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Damascus steel was a type of steel used for manufacturing blades in the Near East made with wootz steel imported from India.〔 These swords are characterized by distinctive patterns of banding and mottling reminiscent of flowing water. Such blades were reputed to be tough, resistant to shattering and capable of being honed to a sharp, resilient edge. The steel is named after Damascus, a city in Syria. It may either refer to swords made or sold in Damascus directly, or it may just refer to the aspect of the typical patterns, by comparison with Damask fabrics (which are in turn named after Damascus). The original method of producing Damascus steel is not known. Because of differences in raw materials and manufacturing techniques, modern attempts to duplicate the metal have not been entirely successful. Despite this, several individuals in modern times have claimed that they have rediscovered the methods by which the original Damascus steel was produced.〔 The reputation and history of Damascus steel has given rise to many legends, such as the ability to cut through a rifle barrel or to cut a hair falling across the blade. A research team in Germany published a report in 2006 revealing nanowires and carbon nanotubes in a blade forged from Damascus steel. This finding was covered by ''National Geographic''〔(Legendary Swords' Sharpness, Strength From Nanotubes, Study Says ). ''National Geographic'' (2010-10-28). Retrieved on 2011-11-13.〕 and the ''New York Times''.〔Fountain, Henry. (2006-11-28) (Nanotechnology in Sabres From Damascus, a New Look at the Seafloor and Predicting Reef Damage ). ''New York Times'' Retrieved on 2011-11-13.〕 Although certain types of modern steel outperform these swords, chemical reactions in the production process made the blades extraordinary for their time, as Damascus steel was superplastic and very hard at the same time. During the smelting process to obtain Wootz steel ingots, woody biomass and leaves are known to have been used as carburizing additives along with certain specific types of iron rich in microalloying elements. These ingots would then be further forged and worked into Damascus steel blades, and research now shows that carbon nanotubes can be derived from plant fibers,〔Goodell, B, Xie, X., Qian, Y., Daniel, G., Peterson, M., and J. Jellison. 2008. Carbon nanotubes produced from natural cellulosic materials. Journal of Nanoscience and Nanotechnology. Vol 8, 2472-2474.()〕 suggesting how the nanotubes were formed in the steel. Some experts expect to discover such nanotubes in more relics as they are analyzed more closely.〔 ==History== Damascus blades were manufactured in the Near East from ingots of wootz steel that were imported from India, as well as Sri Lanka. Archaeological evidence suggests that the crucible steel process started in the present-day Tamil Nadu before the start of Common Era. The Arabs introduced the Indian wootz steel to Damascus, where a weapons industry thrived. From the 3rd century to the 17th century, India was shipping steel ingots to the Middle East. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Damascus steel」の詳細全文を読む スポンサード リンク
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