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Frequently Asked Questions |
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Frequently Asked Questions |
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If you don't find what you're looking for through the links and information on this page, or those on the home page, please visit the Ask The Experts Archive search page to find detailed preparation tips for your specific material.
Take a look at the 31 page article,
"EBSD
Explained", by the folks at Oxford Instruments.
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How can I prepare and etch specialty alloys or those which are highly resistant to corrosion?
Please read "Ultimate
Guide to Etching Specialty Alloys for Microstructural Evaluation" by
the folks at CarTech.
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Where can I get Volgel's Sparbeize?
The ground material is made by:
Dr. Hoeck
Prinz-Regent-Str. 48
44795 Bochum
Duesseldorf
It is supplied in 5 kg cans to the Schulz chemical supply company in Duesseldorf
who is making the final product in 250 ml cans.
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Where on the Internet can I find phase diagrams?
ASM International has an online database of Alloy Phase Diagrams available with a subscription access or you can download a single diagram for a very small charge.
The Center for Research in Computational Thermochemistry at the University of Montreal has an online list of 1176 phase diagrams from the
The Scientific Group Thermodata Europe (SGTE).
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How do I prepare and etch aluminum alloys.
One of the panel members received the following information from a researcher in the Czech Republic who works for the Research Institute for Metals and presented a paper about Al 8006 at the 1999 IMS convention:
"We really use Barker's reagent (4 to 5 ml fluoroboric acid in 200ml water), electrolytic anodizing at 20 to 22V during 90 to 180s and then we examine the samples under crossed polarizer and analyzer with sensitive tint."
She also sent along the following preparation procedures for other aluminum alloys:
"We use the most often cold mounting in acrylic compounds, wet grinding on
SiC papers - the usual set is P220, P500, P800, P1200, then coarse polishing
on diamond suspensions - 7, 3 and 1 microns and final polishing on silica
suspension (Buehler MASTERMET 2).
The etchants we use more frequently for macroetching are:
- Tucker's reagent: HCl - 45 ml, HF - 15ml, HNO3 - 15 ml, H2O - 25 ml
- 10 to 20% aqueous solution of NaOH followed by rinsing in 50% aqueous solution
of HNO3
- diluted Tucker: 300 ml HCl, 300 ml HNO3, 5 ml HF, 300 ml H2O
Microetching reagents:
- 0.5% aqueous solution of HF
- 30% aqueous solution of HNO3
- Dix-Keller reagent: 1 ml HF, 1.5 ml HCl, 2.5ml HNO3, 95 ml H2O"
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Janina Radzikowska, Senior Metallographer, The Foundary Research
Institute (Instytut Odlewnictwa) Kraków, Poland wrote an excellent
article entitled "Preparation of
Cast Iron Foundry Alloys." It was originally published by Buehler
in Tech-Notes, Volume 2, Issue 2 and is reproduced here with the
kind permission of the Editor, Mr. George Vander Voort, Director, Research
and Technology, Buehler.. There are 22 accompanying photomicrographs
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If you're new to digital photography, start by visiting
"Curtin's Short Courses
in Digital Photography" for an exhaustive review of the subject.
There's also a comprehensive article on "How Digital Cameras Work" by Karim
Nice, Tracy V. Wilson and Gerald Gurevich at
http://electronics.howstuffworks.com/cameras-photography/digital/digital-camera2.htm
Any full service metallography equipment vendor should be able to supply digital cameras for your microscope, or at least refer you to a company that can.
Spot Imaging sells high resolution digital cameras specifically designed
for use on microscopes.
MIS, Inc. offers the
PAXcam digital microscope camera.
You can see sample photomicrographs taken with the PAXcam at
www.paxcam.com/metallography-images/.
You'll find other vendors of digital cameras by doing a "Keyword Search" for "digital camera" at the
Microscopy Vendors
Database maintained by Henrik Kaker.
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Where can I take a basic metallography course?
There are several places to find basic metallography courses other than at colleges. ASM International offers the largest variety of basic, introductory, and advanced courses at their headquarters outside Cleveland, Ohio (and other locations). A partial list includes:
| Metallography of Plasma Spray Coated Materials | Intro to Metallurgical Laboratory Processes | Microscopy for Metallurgy and Materials Science |
| Advanced Metallographic Techniques | Metallographic Techniques for Advanced Materials | Metallography of Micro-electronic Materials |
| Modern Methods for Ceramography | Field Metallography | Metallographic Applications of Image Analysis Technology |
| Metallography of Fasteners | Metallographic Interpretation | Principles of Failure Analysis |
| Fractography | Mechanical Testing of Metals | Welding Metallurgy |
| Titanium and it's Alloys | Elements of Metallurgy | Heat Treating Quality and Inspection |
Buehler., of Lake Bluff Illinois, offers a 3 day course in fundamentals of metallographic techniques at several locations around the world.
LECO Corporation offers classes at their St.Joseph, Michigan headquarters including:
| Basic Metallographic Techniques |
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| Principles of Metallurgy and Interpretation in Ferrous Alloys |
For additional information phone (269) 982-2385 and ask for the Metallographic Course Coordinator.
Are there any books about metallography?
There are dozens of books relating to metallography. George L. Kehl's book The Principles of Metallographic Laboratory Practice, McGraw-Hill, 1949 was once the metallographer's bible. It still makes interesting reading, if just to gain a better appreciation of our modern methods which we sometimes find so tedious and take for granted. A couple of more modern comprehensive and convenient references are:
There are many others relating to specific materials. Try searching the stacks
at the
ASM bookstore,
Amazon.com,
or
Barnes
and Noble.
Remember, members of ASM International or the International
Metallographic Society are frequently notified of, and receive substantial
discounts on, new publications in the materials field.
Technicians and metallographers should also have a copy of the Annual
Book of ASTM Standards Section 3, Metals Test Methods and Analytical Procedures,
Volume 3.01, Mechanical Testing; Elevated and Low-Temperature Tests;
Metallography. There are 1152 pages comprising 114 standards. According
to ASTM:
"This volume features 20 metallography tests and practices that define standard
optical, electron, and x-ray procedures for determining the constituents
and structure of metals and alloys. Examples: E 384 Test Method for
Microhardness of Materials and E 45 Test Method for Determining the
Inclusion Content of Steel.
Several standard practices cover procedures for determining the effect of
temperature on metals.
55 tests and practices detail the standard procedures needed to perform
mechanical testing, including: machine calibration, bend and flexure testing,
compression, ductility and formability, elastic properties, impact, linear
thermal expansion, shear and torsion, residual stress, and tension testing.
Includes: E 238 Test Method for Pin Type Bearing Test of Metallic Materials
and E 10 Test Methods for Brinell Hardness of Metallic
Materials.
About 10 standards define terms related to fatigue testing and loading, and
explain procedures involved in fatigue testing, such as cycle counting and
statistical analysis. Example: E 606 Practice for Constant-Amplitude Low
Cycle Fatigue Testing.
Nearly 15 tests and practices list the steps required to perform fracture
testing. Includes: E 561 Practice for R-Curve Determination."
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Yes, there are recommended standard practices for metallographic procedures.
The American Society for Testing and Materials (ASTM) Committee E-4 on
Metallography, established in 1916, is responsible for many of them.
To learn more about ASTM Committee E-4, please read the excellent
history from the May '91 issue
of ASTM Standardization News. Here are a few of E-4's
standards:
Metallographers might be particularly interested in the Annual Book of
ASTM Standards Section 3, Metals Test Methods and Analytical Procedures,
Volume 3.01, Mechanical Testing; Elevated and Low-Temperature Tests;
Metallography. There are 1152 pages comprising 114 standards. According
to ASTM:
"This volume features 20 metallography tests and practices that define
standard optical, electron, and x-ray procedures for determining the constituents
and structure of metals and alloys. Examples: E 384 Test Method for
Microhardness of Materials and E 45 Test Method for Determining the
Inclusion Content of Steel.
Several standard practices cover procedures for determining the effect
of temperature on metals.
55 tests and practices detail the standard procedures needed to perform
mechanical testing, including: machine calibration, bend and flexure testing,
compression, ductility and formability, elastic properties, impact, linear
thermal expansion, shear and torsion, residual stress, and tension testing.
Includes: E 238 Test Method for Pin Type Bearing Test of Metallic Materials
and E 10 Test Methods for Brinell Hardness of Metallic Materials.
About 10 standards define terms related to fatigue testing and loading,
and explain procedures involved in fatigue testing, such as cycle counting
and statistical analysis. Example: E 606 Practice for Constant-Amplitude
Low Cycle Fatigue Testing.
Nearly 15 tests and practices list the steps required to perform fracture
testing. Includes: E 561 Practice for R-Curve Determination."
Summaries of all ASTM standards are available at the
ASTM website. You may also phurchase
complete standards from their site.
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Most of the reference materials you'll need are not available in their entirety
online. Many can be ordered online, but if you're in a hurry use online resources
to track down the books, journals, or articles which can then be studied
in greater detail at your local library.
ASM
International is the largest distributor of materials information (not
just metals information) in the world. Their website is a great place to
begin a search. The
ASM
Bookstore is searchable by keyword and contains descriptions and tables
of contents for most of the books ASM publishes. Once you find an appropriate
reference, jot down it's title, author, and ISBN number to help you locate
it in your local library. Or you can subscibe to the
ASM Online
Databases to search for copies of: conference papers, journal articles,
phase diagrams, and alloy data sheets.
METALogic N.V., a spin-off company of
the Department of Metallurgy and Materials Engineering (MTM) of the
Katholieke Universteit Leuren in Belgium, maintains an online materials
information system. It's purpose is to provide concise information on materials
and materials selection criteria for corrosive applications, but the site
contains plenty of other data on a variety of materials from non-metallics
to Zinc.
The Minerals, Metals, and Materials Society
(TMS) maintains a website where you can search the subject index and
tables of contents for their journal
"JOM".
About 40
selected
articles are available in their entirety online. The
TMS Knowledge Resource Center
is a searcheable database of books and publications (some free, others are
not) about all things material.
A good source for technical standards on a wide variety of materials is the
American Society for Testing and Materials
(ASTM). They have developed and published 10,000
technical
standards which are used by industries worldwide. Other ASTM products
include technical publications, training courses, and Statistical Quality
Assurance Programs. You can search their files several ways and read summaries
of the standards online or download complete standards as PDFs (for a fee).
If you're looking for a material to fit your property requirements, Automation
Creations, Inc. has created MatWeb,
a free online materials information resource. MatWeb's database
currently includes comprehensive coverage of thermoplastic and thermoset
polymers, aluminum, magnesium, steel, titanium and zinc alloys, plus a solid
and growing list of ceramics and other metals.
If you're seeking general information about individual elements, you'll find
a wealth of data on the
Periodic Table
maintained by Los Alamos National Laboratory.
For those interested in copper alloys, the
Copper Development Association
maintains a great site full of
copper
alloy micrographs and other pertinent information.
Looking for information about steel? Check with the
Steel Manufacturers Association or
the International Iron and Steel
Institute.
Interested in the preparation of cement/mortar samples? Contact the
International Cement Microscopy
Association via http://www.cemmicro.org/ .
Have a question about heat treating procedures, furnaces and facilities,
or want to participate in general heat treating discussion? Visit
HeatTreatingOnline.com.
Their discussion boards are monitored by a panel of industry experts.
If you're looking for additional information, there is a list of
links to websites for all sorts of materials
organizations and universities at http://www.metallography.com/links.htm.
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How were the methods for determining grain size developed?
To find out more about the evolution of grain size measurement, please read
the history of ASTM E112 at
http://www.metallography.com/grain.htm. The article originally appeared in
ASTM Standardization News.
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How do tint etches work and can you suggest any for copper alloys and steel?
An excellent article called
"Tint Etching"
was printed in Metal Progress magazine. It is reproduced at http://www.metallography.com/etching/tint.htm complete
with 11 micrographs and 21 selected tint etches.
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Where can I find information about automated image analysis software?
You could start by reading these two articles
"Image Analysis for Materials Science" ,
reproduced from an article that originally appeared in Metal
Progress magazine and
"Choosing an Imaging
System" reproduced from Advanced Materials and Processes
magazine. There are several other articles on quantitative microscopy
and image analysis at Clemex
Technology's site. Then visit ASM International's website
where they maintain a Testing Buyers
Guide where you can search for Image Analysis vendors.
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Check out the great explanation of the various
illumination
techniques published by Buehler in a Tech-Notes article written by their director
of research and technology, George Vander Voort. It includes 15 accompanying micrographs.
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I don't think there is a central archive anymore since the one at the University
of Florida (http://www.biotech.ufl.edu/EM/tips/index.html) shut down and Steve Chapman of ProTrain retired, but Olympus maintains a Microscopy Resource Center at
http://www.olympusmicro.com/index.html
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