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Archiving Metallographic samples

  • 1.  Archiving Metallographic samples

    Posted 02-26-2021 08:46
    Good morning ASM team,

    I am looking for the best practices for long term archiving of metallographic samples. This only includes the mounted samples.
    I would appreciate it if you share the procedures that you are following in your lab and I'm wondering if there are any storages designed for this purpose in the market. 

    Thanks everyone in advance!

    ------------------------------
    Neda Mandkarian
    Metallurgist
    McLAren Engineering
    Livonia MI

    ------------------------------


  • 2.  RE: Archiving Metallographic samples

    Posted 02-27-2021 02:31
    For archiving metallographic samples, (broken record) it all depends. We had fine luck storing Ti, Zr, Ni, and  many Fe samples in closed cabinets for years. At worst most only need a quick final repolish and etch. More recently I have left similar samples in LECO desiccator cabinets for years without issue. Other more reactive alloys samples, like Ca, Mg, or Co can have a fairly short storage life. You might be able to store them under Ar, but you should expect to need to repolish them if you need them later. What kind, or what is the base elements, of the samples you are trying to store?

    ------------------------------
    Joseph Tylczak
    Metallurgist
    Albany OR

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  • 3.  RE: Archiving Metallographic samples

    Posted 02-28-2021 11:32
    Agree that preserving mounted samples is not so hard as they can be repolished without damage.  But, fracture surfaces are a very different matter.  Several years ago (mid-1970's) a group of us in SAE performed a round robin to evaluate the use of a wax based, petroleum solvent (Tectyl 506) for use as a preservative coating.  Steel and cast iron fractures were coated and exposed to a high humidity environment for 14 days.  Before and after SEM fractographs demonstrated no damage to the surface.  A quick Google search suggests this material is still available.  (A Coating for the Preservation of Fracture Surfaces; Boardman, Zipp, & Goering; SAE 750967) 

    --
    Bruce Boardman, FASM
    14666 Roos Hill Rd
    Geneseo, IL 61254
    309-944-8700 (home)
    309-716-1766 (cell)





  • 4.  RE: Archiving Metallographic samples

    Posted 03-01-2021 09:23
    Hi Joseph,

    Thank you for sharing your experience with me, my samples are 90% steel and 10% aluminum.

    ------------------------------
    Neda Mandkarian
    Metallurgist
    McLAren Engineering
    Livonia MI
    248-257-2355
    ------------------------------



  • 5.  RE: Archiving Metallographic samples

    Posted 02-27-2021 17:00
    It really all does depend on the material and how much you might need to reuse the samples. After 40+ tears working in archaeometallurgy I have the best part of 10,000 samples, the majority being copper and silver alloys with some gold samples and even fewer iron (I leave iron to others). I retired in 2014 and the sample collection is at home with me, basically filed in sets of small drawers with no desiccants. Being archaeological samples they are likely to be corroded but I only have two samples out of all that number which are actively corroding. With the rest, if I need to reuse them, it only takes a very few minutes to re-polish and re-etch. The most important aspect of the archive is documentation and keeping track of the samples. That is my main concern at the moment when trying to find an appropriate archive for making the samples, with any analytical data, available to others long in to the future.

    Regards,
    Peter Northover

    ------------------------------
    Peter Northover
    Retired
    University of Oxford
    +44 1865 820543
    peter.northover@retired.ox.ac.uk
    ------------------------------



  • 6.  RE: Archiving Metallographic samples

    Posted 02-28-2021 16:07
    Edited by Paul Tibbals 02-28-2021 16:09
    Hi Neda, I agree with the previous response from Joseph Tylczak.  We used cabinets with multiple drawers, with rows/columns identified as needed.  A log book (how quaint, paper! But it's durable and good for evidence -  or an entry in a LIMS) should be kept with your job or other identifier, and the sample ID, maybe a short description.  The cabinet should be indoors in a climate-controlled area, and the cabinet needs to have a dessicant, often kept in an open tray at the bottom.  You may want to get some that have room for more than one size of specimen, for instance for macro samples that are not in a standard mount, depending on your work. At one point we were using either clear mounts or putting a small amount of clear material in the bottom of the mount, and embedding a paper tag with the sample ID, but that was a lot of work, so using an electric or pneumatic engraver to apply the sample ID to the mount was how we mostly did it.  Obviously it's best to do the engraving when the sample surface of interest hasn't yet been prepared, to minimize damage.

    In a quick search I found a few listings under specimen storage cabinet at some of the metallographic / microscopic suppliers, such as this one:
    https://www.metallographic.com/Metallographic-Equipment/Metallography-furniture.html#SPEC-STORE    No endorsement is intended.
    I have used such cabinets under the Buehler and Pelco names, but these were purchased literally decades ago and I don't know what ones are still available.

    ------------------------------
    Paul Tibbals
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  • 7.  RE: Archiving Metallographic samples

    Posted 02-28-2021 22:12
    Hello Neda,

    I have worked with materails from archaeometallurgy and industrial metals, in our laboratory at University, we store them when we finished our studies wrapped in cotton and then sealed with scotch tape. Then we store in plastic boxes numbered with the entry number of the study piece, this is because due to the quality system we must keep them for 4 years.

    I hope it helps you, what we do is simple but it has always given us results and it is also economical.

    ------------------------------
    [Patricia Silvana] [Carrizo]
    [Ms.]
    [Chemical Engineer]
    [Archaeometallurgy Area - UTN FRM]
    [Mendoza] [Argentina]
    [+542615577229]
    ------------------------------



  • 8.  RE: Archiving Metallographic samples

    Posted 03-01-2021 09:14
    Neda,

    This might be "cheating" or not exactly what you're looking for but if your microscope has a camera hooked up to it, you can just take pictures of your micros and store them electronically. You can take a couple different pictures at different magnifications / fields of view and that might be satisfactory, depending on what features you're looking for in the micro.

    Also "cheating" in a way but if you have enough stock in the micro to re-prep it down the road and that wouldn't destroy any particular feature of interest, you can just throw them in a box and re-prep whenever you want. As Bruce mentioned, you couldn't do this for ​a fractograph but if you're looking for generic microstructural features for QC purposes on a forging or something like that, it would be adequate.

    ------------------------------
    Sean Piper
    Product / Process Metallurgist
    Ellwood Texas Forge Houston
    Houston TX
    773-524-8985
    ------------------------------



  • 9.  RE: Archiving Metallographic samples

    Posted 03-01-2021 09:33
    @Sean Piper
    Thank you for sharing this Sean, We need to archive the physical samples for our future design projects. ​I prefer to store them in an organized way since we might come back to them few years later and need to have a good traceability. 
    But this was not cheating, it was actually a good suggestion :).

    ------------------------------
    Neda Mandkarian
    Metallurgist
    McLAren Engineering
    Livonia MI
    248-257-2355
    ------------------------------



  • 10.  RE: Archiving Metallographic samples

    Posted 03-01-2021 09:36

    Thank you Patricia for sharing this, this was a helpful comment.



    ------------------------------
    Neda Mandkarian
    Metallurgist
    McLAren Engineering
    Livonia MI
    248-257-2355
    ------------------------------



  • 11.  RE: Archiving Metallographic samples

    Posted 03-01-2021 20:27
    Thanks Neda,

    Curiously, in our laboratory we have boxes numbered according to the order number of the piece when it enters the laboratory and they are like the image that Peter has attached. We do this as a result of the mid-year internal audits and the annual year-end audits. It has worked for us, and if necessary, it is polished a little like Ken said and ready to continue the studies or resume them.

    Kind Regards,

    ------------------------------
    [Patricia Silvana] [Carrizo]
    [Ms.]
    [Chemical Engineer]
    [Archaeometallurgy Area - UTN FRM]
    [Mendoza] [Argentina]
    [+542615577229]
    ------------------------------



  • 12.  RE: Archiving Metallographic samples

    Posted 03-01-2021 10:41
    Yes, there are storage cabinets for mounts available from companies that sell metallographic equipment.

    Personally, after having them in a smaller cabinet for a year, I put them in large plastic bags. It is probably not ideal, but for my purposes, I would normally repolish the sample if I need to look at it after its been in storage for a long period of time.

    ------------------------------
    Ken Kirby
    Snap-on, Inc.
    Kenosha WI
    (262) 748-3836
    ------------------------------



  • 13.  RE: Archiving Metallographic samples

    Posted 03-01-2021 11:39
      |   view attached
    Hi,

    I attach a picture of the way I keep my samples - in components drawers from the hardware store. The drawers are easy to label and the mounts, numbers engraved on the back, are sorted by project. This is about 15% of the collection. The ledgers contain the documentation for the samples; the collection goes back to the mid-70s and so these records are in manuscript. Sample storage cabinets with nice trays and desiccants can be very good but a) they take up lot of space and b) for this number of samples are prohibitively expensive. Both these are real obstacles for someone working at home. 

    A couple more comments from the archaeometallurgy world on this thread. The world's oldest metallographic samples, those of Henry Clifton Sorby, from the 1860s are preserved at Sheffield University in the UK. Some years ago they were published in Historical Metallurgy.(Edyvean, R.G.J, and Hammond, C., 1997: "The metallurgical work of Henry Clifton Sorby and an annotated catalogue of his extant metallographic samples", Historical Metallurgy, 31(2), 34-85). I115 samples are preserved and many are still useable (it was decided not to reprepare them0. Almost all date to 1863-5, and are of irons and steels, so you can leave even those that long. 

    On fractography, nature is sometimes kind to you. In eastern England in about 1100 BC a bronze Age metal workshop closed down. All the metal on hand was collected up, including the floor sweepings, and put in a very large pot, sealed, and buried in a silted up ditch, and there it remained until hit by a plough in 1959. It would appear that the bulk of the 8000 fragments had been sitting in stagnant air for over 3000 years, and the surface corrosion is about 750nm of tin dioxide. This means that some basic fractography is very possible, so we can tell how these objects were broken up. It is an amazing resource on how metalworking was done at the time..

    In summary then, yes we need to take some care of our samples but not as much as the equipment manufacturers try and tell us.

    Regards,
    Peter


    ------------------------------
    Peter Northover
    Retired
    University of Oxford
    +44 1865 820543
    peter.northover@retired.ox.ac.uk
    ------------------------------



  • 14.  RE: Archiving Metallographic samples

    Posted 03-02-2021 08:29
    Thank you so much, your collection is very neat and organized. And I love the history of oldest samples that you shared, thanks a lot for your time.

    ------------------------------
    Neda Mandkarian
    Metallurgist
    McLAren Engineering
    Livonia MI
    248-257-2355
    ------------------------------



  • 15.  RE: Archiving Metallographic samples

    Posted 03-02-2021 08:30
    Thank you so much for sharing your experience Ken.

    ------------------------------
    Neda Mandkarian
    Metallurgist
    McLAren Engineering
    Livonia MI
    248-257-2355
    ------------------------------



  • 16.  RE: Archiving Metallographic samples

    Posted 03-02-2021 07:20
    Neda,

    We have mount protection caps.
    https://consumables.alliedhightech.com/Mount-Protection-Caps-p/mtcaps.htm

    Put a small about of cotton inside to prevent scratching then put the cap on. Store it in a low humidity environment such as a mount storage cabinet.,
    https://consumables.alliedhightech.com/Mount-Storage-Cabinet-p/mtstrcab.htm

    I hope that helps. 

    Ed Hirsch
    ehirsch@alliedhightech.com




    ------------------------------
    Edward Hirsch
    Allied High Tech Products
    Hampstead NC
    9198469628
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  • 17.  RE: Archiving Metallographic samples

    Posted 03-02-2021 08:20
    Thank you Edward, I love the idea of caps. Do you remember how much you paid for a pack of 50?

    ------------------------------
    Neda Mandkarian
    Metallurgist
    McLAren Engineering
    Livonia MI
    248-257-2355
    ------------------------------



  • 18.  RE: Archiving Metallographic samples

    Posted 03-02-2021 08:24
    I just saw that you are from Alliedhightech, I would appreciate it if you send me a quote for item 198-20005 to  mandkarian.n@gmail.com 
    Thanks again!


    ------------------------------
    Neda Mandkarian
    Metallurgist
    McLAren Engineering
    Livonia MI
    248-257-2355
    ------------------------------