Could medieval swords have had a secret nanotech ingredient?

[Rach3]

In my recent thread, "PF'ers against bad science in journalism", Gokul made a cuutting remark about colloidal silver being labeled a "nanotech" product:

Hey! I just spent $75 on my last tube of nanotech toothpaste and $155 on my nanoengineered shampoo. Don't go about knocking nanoscience like that! I might take it personally.

I ran into a fascinating follow-up; a recent Nature paper finds that the medieval Damascus blades, whose construction remains a mystery, may owe some of their bizarre properties to carbon nanowires, formed in some unknown metallurgical process! (Disclaimer; the medieval blacksmiths had no clue about the nanoscale structure of their blades, lacking electron microscopes).

Materials: Carbon nanotubes in an ancient Damascus sabre

M. Reibold1,2, P. Paufler1, A. A. Levin1, W. Kochmann1, N. Pätzke1 and D. C. Meyer1

...Here we use high-resolution transmission electron microscopy to examine a sample of Damascus sabre steel from the seventeenth century and find that it contains carbon nanotubes as well as cementite nanowires. This microstructure may offer insight into the beautiful banding pattern of the ultrahigh-carbon steel created from an ancient recipe that was lost long ago.

http://www.nature.com/nature/journal/v444/n7117/abs/444286a.html

I can't access the full article from my home computer, but a news story describes it to laypersons:

Sharpest cut from nanotube sword

Carbon nanotech may have given swords of Damascus their edge.

...Materials researcher Peter Paufler and his colleagues at Dresden University, Germany, have taken electron-microscope pictures of the swords and found that wootz has a microstructure of nano-metre-sized tubes, just like carbon nanotubes used in modern technologies for their lightweight strength.

The tubes were only revealed after a piece of sword was dissolved in hydrochloric acid to remove another microstructure in the swords: nanowires of the mineral cementite.

Wootz's ingredients include iron ores from India that contain transition-metal impurities. It was thought that these impurities helped cementite wires to form, but it wasn't clear how. Paufler thinks carbon nanotubes could be the missing piece of the puzzle.

At high temperatures, the impurities in the Indian ores could have catalysed the growth of nanotubes from carbon in the burning wood and leaves used to make the wootz, Paufler suggests. These tubes could then have filled with cementite to produce the wires in the patterned blades, he says...

http://www.nature.com/news/2006/061113/full/061113-11.html

 

[Gokul43201]

(Disclaimer; the medieval blacksmiths had no clue about the nanoscale structure of their blades, lacking electron microscopes).

That bit was funny!

Anyway, see here : https://www.physicsforums.com/showthread.php?p=1167836#post1167836