Magnetic weapons

Rivkin · 2nd March 2005, 02:29 AM

Quote:

Originally Posted by Ann Feuerbach

This is all such great stuff.

It will take me awhile to absorb it all and figure out what it all means! I got someone lined up with homemade ingots any suggestions of how to test them? RIVKIN could you suggest any suitable methods?

The problems I see is that:
1. The magnetization depends on two unknown factors - how non-uniform the steel is and what kind of fields the sample was exposed to. Lighting, wielding machines and subways all produce significant fields, capable of magnetizing pieces of iron.

So at least two different experiments should be condacted, unless you are interested in non-uniformities alone. Then the reasonable thing is to ask a steel metallurgist, but I think they actually measure permeability - they take not very large field, apply it to the sample and see what kind of magnetization is produced - it's supposed to be uniform if for example you apply the field along the easy axis (parallel to the sword?), but only if the sample itself is uniform.

Another way is to use X_Ray scattering or conductance or chemical tests - I think all these techniques are been used in the steel industry.

another interesting thing would be to try to achieve the true ground state in the sample by heating it up and cooling it down in the absence of external fields, with probably some random ac fields being applied to the body.

Concerning shape-dependent demag factors, there are programs like rkmag and oomf that allow one to simulate the magnetizations, so you should get the approximate picture of what kind of state you should have.

2. To Mare Rosu:

Thanx for the pictures,
The thing I would consider to be interesting is a conductance test. I don't think it can fire up with a simple resistometer, but it can be that if you place probes at about 5mm from each other on the dagger and move them alongside the dagger's surface that you will be able to see a significant change in the resistance along some set of points, which is possibly can be connected to the changes in the metall itself.

The problem is that not all steels are ferromagnetic, but they are all conductors, so unlike magnetism, you should not see a lot of difference.

P.S. I'm not a steel guy and not an experimentalist, so I really should not give any advices.

Sincerely yours,

K.Rivkin

Jens Nordlunde · 2nd March 2005, 12:25 PM

I always thought ingots were like the round one you show Gene, but after having read Ann’s article in Minerva Magazine No. 13, issue 4, 2002, I was wiser, ingots can be found in many shapes and sizes, the ones made in Merv weighted according to Ann’s article about 2 kg.
Gene how many different ingots do you have, and do they have the same weight?
Is there any writing or marking on them? I remember to have seen a picture of a round ingot with some writing on it.

Ann, do you know if the shape of the ingots was a kind of ‘trademark’ for a region?
Would the kind of clay used, ‘porcelain’ clay vs. other types of clay, have any influence on the ingot?
Maybe we should start another thread on ingots.
Somewhere I saw, that in one of al-Biruni’s (973-1048) books, I think it must be in Kitab al-Hind that he describes iron/iron production(?) in India. Do you know if it is in this book?

Jens

Mare Rosu · 2nd March 2005, 01:04 PM

JENS
This is the link to the wootz bar I had and made it into a Bowie by Al Pendray and also tested by Verhoeven. The end with the inscription is still with Pendray, at least it was the last time I saw him.
http://www.vikingsword.com/ubb/Forum1/HTML/002326.html
Gene

Jens Nordlunde · 2nd March 2005, 01:34 PM

Gene, the ingot you show on the link seems to be round and flat. The one I saw a picture of was shaped like the round one you show on a picture on this topic, but larger - I think. The writing was on top of it, and looked, as I recall it, like the writing on the one you show on the link.

Jens

Ann Feuerbach · 2nd March 2005, 06:39 PM

Thanks Gene for the generous offer!

I will take you up on it as soon as I have time to spend doing research. Right now they would just be used as paper weights, until I finish lecturing this term. I will be looking for ingots and blades to include in the book. Where did you get the ingots from?

Jens Nordlunde · 7th March 2005, 02:49 PM

A small knife I have, in a scabbard together with a katar, is very magnetic, but the katar is not.
The picture to the left shows the tip of the blade, and the one to the right the compass at the base of the blade. The small knife is made in the first quarter of 1600, the katar is newer.

Rivkin · 7th March 2005, 04:02 PM

When magnetic moments are positioned alongside a line (good approximation for thin swords), there are basically two stable configurations - all magnetic moments are oriented along the line, parallel to each other, or they are all perpendicular to the line, and anti-parallel to each other, i.e. +-+-.

What you have most likely shows that you physically have different steels (most likely phases or chemistry) at the tip and for the rest of the blade, so you've these two macrodomains anti-parallel to each other.

2nd March 2005, 01:04 PM	#3
Mare Rosu Deceased Join Date: Dec 2004 Location: USA, DEEP SOUTH, GEORGIA, Y'all hear? Posts: 121	Words? on Wootz JENS This is the link to the wootz bar I had and made it into a Bowie by Al Pendray and also tested by Verhoeven. The end with the inscription is still with Pendray, at least it was the last time I saw him. http://www.vikingsword.com/ubb/Forum1/HTML/002326.html Gene

7th March 2005, 02:49 PM	#6
Jens Nordlunde Member Join Date: Dec 2004 Location: Europe Posts: 2,718	A small knife I have, in a scabbard together with a katar, is very magnetic, but the katar is not. The picture to the left shows the tip of the blade, and the one to the right the compass at the base of the blade. The small knife is made in the first quarter of 1600, the katar is newer. Attached Images

2nd March 2005, 12:25 PM	#2
Jens Nordlunde Member Join Date: Dec 2004 Location: Europe Posts: 2,718	I always thought ingots were like the round one you show Gene, but after having read Ann’s article in Minerva Magazine No. 13, issue 4, 2002, I was wiser, ingots can be found in many shapes and sizes, the ones made in Merv weighted according to Ann’s article about 2 kg. Gene how many different ingots do you have, and do they have the same weight? Is there any writing or marking on them? I remember to have seen a picture of a round ingot with some writing on it. Ann, do you know if the shape of the ingots was a kind of ‘trademark’ for a region? Would the kind of clay used, ‘porcelain’ clay vs. other types of clay, have any influence on the ingot? Maybe we should start another thread on ingots. Somewhere I saw, that in one of al-Biruni’s (973-1048) books, I think it must be in Kitab al-Hind that he describes iron/iron production(?) in India. Do you know if it is in this book? Jens

2nd March 2005, 01:34 PM	#4
Jens Nordlunde Member Join Date: Dec 2004 Location: Europe Posts: 2,718	Gene, the ingot you show on the link seems to be round and flat. The one I saw a picture of was shaped like the round one you show on a picture on this topic, but larger - I think. The writing was on top of it, and looked, as I recall it, like the writing on the one you show on the link. Jens

2nd March 2005, 06:39 PM	#5
Ann Feuerbach Member Join Date: Feb 2005 Posts: 133	Thanks Gene for the generous offer! I will take you up on it as soon as I have time to spend doing research. Right now they would just be used as paper weights, until I finish lecturing this term. I will be looking for ingots and blades to include in the book. Where did you get the ingots from?

7th March 2005, 04:02 PM	#7
Rivkin Member Join Date: Dec 2004 Posts: 655	When magnetic moments are positioned alongside a line (good approximation for thin swords), there are basically two stable configurations - all magnetic moments are oriented along the line, parallel to each other, or they are all perpendicular to the line, and anti-parallel to each other, i.e. +-+-. What you have most likely shows that you physically have different steels (most likely phases or chemistry) at the tip and for the rest of the blade, so you've these two macrodomains anti-parallel to each other.