Researchers from TU Wien in Austria and the Beijing University of Technology in China have unveiled a multi-metal alloy exhibiting almost no thermal expansion, a discovery with significant implications for aerospace and precision electronics.
Sergii Khmelevskyi from the Vienna Scientific Cluster (VSC) explains, "The higher the temperature in a material, the more the atoms move, necessitating more space, which increases the average distance between them." While thermal expansion is a common phenomenon, this new alloy counters that effect.
Invar, a known alloy of iron and nickel, demonstrates minimal thermal expansion due to its magnetic order, which diminishes as temperature rises, leading to contraction that compensates for thermal expansion. The research team utilized computer simulations to analyze atomic-level behavior, allowing them to understand this intricate process in detail. Their findings, published in the Journal of Physical Chemistry C in 2023, laid the groundwork for predicting behaviors in other materials.
The practical application of this research led to the development of a pyrochlore magnet, composed of zirconium, niobium, iron, and cobalt. This innovative alloy experiences a length change of merely one ten-thousandth of a percent over a temperature range exceeding 400 degrees Celsius. The variation in cobalt concentration within the material results in different responses to temperature fluctuations, enabling a precise balance in composition that achieves near-zero thermal expansion.
This advancement not only holds promise for enhancing the performance and reliability of aerospace components but also paves the way for innovations in high-precision electronics, where thermal stability is critical.