Why is understanding sample preparation
. . . do I have to have a met lab . . . Where
can I find color etching metallography examples?
- It is important to understand metallographic sample
preparation in order to preserve important features
and not destroy/alter any that may be needed later.
- Large suppliers, and many smaller niche suppliers,
of met lab equipment and materials will provide training
and advice on sample preparation, including:
- Buehler, Lake Bluff, IL
- Leco, St. Joseph, MI
- Struers, Westlake, OH
- If an inhouse "met lab" is unavailable, many labs can
do this. If a lab is used, it is very important to describe
specifically what you want from the specimen.
- Mount, polish, etch procedures can get very specific,
depending on specimen material -- metal (hard/soft),
ceramic composite -- and information desired.
- Etching reveals features by improving contrast, showing
different height differences, and sometimes staining and/or
coloring different phases.
- "Relief polishing" using 0.1 micron alumina or
diamond can eliminate need for etching.
- Sample preparation procedures must be considered along
with viewing procedures - AFM, SEM, visible light, etc.
Excellent references are available, including:
- "The Metalog Guide," L. Bjerregaard, et al,
pub. by Struers, 1992,revised 1996, ISBN 87-982864-2-0.
- "Metallographic Etching," G. Petzow,
pub. American Society for Metals, 1978, ISBN 0-87170-002-6.
- "Metallographic Polishing by Mechanical Methods, 3rd Ed."
L. E. Samuels, American Society for Metals,ISBN 0-87170-135-9.
Illustrated examples of Polish/Etch and copper color metallography
of importance are available
in our Technical Photo Gallery.