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Materials Science

Ed

Philosopher
E
Joined
Aug 4, 2001
Messages
8,658
I understand that one can obtain the composition of anything through neutron bombardment.

Are there other techniques? Where does one go for such a test? Do you need a cyclotron or something large and expensive or is it possible to do such stuff at home?

I remember seing a sorta portable unit on a tv show.

Who knows about this stuff?
 
There are several other tests I'm aware of for analytical chemistry. FTIR (Fourier Transform Infrared Spectroscopy), XRD (X-ray Diffraction), XRF (X-Ray Flouresence), GCMS (Gas Chromotagraph - Mass Spectroscopy), and other methods. It sort of depends on what one is looking for.

XRF is pretty quick, but there are some atomic numbers it can't detect (below AN 11 if I recall correctly).

XRD is generally an overnight analysis and like FTIR requires the analysist to compare the patterns to a standard pattern from a book and therefore is a bit more subjective.

Anyhow, I work with lots of folks that do this work. If you have a specific question, I'd be glad to get you an answer from experts.
 
I am looking at ways of characterizing weapons from the historical period (say 1000-1700 AD) using such a technique. The material would be steel/iron and the technique needs to minimally invasive.
 
Ed said:
I am looking at ways of characterizing weapons from the historical period (say 1000-1700 AD) using such a technique. The material would be steel/iron and the technique needs to minimally invasive.
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What info exactly are you looking for? Are you looking for basic composition information (is there anything besides iron in it), or fine-tuned info (how MUCH carbon is in the steel)? And how mininally invasive does it need to be? Do you mean you can only take small bits of the weapon for measurement, or do you need the whole weapon intact?
 
Hummmm. Sounds like you couldn't take a sample of the metal then without messing up the weapon. I assume we are talking swords, axes, and the like?

I'll be visiting our analytical chemistry folks on the 3rd or 4th of September. I'll pose your question to them.

Maybe it could be done with a small sample of some of the swarf from grinding the steel/iron. I'll ask, as your question has really raised my curiosity about this.

Bump this thread on the morning of the 3rd of Sept. to remind me.

Edited to say that it sounds like a wet chemistry method would have to be employed if you want specific percentages of each element. XRD and IR tend to be yes/no or major/minor/trace type of results........more quick and dirty (and less accurate re. percentages).
 
I think scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy are commonly used in metallurgical analysis to examine the morphology of a sample and its elemental composition.

They do, however, involve bombarding a small sample in a vacuum with high energy electrons, so it would involve removing a small bit of the sword.

I imagine a university with a metallurgical department would be willing to do the analysis for you. Dunno how expensive it would be, though.
 
JamesM said:
I think scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy are commonly used in metallurgical analysis to examine the morphology of a sample and its elemental composition.

They do, however, involve bombarding a small sample in a vacuum with high energy electrons, so it would involve removing a small bit of the sword.

I imagine a university with a metallurgical department would be willing to do the analysis for you. Dunno how expensive it would be, though.
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We have SEM's, TEM's, Scanning/Tunneling microscopes, etc. where I work also.

If Ed's material is small enough to send through the mail, I might be able to get it analyzed gratis.
 
If this can be done, why haven't other cymbal manufacturers been able to reproduce Zildjian's secret alloy? Or is there more to an alloy than simple composition?
 
WildCat said:
If this can be done, why haven't other cymbal manufacturers been able to reproduce Zildjian's secret alloy? Or is there more to an alloy than simple composition?
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Link?
 
WildCat said:
If this can be done, why haven't other cymbal manufacturers been able to reproduce Zildjian's secret alloy? Or is there more to an alloy than simple composition?
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I can't speak specifically about cymbals, but generally speaking there are a lot of other factors that affect the material properties of an alloy, like grain size, residual stress, etc. that all result from the way the alloy is processed. Knowing the composition alone is not necessarily enough to duplicate the desired properties.

Also, beware the possibility that nobody else actually cares about the "secret" to Zildjian's alloy, that it's just a marketing gimmick - if nobody cares, then there's no reason to find the secret. Again, I don't know anything about cymbals so I can't say whether or not there actually is anything special about that alloy, but it's something to at least consider.
 
Diamond said:


Link?
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Here ya go.

Ziggurat said:
Also, beware the possibility that nobody else actually cares about the "secret" to Zildjian's alloy, that it's just a marketing gimmick - if nobody cares, then there's no reason to find the secret. Again, I don't know anything about cymbals so I can't say whether or not there actually is anything special about that alloy, but it's something to at least consider.
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Maybe so, but Zildjian dominates the market. I'd bet 70-80% of professional percussionists use them, and they seem to command the highest prices. Been around for hundreds of years also.

Anyway, Zigurat's mention of grain size, etc. basically answered my question, that there is more to it than just composition.
 
WildCat said:

Here ya go.


Maybe so, but Zildjian dominates the market. I'd bet 70-80% of professional percussionists use them, and they seem to command the highest prices. Been around for hundreds of years also.

Anyway, Zigurat's mention of grain size, etc. basically answered my question, that there is more to it than just composition.
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Yes. It is called "marketing".
 
Ed,

I hope to talk to someone tomorrow about your question.

Just to be clear......you are interested in precise percentages of each material in the steel, iron, or other alloy used in these weapons, correct?

Nothing more? Nothing less?
 
Mr. Skinny said:
Ed,

I hope to talk to someone tomorrow about your question.

Just to be clear......you are interested in precise percentages of each material in the steel, iron, or other alloy used in these weapons, correct?

Nothing more? Nothing less?
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Yup-a-diddley-doo

If there are psychic images impressed on the matrix of the material that would show me actual images of the users of these things over time, I would have a passing interest:D
 
Ed,

I spoke with one of my analytical chemist co-workers today.

He knew of no non-destructive methods that could be employed (short of hiring someone with a nuclear reactor).

He suggests ICP (Inductively Coupled Plasma) and Inert Gas Fusion tests to gain the data you wanted. He is capable of performing both tests.

I didn't get a chance to discuss sample size with him, nor did I ask him if he'd be willing to run them for you, as he was in the middle of a meeting with someone from the NTSB.

I'll get back with him tomorrow to discuss details.

How many weapons do you want analyzed? I'd like to give him an idea of how much lab time he'd be looking at "donating" in order to get you the results you want.
 
A couple, anyway. The issue is the detructive/non-destructive thing. How big a sample are they talking about?
 
Ed said:
A couple, anyway. The issue is the detructive/non-destructive thing. How big a sample are they talking about?
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I'm not sure how big the samples need to be. I've given him some pretty miniscule samples in the past with good results.

I think he would need two small samples from each object. Eliminating contamination in the sample would be critical, I'd think. Perhaps a few filings taken with a diamond stone, and placed in a container that would in no way contaminate the sample.

I think four samples to test two objects, with minimal harm to the object may be possible.

I'll handle this via PM from this point, Ed. I'm looking forward to this working out.
 
Skinny..

This is the technique that I was thinking of

http://www.icconsultants.co.uk/asg/asg2.html

Neutron activation.

The good news: you can measure down to trace amounts for 60 elements. You irradiate the entire sample ... no peskey cutting off of bits.

The bad news: you need a nuclear reactor ... This might or might not be a problem.

Ask your guys
 
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