An ultrastrong niobium alloy enabled by refractory carbide and eutectic structure

ABSTRACT

Nb alloys with high strength and relatively low density are sought for high-temperature applications. However, due to strain softening, conventional Nb alloys often exhibit insufficient high-temperature strengths. Here we report a strategy to design a novel lightweight and thermally-stable Nb alloy by combining the notion of eutectics and refractory carbide. The resulting Nb₂MoWC_0.96 eutectic alloy exhibits a high-temperature specific compressive strength of 77.2 MPa/·cm³·g¹ at 1673 K with a retained engineering plasticity of 37.5%, both are notably higher than the existing Nb and Nb-containing alloys. This work demonstrates that both the strength and plasticity of Nb alloys can be further optimized with refractory carbide and eutectics.

GRAPHICAL ABSTRACT

IMPACT STATEMENT

Combining the notion of eutectics with refractory carbide makes high strength, large plasticity Nb alloy with good microstructural stability.

KEYWORDS:

• Niobium alloys
• refractory carbide
• eutectic structure
• mechanical properties
• strengthening mechanism

Acknowledgments

This work was financially supported by the Young Scientists Fund of the National Natural Science Foundation of China (No. 52001120), Hunan Provincial National Science Fund for Distinguished Young Scholars under grant number 2022JJ10015, the State Key Laboratory of Advanced Metals and Materials (No. 2021-Z09), University of Science & Technology Beijing, China. Q.Q.W. acknowledges the financial support from the Excellent Postdoctoral Innovative Talents Program of Hunan Province (No. 2021RC2043). P.X. was supported by Hunan Provincial Natural Science Foundation of China (2022JJ30146). Professor Jianghua Chen and Professor Cuilan Wu are appreciated for their kind support in research funding.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Competing interests

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Data and materials availability

All data are reported in the paper.

Additional information

Funding

This work was supported by the Young Scientists Fund of the National Natural Science Foundation of China [grant number 52001120].