Rare Quasicrystals Found to Strengthen 3D-Printed Aluminum Alloys

Researchers at the National Institute of Standards and Technology (NIST) have discovered that a rare atomic arrangement known as quasicrystals can enhance the strength of aluminum alloys produced through metal 3D printing. The finding could lead to stronger, lighter parts in critical applications such as aircraft manufacturing and automotive engineering.

The team observed the formation of quasicrystals during the high-temperature process of powder bed fusion, a common 3D printing method where metal powder is melted by a laser and solidified layer by layer. These quasicrystals, which exhibit non-repeating atomic patterns with unique symmetries, were found to disrupt the regular structure of the aluminum alloy. This disruption impedes atomic movement within the metal, increasing its overall strength. The work is detailed in a paper published in the Journal of Alloys and Compounds.

The aluminum-zirconium alloy under examination was initially developed in 2017 to address the issue of cracking during metal 3D printing. Zirconium was added to the alloy to stabilize the printing process, but the exact mechanism behind its strength remained unclear. Through detailed microscopy, NIST scientists now attribute part of the alloy’s performance to the presence of quasicrystals, which had not been previously detected in this material.

Quasicrystals differ from conventional crystals in that they do not repeat their atomic pattern, even though they fill space completely. First discovered at NIST in the 1980s, quasicrystals were initially met with skepticism but were later confirmed, earning a Nobel Prize in Chemistry in 2011. The recent discovery continues this legacy, with NIST researchers once again identifying these unique structures—this time as a key to improved performance in 3D-printed metals.

The identification required precise microscopy, including capturing multiple rotational symmetries in the atomic pattern, such as fivefold, threefold, and twofold arrangements—signatures of an icosahedron-shaped quasicrystal. With this confirmation, researchers hope their findings will lead to the deliberate design of stronger aluminum alloys using quasicrystalline structures in future engineering applications.

Article by multiple RFHC contributors, based upon information from a National Institute of Standards and Technology press release.

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