Material slicker than Teflon discovered by accident
* 16:28 21 November 2008 by Kurt Kleiner
A superhard substance that is more slippery than Teflon could protect mechanical parts from wear and tear, and boost energy efficiency by reducing friction.
The "ceramic alloy" is created by combining a metal alloy of boron, aluminium and magnesium (AlMgB14) with titanium boride (TiB2). It is the hardest material after diamond and cubic boron nitride.
BAM, as the material is called, was discovered at the US Department of Energy Ames Laboratory in Iowa in 1999, during attempts to develop a substance to generate electricity when heated.
BAM didn't do that, but was found to have other desirable characteristics. "Its hardness was discovered by accident. We had a terrible time cutting it, grinding it, or polishing it," says Alan Russell, a materials scientist at Iowa State University in Ames.
Those chance findings have now developed into a $3-million programme at the Ames Lab to develop the BAM into a kind of eternal lubricant, a coating for moving parts to boost energy efficiency and longevity by reducing friction.
BAM is much slipperier than Teflon, with a coefficient of friction of .02 compared to .05. Lubricated steel has a friction coefficient of 0.16.
One way to exploit this slipperiness is to coat the rotor blades in everyday pumps used in everything from heating systems to aircraft, says Russel. A slick BAM coating of just 2 microns (see image, top right) could reduce friction between the blades and their housing, meaning less power is needed to produce the same pumping power.
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