ASTM E1558-09(2014)
Standard Guide for Electrolytic Polishing of Metallographic Specimens

Standard No.

ASTM E1558-09(2014)

Release Date

2009

Published By

American Society for Testing and Materials (ASTM)

Status

Be replaced

Replace By

ASTM E1558-09(2021)

Latest

ASTM E1558-09(2021)

Scope

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 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.

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: 

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 suitable for examination at all magnifications.

4.2.4 The rate of polishing in areas adjacent to various inhomogeneities, such as nonmetallic inclusions and voids, is usually greater than that in the surrounding matrix and tends to exaggerate the size of the inclusions and voids.

4.......

ASTM E1558-09(2014) Referenced Document

• ASTM E407 Standard Practice for Microetching Metals and Alloys
• ASTM E7 Standard Terminology Relating to Metallography

ASTM E1558-09(2014) history

• 2021 ASTM E1558-09(2021) Standard Guide for Electrolytic Polishing of Metallographic Specimens
• 2009 ASTM E1558-09(2014) Standard Guide for Electrolytic Polishing of Metallographic Specimens
• 2009 ASTM E1558-09 Standard Guide for Electrolytic Polishing of Metallographic Specimens
• 1999 ASTM E1558-99(2004) Standard Guide for Electrolytic Polishing of Metallographic Specimens
• 1999 ASTM E1558-99 Standard Guide for Electrolytic Polishing of Metallographic Specimens