Modelling the flow

Duke University materials scientists have developed a computer model of how a "quasicrystal" metallic alloy interacts with a gas at various temperatures and pressures. Their advance could contribute to wider applications of quasicrystals for extremely low-friction machine parts, such as ball bearings and sliding parts.

Quasicrystals, like normal crystals, consist of atoms that combine to form structures, like triangles, rectangles and pentagons, which repeat in a pattern. However, unlike normal periodic crystals, in quasicrystals the pattern does not repeat at regular intervals. So, while the atomic patterns of two crystalline materials rubbing together can line up and grind against one another, causing friction, quasicrystalline materials do not, and thus produce little friction.

Quasicrystalline metallic alloys are already used in a handful of commercial products, including as a coating for some non-stick frying pans because they combine the scratch- and temperature- resistant properties of a polymer such as Teflon with the heat conduction property of metals.