Wings of steel

摘要

Alot of tosh is talked about "nano-technology", much of it designed to separate unwary investors from their hard-earned cash. This does not mean, though, that controlling the structure of things at the level of nanometres (bil-lionths of a metre) is unimportant. In materials science it is vital, as a paper just published in Nature, by Hansoo Kim and his colleagues at the Pohang University of Science and Technology, in South Korea, demonstrates. By manipulating the structure of steel on a nanometre scale, Dr Kim has produced a material which has the strength and the lightness of titanium alloys but will, when produced at scale, cost a tenth as much. Steel is useful because it is strong and cheap. But it is also heavy. It has, therefore, always been useless for applications such as aircraft. In a world that demands the ever-more efficient use of fuel in motor cars and lorries, it is now falling out of favour there, too. According to Dr Kim, the share by weight of steel in an average light vehicle fell from 68.1% in 1995 to 60.1% in 2011.