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17 April 2014 12:48 pm ,
Vol. 344 ,
Officials last week revealed that the U.S. contribution to ITER could cost $3.9 billion by 2034—roughly four times the...
An experimental hepatitis B drug that looked safe in animal trials tragically killed five of 15 patients in 1993. Now,...
Using the two high-quality genomes that exist for Neandertals and Denisovans, researchers find clues to gene activity...
A new report from the Intergovernmental Panel on Climate Change (IPCC) concludes that humanity has done little to slow...
Astronomers have discovered an Earth-sized planet in the habitable zone of a red dwarf—a star cooler than the sun—500...
Three years ago, Jennifer Francis of Rutgers University proposed that a warming Arctic was altering the behavior of the...
- 17 April 2014 12:48 pm , Vol. 344 , #6181
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Ceramic or Silly Putty?
21 September 2001 7:00 pm
Materials scientists have developed a new ceramic that's closer to melted mozzarella than bathroom tiles. As reported in the 20 September issue of Nature, when heated the new material can be stretched to at least 10 times its original length without snapping. The ceramic is cheap to make and can be molded into shapes useful in engine parts and other industrial applications.
Fire clay in a kiln and the clay mineral crystals fuse, or sinter, together to form the characteristically hard, heat-resistant, and--oops!--tragically brittle stuff of pots, tiles, and teacups. Materials scientists have struggled to devise novel, malleable ceramics, but all attempts so far either crack when stretched or are impossibly slow to distort.
By homing in on how ceramics behave when stretched, Byung-Nam Kim and his colleagues at the National Institute for Materials Science in Tsukuba, outside Tokyo, hit on a new formulation using roughly equal amounts of powdered zirconium oxide, magnesium aluminate, and alumina. They mixed the three ingredients and heated them until they sintered. The resultant ceramic has a grainy structure that close-up looks like a honeycomb, which is central to the material's properties. With additional heating, the material can be stretched, because the 0.2-micrometer grains easily slide over one another without combining to form larger grains. "We think other kinds of ceramic powders ... will give the same results," says Kim.