The quasicrystals found in this study form the corners of 20-sided shape called an icosahedron. To prove that he found an icosahedron, Andrew Iams had to rotate the sample under his microscope to show that it had fivefold, threefold and twofold rotational symmetry. This animation shows these three views of an icosahedron, as well as what the crystals look like under the microscope from the three different angles.
Credit: J. Wang/NIST
Andrew Iams saw something strange while looking through his electron microscope. He was examining a sliver of a new aluminum alloy at the atomic scale, searching for the key to its strength, when he noticed that the atoms were arranged in an extremely unusual pattern. “That’s when I started to get excited,” said Iams, a materials research engineer, “because I thought I might be looking at a quasicrystal.”
Not only did he find quasicrystals in this aluminum alloy, but he and his colleagues at the National Institute of Standards and Technology (NIST) found that these quasicrystals also make it stronger. They published their findings in the Journal of Alloys and Compounds.
The alloy formed under the extreme conditions of metal 3D printing, a new way to make metal parts. Understanding this aluminum on the atomic scale will enable a whole new category of 3D-printed parts such as airplane components, heat exchangers and car chassis. It will also open the door to research on new aluminum alloys that use quasicrystals for strength.
What Are Quasicrystals?
Quasicrystals are like ordinary crystals but with a few key differences.
A traditional crystal is any solid made of atoms or molecules in repeating patterns. Table salt ..
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