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Posted

Are ther any metallurgists, or metallurgists in training out there?

 

Wouldn't the resonances that occur when an iron mallet hits a steel carpace tend to be transmitted to and embedded in the steel as information? Might not it be possible that this information is recoverable?

 

aguy2

Posted

In theory, (and stretching theory to the limit here for the sake of argument,) there is a possibility that the blow would show up in the grain structure of the steel via work hardening. Getting this information back out would require etching the steel away one layer at a time and comparing the grain boundaries against some known standard.

 

I will leave the practical implementation of the process to you.

Posted

could possibly use neutron scattering to create phonons to build up a picture of teh crystal before and afterwards, and depending of the structure of steal and the deformations the blow had x-ray scattering around the lattice points may work also.

Posted

Etch and electron microscope is the only way I know you will see the subtle changes that would be produced. And like I said this is stretching it. X-rays (actually you would need rather high gamma) doesn't have the resolution for this type of investigation

Posted
could possibly use neutron scattering to create phonons to build up a picture of teh crystal before and afterwards, and depending of the structure of steal and the deformations the blow had x-ray scattering around the lattice points may work also.

 

You realize, of course, that if we could get even one legitimate eighteenth century -CLANG- there could be no end to grants studying the tendencies of resonances to perpetuate. Among other things.

 

agoII aka aguy2

Posted
In theory' date=' (and stretching theory to the limit here for the sake of argument,) there is a possibility that the blow would show up in the grain structure of the steel via work hardening. Getting this information back out would require etching the steel away one layer at a time and comparing the grain boundaries against some known standard.

[/quote']

 

Would a musket ball hole in the carpace be even a better candidate for information retrieval? It might even look like an old fashioned vinyl.

 

aguy2

Posted
Oh yes you would definitely see stress rings after etch from an event like that

 

My background is history (military), soc, and psych, so I would have to take your word on it. What would this 'etching' need in terms of resources?

 

Of course, as a historian, what I would really like would be something like a carrier wave or resonance that sounded like, "Merde!", but even a "Clang" from the past would make the press and open doors.

 

aguy2

Posted

Before I go into detail, be aware that this is a rather destructive process and it will mar the item in question permanently. Second, not much quantitative data can be had from a set of stress riser indications unless you have a set of them to compare from similar events and material.

Posted
Before I go into detail, be aware that this is a rather destructive process and it will mar the item in question permanently. Second, not much quantitative data can be had from a set of stress riser indications unless you have a set of them to compare from similar events and material.

 

One would want start the inquiry with made to order laboratory recreations of the event and its consequences. I wouldn't think of using a real artifact till there where good reason to believe that useful information could be retrived.

 

aguy2

Posted

Enchants:

 

10% by weight ammonium persulfate in water

5% hydrochloric acid in alcohol

5% hydrochloric acid and 1% hydrofluoric acid in water

4% nitric acid in alcohol

 

Process:

 

Solvent clean area under investigation

Polish area to a mirror finish with a series of fine-grit water soluble compounds

Clean with 5% by weight sodium hydroxide solution at 90-100deg C

Rinse with deionized water and dewater/dry by applying methanol

Etch with pre-prepared solution starting with the first on the list

Rinse with deionized water and dewater/dry by applying methanol

Examine area under a metallurgical microscope with polarized light

If results are not satisfactory, repeat process from the top with next etching solution on the list.

Posted

Examine area under a metallurgical microscope with polarized light

 

Thanks for the advice. Do you know where I could find a metallurical microscope and someone with the training to interpert the results?

 

ago2

Posted

Metallurgical microscopes are not uncommon items - as for interpreting the results - that's were you come in. You will have to run controlled tests with the alloys that you are interested in and compare them with results from the items under investigation.

 

The process I gave you by the way, is only for mild steels and cast iron. If you need to do this with any others you need a separate suite of etches.

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