Material world

A discovery by researchers in the US could speed the design of materials that approach the hardness of diamond yet remain supple enough to be worked like metal.

In a massive computer simulation involving 128 computer processors and nearly 19 million atoms, UW-Madison professor of materials science and engineering Izabela Szlufarska and colleagues at University of Southern California, have demonstrated the precise atomic mechanisms that explain why "nanostructured" ceramic materials, some of the hardest substances known, also exhibit unusual pliability.

Unlike other exceptionally hard materials, these advanced ceramics tend to bend rather than break, meaning they could be shaped into extremely long-lasting yet lightweight parts for everything from automobile engines and high-speed machining tools to medical implants in the body.

But they are also notoriously difficult to engineer, because they possess a grain structure that falls into the nano-size range of molecules and atoms.

"How to optimise their design is an open question," says Szlufarska, who is also a professor of engineering physics. "People have used a trial and error approach to make these materials harder. But there is still much to be understood as to why they are harder."