Forging / smithing

[Jan]

Mr. Mark, as you surely know, some ten years ago German researches revealed carbon nanotubes and cementite nanowires in the blades of Damascus steel. If I understand it correctly the nanowires were encapsulated and protected by the carbon nanotubes. This may contribute to understand better the remarkable properties of the Damascus steel.

http://news.nationalgeographic.com/news/...words.html

       

P.S.: Please distinguish between carbon nanotubes and carbon fibres. Carbon nanotubes have a diameter circa 0.001 micron while the carbon fibres are about 5 to 10 microns in diameter. The walls of carbon nanotubes are made of one atom thick sheets of carbon. The way how the carbon sheet is rolled decides whether it will behave like a metal or a semiconductor.

[Mark Reich]

I haven't heard anything like this, Mr. Jan. To be honest, by the second paragraph the writer contradicts himself, and I had to figure out he uses "damascus" and "wootz" interchangeably. That's like interchanging "stainless steel" and wootz.

I thought the placement of carbon atoms among the iron atoms was well established.

I couldn't find much to corroborate these findings.

Not saying this is wrong, but it seems unlikely.

[Jan]

Mr. Mark, brief communication provided by the researchers can be found here: https://www.researchgate.net/publication...scus_sabre
 
The original paper, Reibold M., et al. Nature, 444. 286 (2006), is not free available, but I have found an article with similar content. If you are interested in further details see the attachment.


  [2009] Discovery of Nanotubes in Ancient Damascus - Marianne Reibold.pdf (Size: 1.74 MB / Downloads: 6)

[Jan]

The results of German researchers concerning the carbon nanotubes in historical Damascus blades are very exciting. This discovery goes beyond many famous metallurgical studies* done before the year 2k, because at that time it was not possible to resolve such a tiny structures.

Carbon nanotubes have cylindrical form, are made of carbon atoms and belong to strongest known materials. Some its mechanical properties are more similar to diamond than a carbon steel. It is not clear how the ancient blacksmiths produced those carbon nanotubes.

The German research has shown that the malleable nanotubes protect hard but fragile cementite nanowires. The historical Damascus blades can be viewed as composite material at nanoscale.

If you imagine that the ends of those nanotubes are exposed at blade's edge, than the myth concerning its self-sharpening does not sound so impossible.
 
*P.S.:
  [2001] The mystery of damascus blades - J. Verhoeven.pdf (Size: 534.52 KB / Downloads: 3)

[Mark Reich]

Hi Mr. Jan, I really haven't been avoiding this subject, but like most people around here, this is the busiest time of year for me.  

Thank you for introducing this information. It is interesting material. 

I have studied everything you've provided and many things related. I must admit, I had to come back to this several times, and studied for more than a few hours.

Although the original study has been cited many times in the past decade, I really don't know if it has been accepted by the metallurgic community. It seems like it's still a gray area.

It is surprising to me that we still can't figure out how to duplicate this ancient material, but I can understand why it's more important to continue to push the envelope of modern steel. Even if we could duplicate original wootz, it would be a giant step backward in steel technology. 

New things could come of it, and I sure hope one of them would be figuring out how to create steel with full carbon nanotube structure. Maybe they really would stay sharp forever! 

[Jan]

Thanks for your response Mr. Mark, please feel free to arrange the answers to time convenient to you. I am really not impatient.

Similar to you, I have also pondered why the German research has not started much broader discussion. You may be correct that it has not been accepted by the metallurgic community.

The reason for the hesitation of the metallurgical community in accepting these surprising results may also be the fact, that the German team was composed of material scientists and not steel experts.