The State Key Laboratory for Mechanical Behavior of Materials at Xi'an Jiaotong University (XJTU) has developed a ductile alloy capable of delivering a load-bearing performance in the ultra-high temperature range of 2,000 C to 2,400 ℃.

The research findings, titled Ductile alloys offering 100 MPa tensile strength at 2,400 ℃, have been published in the online version of the science journal Nature, providing a new approach to the development of next-generation ultra-high-temperature alloys.

Advancements in the aerospace sector place stringent demands on the load-bearing capacity of metallic structural materials in ultra-high-temperature environments. Some critical heat-resistant components operate at temperatures exceeding 2,000 C, far above the melting points of most metallic materials, including nickel-based superalloys.

Currently, only refractory metals hold promise for meeting these extreme service requirements. Among them, tantalum (Ta) alloys are one of the very few viable options due to their high melting point (~3,000 ℃) and excellent comprehensive properties. However, existing tantalum alloys suffer from insufficient high-temperature strength, making it difficult for them to bear loads in extreme environments.

The root cause is that metallic materials universally undergo high-temperature softening. When the service temperature reaches 0.5 to 0.6 T_m (T_m being the absolute melting point), accelerated diffusion causes significant evolution in the material's internal microstructure, degrading the strengthening mechanisms that work effectively at room temperature.

Furthermore, beyond possessing ultra-high-temperature strength, these alloys must also maintain good ductility near room temperature to meet the processing requirements for manufacturing components with complex shapes.

To address this bottleneck, the research team designed and fabricated a novel oxide dispersion-strengthened tantalum alloy (B-ODS Ta alloy). With a unique boron (B)-intervened in-situ oxidation reaction, the team effectively controlled the size and distribution of the secondary phase. The resulting alloy combines excellent room-temperature tensile ductility, ultra-high-temperature tensile strength, and exceptional thermal stability