Posted on 11/17/2006 2:38:03 PM PST by LibWhacker
Carbon nanotubes are no longer the proud boast of 21st century materials scientists. It appears their discovery was unwittingly pre-empted by mediaeval Muslim sword-smiths whose tough Damascus blades taught the Crusaders the true meaning of cold steel when they fought over the Holy Land.
Peter Paufler and colleagues at Dresden’s Technical University discovered carbon nanotubes in the microstructure of a 17th century Damascus sabre. Intriguingly, the nanotubes could have encapsulated iron-carbide nanowires that might give clues to the mechanical strength and sharpness of these swords.
To Europeans, Damascus steel blades seemed magical. Not only could they cut a piece of silk in half as it fell to the floor, they could cleave rocks and their own swords without losing sharpness. The problem facing sword smiths was how to produce steel that was both hard and malleable. Too much carbon and the steel is hard and brittle; too little and it is too soft and malleable to hold an edge when sharpened. Damascus steel blades were forged out of small pure cakes of steel containing around 1.6–1.7 per cent carbon, called wootz. Produced in India, wootz cakes were shipped to Damascus where expert sword smiths fashioned them into blades.
Steel that contains this amount of carbon forms plates of cementite (Fe3C) which, on its own, makes the steel brittle. However, during the forging process at around 800oC, small amounts of ‘impurities’ were added containing many first-row transition elements (such as V, Cr, Mn, Co, and Ni), tungsten, and some rare-earths. which together had the effect of forming the cementite into bands. This gave the blades great strength, malleability, and a distinctive wavy-band pattern known as a damask. The skill had been lost by the 18th century, when supplies of these ores and impurities ran out.
Micro-structural examination of the bands had previously shown they contained nanowires of Fe3C. Now, Paufler’s team has uncovered the presence of carbon nanotubes by exposing a small piece of a blade to corrosion by hydrofluoric acid, and examining the effects under a high resolution scanning electron microscope. In some remnants the researchers saw evidence of incompletely dissolved Fe3C nanowires, suggesting the nanotubes could have encapsulated the nanowires. This would not only have given the blades their renowned strength and sharpness, but also their characteristic banding pattern. ‘The nanotubes probably came from the addition of mandatory organic ingredients we know were added during wootz production, such as wood from the tree Cassia auriculata and leaves from Coltropis gigantean,’ said Paufler. ‘So, by empirically optimising their blade-treatment procedures, these craftsmen made nanotubes more than 400 years ago.’
I agree. It's like saying people who threw mud at each other were taking advantage of complex aluminosilicate cation sheet structures with an affinity for water, on purpose.
I don't think that's what it's saying.
They did create a superior steel for blades. They surely didn't call it nanotubes, and it was undoubtedly by trial and error.
But they did do it.
I don't buy this.
"poured goats milk from a container of unknown volume"
Or the hair from a camels chin mixed in a vat of persian mole piss produced the 8-track player.
To a point, they could. There was nothing particularly magical about it, but Damascus steel was better than virtually anything being produced in Europe at the same time. Their swords were impressive weapons, probably second only to the Japanese swordsmiths who created those incomparable katanas and wakizashis.
}:-)4
WTF? No bias here.
Exactly. Good point. I'm not certain, but I believe I have read about ancient Damascus swords of Indian origin that pre-dated the muslim invasions.
Ha....only great invention of the islamics...better head severing swords.
Me either. Although the original damascus recipe has been lost forever, that kind of claim has to be myth.
The Japanese developed a "patterned" sword steel by smelting iron ore with charcoal and then heating, pounding, folding and refolding resulting in welded layers that have a strength and spring associated with lamination. If nanotubes are produced in this process I don't know. But I do know Damascus steel originated in India and is still produced there today and called "wootz."
Until I see that demonstrated I won't believe this is more than folklore.
Likewise.
As usual, they stole it from somebody else. Curiously enough, the only technology they ever seem to steal is that intended for war. Or they steal non-war technology (like cell phones) and use it for killing. Great folks.
Even the Syrians outsourced to India.
I dunno... It sounds like the author expects 21st century materials scientists to share the credit for discovering carbon nanotubes with a bunch of illiterate Medieval head choppers. In science you don't get any recognition for making a discovery unless you know what it is you've "discovered" or produced.
I'm sure these blades were good, but they weren't that good.
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