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  • 1.  MIC or Al and/or Mg casting

    Posted 01-19-2021 10:22
    I am passing these questions around for another person.

    Does microbiological induced corrosion have the ability
    to attack an aluminum casting? Or magnesium casting?

    Do you have any images of this type of corrosion? 
    Or a good link that can provide me with some info? .

    regards,
    Jim

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    Jim Quinn
    Materials Sci & Chem Eng
    Stony Brook University
    Stony Brook NY
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  • 2.  RE: MIC or Al and/or Mg casting

    Posted 01-20-2021 23:52
    There are references easily found with Google that discuss MIC of aluminum, and of magnesium.  Just add the search term MIC to whichever alloy system.  Whether or not the material is in cast form probably does not affect susceptibility, other than the differences in compositions between wrought and cast grades.

    As is often the case with MIC it is more likely in situations where materials can form a film or deposit on the surface of the alloy, and the absence / exclusion of oxygen could also contribute.  This would allow an environment to form or collect that would be conducive to breakdown of the protective oxide film.  I don't have any personal experience with MIC with either of those systems, though I saw it commonly in steel gas pipelines and also in seawater stainless steel exposure.

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    Paul Tibbals, PE
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  • 3.  RE: MIC or Al and/or Mg casting

    Posted 01-21-2021 10:20
    Paul is right, the only thing I will add is that residual stresses can play a significant role in corrosion, especially in passivated metals like aluminum.  For this reason, I would expect cast systems to be less susceptible than wrought to MIC, particularly crack environmentally assisted cracking.

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    David Sapiro
    Engineer
    King George VA
    dosapiro@gmail.com
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