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             Frequently Asked Questions

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 can I learn about EBSD?

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 "A 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 Scientific Group Thermodata Europe (SGTE) also maintains phase diagram data from the SGTE database SSOL and calculated with Thermo-Calc. The web version was then created by M. Schalin in 1997.
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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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How do I prepare and etch cast iron specimens?

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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Where can I get a digital camera for my microscope?

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
Diagnostic Instruments Inc. sells a high resolution digital camera called "SPOT" that was 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 others by doing a "Keyword Search" for "digital camera" at the Microscopy Vendors Database maintained by Henrik Kaker.
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.
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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

Buehler., of Lake Bluff Illinois, also has an ambitious schedule of courses available at several locations around the world. These include:

Fundamentals of Metallographic Techniques Practical Applications of Automated Image Analysis
Petrographic Preparation PWB Preparation
Metallography of Ferrous Metal Heat Treatment Failure Analysis of Electronics

LECO Corporation offers several courses at their St.Joseph, Michigan headquarters including:

Basic Metallographic Techniques
Fundamentals of Weld Metallurgy and Metallography
Metallographic Analysis
Principles of Metallurgy and Interpretation in Ferrous Alloys

For additional information phone (269) 982-2385 and ask for the Metallographic Course Coordinator.


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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:

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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Are there any recommended standard methods or practices for performing metallographic procedures? What organization is responsible for creating these standards?

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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Where can I find lots of materials-related information that is not necessarily related to metallographic techniques.

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. 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. 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.
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 Testing Buyers Guide where you can search for Image Analysis vendors.
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What are the differences between brightfield, darkfield, polarized light, and differential interference contrast? Which illumination mode is best for my particular sample?

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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Is there a central archive with all sorts of tips and tricks for TEM, SEM Computers, Photography, Safety, and Light Microscopy?

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. However, Steve Chapman of ProTrain has a selection of tips and tricks for electron microscopy at http://www.emcourses.com/tips.htm, and Olympus maintains a Microscopy Resource Center at http://www.olympusmicro.com/index.html
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The Ask the Experts Metallography Forum page only contains discussions posted during the last couple of months. Is there some way I can read previous discussions which may be of interest to me?

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?

Questions are screened by a moderator. If the question did not meet the guidelines listed on the page, it was deleted by the moderator. If your message was appropriate, it will be posted to the page within 24 hours.
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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://www.scriptarchive.com/.
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