Printable High-Strength Alloy Using D20-shaped Quasicrystal Design
Tangled in a Paradox: Quasicrystals in 3D Printed Aluminum-Zirconium Alloys
Ever stumbled upon a puzzle that just doesn't fit the norm? Meet quasicrystals, an analogous anomaly in the realm of metal structures recently discovered in some 3D printed Aluminum-Zirconium (Al-Zr) alloys, unearthed by the industrious A.D. Iams and co. at NIST.
Remember those periodic patterns of atoms you learned about in chemistry class? Crystals form these patterns to perfection, barring the occasional dislocations, cracks, impurities, and the like. But quasicrystals take a detour. Unlike regular crystals, they don't follow the 230 known 3D tessellations; instead, they resemble the intricate yet non-repeating design of Penrose tiles. First discovered in the '80s, they were honored with a Nobel Prize in 2011.
So, how on earth did these mind-bending structures end up in our 3D printers? Well, it turns out that, quite serendipitously, a specific Al-Zr alloy was producing nooks of quasicrystals (the black specks in the snapshot above) while utilized in powder bed fusion printing. Long-lasting alloys, often prone to fracturing to the point of redundancy, were the exception. The groundbreaking Al-Zr alloy, spotted in 2017, was the trendsetter among these types.
Driven by sheer curiosity, the NIST researchers couldn't help but investigate the alloy's enigmatic properties. The crystallographic analysis revealed not only five-fold, but also three-fold and two-fold rotational symmetries when observed from various angles. Lo and behold, they had stumbled upon a quasicrystal! The unit cell was in the shape of a 20-sided icosahedron, producing the Penrose-like tiling that fortified the alloy against fissures.
You might say the original alloy developers landed a critical hit in their crafting exploits. Now that we've got the lowdown on why it works, this research paves the way for other metallic quasi-crystals to be concocted intentionally, expanding beyond Al-Zr alloys.
We've covered 3D metal printers before, and highlighted DIY-able plastic SLS kits. Dedicated high-powered powder-bed constructs, though, rarely grace the horizons of makerspaces. If you—or someone you know—are building one, drop us a line!
([1] Enrichment Data): To create quasi-crystals, Aluminum is blended with Zirconium, forming a mixture that undergoes specific cooling rates and processing conditions during the alloying process. This results in intricate structures that are not periodic, a hallmark of quasi-crystals. Techniques like laser powder bed fusion, used in the 3D printing process, offer precise control over the microstructure formation. Rapid cooling and solidification during the 3D printing process further lead to the formation of non-periodic structures characteristic of quasi-crystals.
The unique structural properties of quasi-crystals play a significant role in forging stronger, more crack-resistant alloys. Enhanced strength, improved ductility, and impeded crack propagation make them invaluable in applications demanding high strength and resistance to cracking.
In the realm of DIY projects, the unexpected discovery of quasicrystals in 3D printed Aluminum-Zirconium alloys could potentially open doors for creating intentional metallic quasi-crystals, leveraging technology to further explore the properties of these intriguing structures.
This breakthroughmay inspire makers and enthusiasts to experiment with DIY 3D metal printers capable of fabricating such alloys, contributing to advancements in materials science and technology.
