Lu Hao, Zhou Chang, Song Yuzhu, Zhang Yuanpeng, Wu Yiming, Long Feixiang, Yao Yonghao, Hao Jiazheng, Chen Yan, Yu Dunji, Schwiedrzik J Jakob, An Ke, He Lunhua, Lu Zhaoping, Chen Jun
Department of Physical Chemistry, Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing, China.
State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing, China.
Nat Commun. 2025 Jan 2;16(1):211. doi: 10.1038/s41467-024-55551-w.
Iron alloys, including steels and magnetic functional materials, are widely used in capital construction, manufacturing, electromagnetic technology, etc. However, they face the long-standing challenge of high coefficient of thermal expansion (CTE), limiting the applications in high-precision fields. This work proposes a strategy involving the in-situ formation of a nano-scale lamellar/labyrinthine negative thermal expansion (NTE) phase within the iron matrix to tackle this problem. For example, a model alloy, Fe-Zr10-Nb6, was synthesized and its CTE is reduced to approximately half of the iron matrix. Meanwhile, the alloy possesses a strength-plasticity combination of 1.5 GPa (compressive strength) and 17.5% (ultimate strain), which outperforms other low thermal expansion (LTE) metallic materials. The magnetovolume effect of the NTE phase is deemed to counteract the positive thermal expansion in iron. The high stress-carrying hard NTE phase and the tough matrix synergistically contribute to the high mechanical properties. The interaction between the slip of lamellar microstructure and the slip-hindering of labyrinthine microstructure further enhances the strength-plasticity combination. This work shows the promise of offering a method to produce LTE iron alloys with high mechanical properties.
包括钢和磁性功能材料在内的铁合金广泛应用于基本建设、制造业、电磁技术等领域。然而，它们面临着热膨胀系数（CTE）高这一长期存在的挑战，限制了其在高精度领域的应用。这项工作提出了一种策略，即在铁基体中原位形成纳米级层状/迷宫状负热膨胀（NTE）相来解决这一问题。例如，合成了一种模型合金Fe-Zr10-Nb6，其CTE降低至铁基体的大约一半。同时，该合金具有1.5 GPa（抗压强度）和17.5%（极限应变）的强度-塑性组合，优于其他低热膨胀（LTE）金属材料。NTE相的磁体积效应被认为可抵消铁中的正热膨胀。高承载应力的硬NTE相和韧性基体协同作用，促成了高力学性能。层状微观结构的滑移与迷宫状微观结构的滑移阻碍之间的相互作用进一步增强了强度-塑性组合。这项工作显示出有望提供一种生产具有高力学性能的LTE铁合金的方法。
