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Metallography

  • 1.  Metallography

    Posted 02-28-2020 08:33

    Is metallography an art or a science?



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    Scott Henry
    Senior Content Engineer
    ASM International
    Materials Park OH
    (440) 338-5401
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  • 2.  RE: Metallography

    Posted 03-01-2020 10:00
    Definitely art. I have come across people who have enough experience to make it seem like a science, but there is definitely an art to getting a sample prepared right, and it never seems to be exactly the same process each time.

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    David Betz
    Sr. Laboratory Engineer
    Hydro Aluminum Metals, USA
    dbetzasm@gmail.com
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  • 3.  RE: Metallography

    Posted 03-02-2020 10:03
    I agree that Metallography is an art. I worked with variety of metals and plastics, started from Powdered metals, Aluminum, Magnesium, Cobalt base and Nickel base alloys with some new materials which had soft and hard phases. All had different ways of preparing the sample. Now I am in steel alloys which relatively set process. Whenever I need good a edge retention and good microstructure resolution, I always hand polish it. I guess that is the way I learned in my Lab class years ago.

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    Sanjay Kulkarni
    Materials Engineer
    MSSC
    Troy, MI
    248-840-1056
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  • 4.  RE: Metallography

    Posted 03-02-2020 12:59
    Yes.

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    Ken Kirby
    Snap-on, Inc.
    Kenosha WI
    (262) 748-3836
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  • 5.  RE: Metallography

    Posted 03-03-2020 13:54
    Metallography was a science up to 70's of last century. There was a flow of papers on metallographic etching. Later the flow of papers dimmed and almost nullified. Thus, with fewer and fewer people having a sound scientific background, metallography has become an art with competence trasmitted by word of mouth in specific laboratories. When the oral transmission stops, then knowledge is lost. Universities do not give a specific preparation anymore. Scientific articles showing metallographies do not indicate etchant any more or very rarely.

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    Donato Firrao FASM
    Professor
    Politecnico di Torino
    Torino
    +393351494032
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  • 6.  RE: Metallography

    Posted 03-08-2020 14:11
    Donato Firrao
    Metallography was a science up to 70's of last century. There was a flow of papers on metallographic etching. Later the flow of papers dimmed and almost nullified. Thus, with fewer and fewer people having a sound scientific background, metallography has become an art with competence trasmitted by word of mouth in specific laboratories. When the oral transmission stops, then knowledge is lost. Universities do not give a specific preparation anymore. Scientific articles showing metallographies do not indicate etchant any more or very rarely.

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    Donato Firrao FASM
    Professor
    Politecnico di Torino
    Torino
    +393351494032

    I'm a graduate of the '70's.  We didn't have papers to read, we were trained at college and had to read 'Kehl' which was even then long out of print!  Generally people learned from others, and that usually degrades knowledge with each generation.  The change to semi-automatic and automatic preparation, with recommended menus and steps and force and times, was a huge step forward.  This allowed training to be much simpler and results to be more reproducible. 
    A resource of others with experience to consult with, is still very valuable to have.  But the vendors are now in a position to provide recipes based on past success.
    As far as papers not showing etchants, this is part of the modern state of technical report writing, and is to be deplored. 
    Personally I prefer micrographs to show the magnification as well as a micron mark, though I understand why the latter is more important. One instructor that I had would give a quiz occasionally, showing an unknown material micrograph and challenging us to identify it, and to state our assumptions why we made that choice.

    So to my answer to the original question, Metallography is a science but results were strongly skill-based, and it was made more scientific by the development of automated equipment and other standardized practices.

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    Paul Tibbals, P.E.
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  • 7.  RE: Metallography

    Posted 03-10-2020 22:14
    A graduate of the University of London in 1963 our practical classes in metallography included specimen preparation,plus long hours under microscope drawing microstructures at different magnifications in circles,identifying phases and making report as course work to be submitted at the end of the year examination.It was the heart and body of the subject called metallurgy.Examples of uses are far and wide.Some examples I have come across include
    1Final oxygen content in copper melt before casting  done by metallography through comparing with Standard. I remember the cutt off point 0.025% as I used to do as practical trainee (under international exchange programme from London University)at Boliden works in Shelleftaham,Sweden
    2.In ERW tube manufacturing, QC is totally dependent on metallopgraphy of weld joint.Standard practice we used to follow in our works in Tube Products ,a subsidiary of TI, UK.
    2,More advanced version,SEM-EDAX(at TI Labs, Hinxton Hall, Cambridge) I used to investigate failure to make crack free ERW tubes from hot rolled  skelp.SEM EDAX studies showed the failure due to Type II MnS stinger inclusion  3,TEM i found extremely useful while working on micro-alloyed HSLA..4.High temperature metallography found useful in studying wear properties at elevated temperature of alloys and ceramics( Nikkon High Temp.Hardness, SEM with high T adopter.Phillips)
    3.latest was High

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    Ram Chattopadhyay
    Mumbai
    91226324762
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  • 8.  RE: Metallography

    Posted 03-03-2020 15:12
    There are aspects of metallography that fall on both sides of that debate. I spent 13 years with a major metallographic product supplier (Allied High Tech Products). I led the research laboratory and technical services there for 6 years, and I've personally worked with thousands of metallographers from around the world.

    I came away with these observations:

    Sample preparation itself is a science. There is a lot of trial and error involved; people with more experience have already made those errors, making it look like an art (or even magic!). However, at Allied, we really did strip sample preparation down to a scientific process with measurable differences between procedures. If two people work on the same sample with the "same" process and get different results, my team at Allied would be able to tell you exactly how the process wasn't the same.

    Microscopy and analysis are science. Again, there is trial and error, but methods are repeatable and processes can be troubleshooted.

    Art, however, is derived from the results of those scientific processes: unique microstructural features, beautiful patterns in results, interesting communication methods, contextual hints, etc. Those are the things that evoke emotions, get people talking, and make metallography memorable.

    Just my two cents 😉

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    Gee Abraham
    STEM Writer/Editor
    www.GeeAbrahamEdits.com
    Gee@GeeAbrahamEdits.com
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  • 9.  RE: Metallography

    Posted 03-04-2020 08:00
    I spent 30 years in the Metallographic Laboratory at B&W.  When I started sample preparation was manual and believe me it was definitely "art". ​  Etching the sample was part science and part art as was photomicrography.  With all of the equipment available today it has become more science and I'm not sure that is all good.

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    [Gene] [Homer] [P.E.]
    [Metallurgical Engineer]
    [Babcock & Wilcox - Retired]
    [Barberton] [OH]
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  • 10.  RE: Metallography

    Posted 03-09-2020 15:23
    It depends on what is your "association" with metallography. Broadly, some of us process micros by which metallography can be studied. Some of us use microstructure examination as a means to understand what the metallurgical history of a component might be, what we might get in terms of understanding a failure which has occurred, or a reaction to mechanical input was different than expected, and so on. Some of us do both. So, we have producers and consumers. I believe that the ability to produce beautiful, interpretable microstructures is priceless, and includes an artistic component. Speaking as one who is really crappy at micro prep, and is a 40 year "consumer" of good micros, I really appreciate the metallographic skills that produced micros with clear structures. These made a lot of science - based conclusions possible.

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    Neil Kilpatrick
    Owner
    GenMet LLC
    Winter Springs FL
    (407) 760-7293
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  • 11.  RE: Metallography

    Posted 03-11-2020 07:04
    In my world, it's both.  I do sample prep for semiconductors (both bare dice and packages) for failure analysis and construction analysis.  I use some standard metallography equipment but the methods for making the sections are highly modified.  I usually make un-encapsulated sections due to the size of the sample.  I don't use any standard metallographic etchants, except for ferric chloride to look at Cu grain structure in lead frames.
    The art comes in preparing the sample for cross-sectioning, such as how to fixture and in what direction.  The science part is the media selection for the actual sectioning, as it's the usual progression of grinding media from rough to fine with a final polish step.

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    Becky Holdford
    Physical Failure Analyst
    Texas Instruments Retired
    Garland TX
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  • 12.  RE: Metallography

    Posted 03-13-2020 08:22
    For me is an incredible amazing science and in the hands of the person who does is an art and it is again amazing!! 
    I receive so often comments from colleagues who develop their careers in other fields saying How amazing!, how much info you take from these studies or why I do not choose your field?
    Now with 13 years of experience, I have no regrets, I am proud that as a chemical engineer has chosen this Metallography to develop my professional path.

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    Silvana Carrizo
    Chemistry Engineer - Metallurgy Analyst - Researcher and Teacher
    National Technological University Mendoza Faculty (UTNFRM)
    Lujan de Cuyo, Mendoza
    54-261-5577229
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