Superman-like alloy defies laws of heat, withstands 400 Kelvin with zero expansion – Interesting Engineering

The pyrochlore magnet’s exceptional performance is due to its non-uniform structure.a day ago2 days ago2 days ago2 days ago2 days ago2 days ago2 days ago2 days ago2 days ago2 days ago3 hours ago4 hours ago6 hours ago6 hours ago8 hours ago9 hours ago10 hours ago10 hours ago11 hours ago11 hours agoMrigakshi DixitMetal usually expands when heatedTU Wien

 Things are known to expand when they get hot. Bridges, roads, and even the Eiffel Tower grow a little taller in the summer. The Eiffel Tower’s height changes by 10 to 15 centimeters between summer and winter due to thermal expansion. It’s taller in the summer when the metal is warmer and expands.However, this expansion can be a real problem for many technologies like precision instruments or spacecraft. That’s why scientists have been searching for a material that maintains a constant size regardless of temperature changes.One potential candidate is Invar — an iron-nickel alloy famous for its incredibly low thermal expansion. But the science behind Invar’s magic remained a mystery, until nowResearchers at TU Wien in Vienna teamed up with experimentalists at the University of Science and Technology Beijing to unravel Invar’s secret using computer simulations.Interestingly, this new understanding led to the development of a new superman-like strong alloy called a pyrochlore magnet. “The higher the temperature in a material, the more the atoms tend to move – and when the atoms move more, they need more space. The average distance between them increases,” explained Sergii Khmelevskyi from the Vienna Scientific Cluster (VSC) Research Centre at TU Wien. “This effect is the basis of thermal expansion and cannot be prevented. But it is possible to produce materials in which it is almost exactly balanced out by another, compensating effect,” Khmelevskyi added. The research began with an investigation into Invar’s unusual property of low thermal expansion. They found that its magnetic properties are the key to its stability.“The effect is due to certain electrons changing their state as the temperature rises. The magnetic order in the material decreases, causing the material to contract. This effect almost exactly cancels the usual thermal expansion,” said Khmelevskyi. This new theoretical framework based on simulations allowed scientists to predict and design materials that exhibit almost no change in size with temperature.With this new understanding, the team set out to create an even better material. And they succeeded. Researchers developed a new alloy, the pyrochlore magnet, which exhibits even less thermal expansion than Invar.The pyrochlore magnet exhibits incredibly stable dimensions across a wide temperature range of over 400 Kelvins (126.8 degrees Celsius). Interestingly, it changes by only “one ten-thousandth of one percent per Kelvin.”The Invar is made of two metals, but the pyrochlore magnet is composed of four: zirconium, niobium, iron, and cobalt. This more complex composition gives it an unprecedented ability to resist thermal expansion.“It is a material with an extremely low coefficient of thermal expansion over an unprecedentedly wide temperature range,” said Yili Cao from the Institute of the Solid State Chemistry of the University of Science and Technology Beijing, in a press release.This new alloy‘s exceptional thermal stability is due to its irregular, heterogeneous structure.Its composition varies throughout, with differing concentrations of elements like cobalt. This influences how different regions of the material respond to temperature changes. Moreover, it balances the material’s properties at each point to achieve near-zero overall thermal expansion.This new material is ideal for applications facing extreme temperature variations or requiring high precision. It could be used in aviation, aerospace, and advanced electronics.Stay up-to-date on engineering, tech, space, and science news with The Blueprint.By clicking sign up, you confirm that you accept this site’s Terms of Use and Privacy PolicyMrigakshi Dixit Mrigakshi is a science journalist who enjoys writing about space exploration, biology, and technological innovations. Her work has been featured in well-known publications including Nature India, Supercluster, The Weather Channel and Astronomy magazine. If you have pitches in mind, please do not hesitate to email her.16 hours ago17 hours agoa day agoa day agoPremiumIE PROFollow

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