationofspecimensformetallographicpurposes.Procedures
are described for polishing a variety of metals.
2
NOTE 1—References (1-133) on electrolytic polishing will provide the reader with specific information beyond the scope of this guide.
1.2
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this 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 and health practices and determine the applicability of regulatory
limitations prior to use. Specific safety precautions are described in Section 5 and 6.3.1.
2. Referenced Documents
3
2.1 ASTM Standards:
E7 Terminology Relating to Metallography
E407 Test MethodsPractice for Microetching Metals and Alloys
3. Terminology
3.1 Definitions—All terms used in this guide are either defined in Terminology E7 or are discussed in 3.2.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 electrolytic polish (electropolish)—Amethodofpolishingmetalsandalloysinwhichmaterialisremovedfromthesurface
by making the metal the anode in an electrolytic bath.
4. Significance and Use
4.1 Advantages of Electrolytic Polishing:
4.1.1 For some metals, a high quality surface finish can be produced that is equivalent to, or better than, that which can be
obtained by mechanical methods.
4.1.2 Once procedures have been established, satisfactory results can be obtained rapidly with reproducibility.
4.1.3 There can be a marked saving of time if many specimens of the same material are polished sequentially.
4.1.4 Electropolishing a selected area on the surface of a relatively large metal part can be accomplished nondestructively, that
is, without the need for sectioning to remove a piece.
4.1.5 Soft, single-phase metals, which may be difficult to polish by mechanical methods, may be successfully electropolished.
4.1.6 The true microstructure of a specimen can be obtained because artifacts (such as disturbed metal, scratches, and
mechanicaltwins)produced on the surface, even bycarefulgrindingandmechanicalpolishingoperations,canberemoved.These
features are important in low-load hardness testing, X-ray diffraction studies, and in electron microscopy, where higher resolution
puts a premium on undistorted metal surfaces.
4.1.7 After electropolishing is completed, etching can often be accomplished by reducing the voltage (generally to about
one-tenth that required for polishing) for a short time before it is turned off.
NOTE 2—Not all electropolishing solutions produce good etching results.
4.2 Disadvantages of Electrolytic Polishing:
1
This guide is under the jurisdiction of ASTM Committee E04 on Metallography and is the direct responsibility of Subcommittee E04.01 on Specimen Preparation .
Current edition approved JuneMay 1, 2004.2009. Published July 2004.June 2009. Originally approved in 1993. Last previous edition approved in 19992004 as
E1558–99(2004).
2
The boldface numbers in parentheses refer to the references at the end of this standard.
3
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatservice@astm.org.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 ----------------------
E1558–09
4.2.1 Many of the chemical mixtures used in electropolishing are poisonous or dangerous if not properly handled (see Section
5). These hazards are similar to those involved in the mixing and handling of etchants, see Test Methods E407.
4.2.2 In multi-phase alloys, the polishing rate of each phase may be different. The result may be a non-planar surface.
4.2.3 Electropolished surfaces may be slightly undulated rather than perfectly planar and, therefore, may not be suitab
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.