Frequently Asked Questions
Frequently Asked
Most of the visitors to Metallography.com
are practicing metallographers and technicians or are learning the
techniques as part of an advanced education in some materials science field.
Metallography is variously described as an art or a science or both. The
Metals Handbook Desk Edition defines metallography as " The science
dealing with the constitution and structure of metals and alloys as revealed
by the unaided eye or by such tools as low-powered magnification, optical
microscopy, electron microscopy and diffraction or x-ray techniques."
These are answers to questions frequently discussed at
The Metallography Forum . They
are posted here to help direct you to other useful resources. Click on a
question to see the answer.
Where on the Internet can I find phase diagrams?
Try The
Phase Diagram Web a free service of The Georgia Tech Joint Student
Chapter of ASM/TMS.
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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 Ltd.. 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.
Another excellent review/tutorial can be found at Sound Vision
Incorporated's,
"How Digital Cameras Work" which deals with the technical issues
and recommendations of camera types based on application needs.
The following list is not meant to recommend any particular camera.
The Scientific Imaging Systems group of the Eastman Kodak Company offers
a Microscopy Documentation System based on the Kodak Digital Science
DC120 digital zoom camera. For more information on the Kodak camera
send email to Robin Montmayeur Microscopy Marketing Specialist (rlmont@kodak.com)
or contact Kodak's Technical Support Group at sis-support@kodak.com
or call 877-SIS-HELP.
Diagnostic Instruments Inc. sells
a high resolution digital camera called "SPOT" that was specifically designed
for use on microscopes.
Polaroid
has a digital camera called the "DMC" or Digital Microscope Camera.
Sci-Eye Inc offers a miniature
color camera for microscope use called the MMC-2. It has lower resolution
than the others mentioned above (320X240).
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.
The list of
vendors maintained by ASM International might also include
those offering digital camera equipment.
You'll find many others 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. 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 |
Several of these courses are available via correspondence, on video tape, and even on the internet. The entire ASM course schedule is available online. For more information call 800-336-5152 extension 5616 or send email to mem-serv@asminternational.org. ASM also has local chapters scattered around the country which occasionally sponsor courses locally.
Buehler Ltd., of Lake Bluff Illinois, also has an ambitious course schedule which includes:
| Basic Metallography | Microelectronic Devices |
| Metallography of Fasteners | Materials Characterization of Ferrous Alloys |
| Advanced Metallographic Techniques | PC Boards |
| Failure Analysis of Microelectronic Materials | Petrographic Preparation |
Buehler's complete course schedule is also available online. For more information call Sandy Lund at 847-295-4679. Fax 847-295-7929.
Leco Corporation offers several courses at their St.Joseph, Michigan headquarters including:
| Principles of Metallurgy and Interpretation of Microstructures in Ferrous Alloys |
| Metallographic Techniques |
|---|
For additional information phone 616-983-5531 or fax 616-983-3850 or email Chris Warren (chris_warren@leco.com).
If you're looking for in-house training in heat treating, metallurgy,
metallography, or any of a variety of other topics, contact
AMI Training Services
at 13765, Clover Lake Drive, Chardon, OH 44024; Phone: 440-564-9128,
800-616-0385, Fax: 440-564-7835. For additional information email
Marc Starrett at
mstarrett@cyberdrive.net.
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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:
Buehler Ltd. maintains a good list of recommended books at their website. (or here if your browser doesn't support frames) It includes both "in print" and "out of print" volumes.
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 content 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 the 10,000 volume ASM
Library offers 24-48 hour
delivery
service for copies of: conference papers, journal articles, phase
diagrams, and alloy data sheets. You can also arrange a literature search
through ASM's library and ASM maintains several Webboard Discussion
Forums at their website where you may post questions.
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. One in particular,
"Understanding the Internet: A Guide for Materials Scientists and
Engineers" by Dr. Kenneth J. Meltsner, lists many of the materials
science related newsgroups (discussion groups) available online. You might
also find some help through one of the sites listed on the TMS
"Links to Links" page.
A good source for technical standards on a wide variety of materials
is the American Society for Testing and Materials.
ASTM "has developed and published 10,000
technical
standards, which are used by industries worldwide...Technical
publications, training courses, and Statistical Quality Assurance Programs
are other ASTM products; ASTM services include The ASTM
Institute for Standards Research." You can search their files several
ways and read summaries of the standards online or have complete standards
faxed to you within 15 minutes.
The Principal Metals, Inc.
website offers free access to their "Specifications Cross Reference",
"Material Property Data", and "Prime Metals Weight Calculator". They
cross reference over 6000 AMS, ASTM, ASME, MIL, QQ, UNS and
proprietary DMS, GE (B50) and PWA specifications. There is
complete property data including chemistry, mechanicals, welding, heat treating,
forming, fabricating and application data on more than 5000 ferrous and
non-ferrous alloys. The weight calculator automatically calculates the weight
of rounds, flats, hexagons, sheets, plates, tube, discs and rings in standard
or metric sizes in any metal.
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. You'll also find over 4,000 links to steelmaking and
steel-related technologies at
"Steelynx"
a site maintained by Cathy Stewart (no relation). For technical inquiries
or other steel-related conversation subscribe to
"SteelTalk",
the listserver administered by Ted Kuster a contributing editor for
Iron Age/New Steel magazine.
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.
Metallography.com offers two methods to help you find other information
on the World Wide Web. There is a list of
links to websites for all sorts of materials
organizations and universities at http://www.metallography.com/links.htm.
Or for freestyle searching the entire Internet try the
search page at
http://www.metallography.com/search.htm. You can search by keywords using:
AltaVista, Excite, Infoseek, Lycos, and Yahoo. There are also links to WebCrawler
and HotBot (preset to search for "metallography"), as well as links to 8
other search engines.
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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 several years
ago. 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 list of links to Image Analysis vendors at
http://www.asm-intl.org/testing/directry/30.htm.
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Buehler Ltd. published a great explanation of the various illumination
techniques in a Tech-Notes article written by their director
of research and technology, George Vander Voort. That article is reproduced
here
complete with 15 accompanying micrographs.
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Take a look at the
"Tips and Tricks" archive for TEM, SEM Computers, Photography, Safety,
and Light Microscopy gleaned from the Microscopy and Confocal listservers
and independent contributions. The archive is maintained by Scott D. Whittaker
at the University of Florida, Gainesville.
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Postings are periodically removed and archived so the page will not take
too long to load in your browser. You are welcome to
search the
archives to read any previous discussions related to your topic.
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May I use HTML tags in my message at the Ask the Experts Forum?
No. You may not use HTML tags in your posting. If you try, the script will
just throw out everything between <>'s.
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I typed a message to the Ask the Experts page. Why don't I see it posted on the page?
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Where can I get the scripts that make the Metallography Forum work?
The original cgi scripts (which have been modified for use here) are written
in Perl and created by Matt Wright. They are free to anyone who wishes to
use them. You can get them as well as other scripts at:
http://worldwidemart.com/scripts/.
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