High-Temperature Mechanical and Dynamical Properties of γ-(U,Zr) Alloys

Jiang-Jiang Ma; Xue-Fen Han; Xiao-Xiao Cai; Ruizhi Qiu; Olle Eriksson; Ping Zhang; Bao-Tian Wang

doi:10.3390/ma16072623

High-Temperature Mechanical and Dynamical Properties of γ-(U,Zr) Alloys

Materials (Basel). 2023 Mar 26;16(7):2623. doi: 10.3390/ma16072623.

Authors

Jiang-Jiang Ma^{1

2

3}, Xue-Fen Han^{1

2

4}, Xiao-Xiao Cai^{1

2}, Ruizhi Qiu⁵, Olle Eriksson⁶, Ping Zhang^{7

8}, Bao-Tian Wang^{1

2}

Affiliations

¹ Institute of High Energy Physics, Chinese Academy of Sciences (CAS), Beijing 100049, China.
² Spallation Neutron Source Science Center (SNSSC), Dongguan 523803, China.
³ School of Physics and Information Engineering, Shanxi Normal University, Taiyuan 030031, China.
⁴ University of Chinese Academy of Sciences (UCAS), Beijing 100049, China.
⁵ Science and Technology on Surface Physics and Chemistry Laboratory, Mianyang 621908, China.
⁶ Department of Physics and Astronomy, Materials Theory, Uppsala University, Box 516, SE-75120 Uppsala, Sweden.
⁷ School of Physics and Physical Engineering, Qufu Normal University, Qufu 273165, China.
⁸ Institute of Applied Physics and Computational Mathematics, Beijing 100088, China.

Abstract

High-temperature body-centered cubic (BCC) γ-U is effectively stablized by γ-(U,Zr) alloys that also make it feasible to use it as a nuclear fuel. However, relatively little research has focused on γ-(U,Zr) alloys due to their instability at room temperature. The effect of Zr composition on its mechanical properties is not clear yet. Herein, we perform molecular dynamics simulations to investigate the mechanical and dynamical stabilities of γ-(U,Zr) alloys under high temperatures, and we calculate the corresponding lattice constants, various elastic moduli, Vickers hardness, Debye temperature, and dynamical structure factor. The results showed that γ-U, β-Zr, and γ-(U,Zr) are all mechanically and dynamically stable at 1200 K, which is in good agreement with the previously reported high-temperature phase diagram of U-Zr alloys. We found that the alloying treatment on γ-U with Zr can effectively improve its mechanical strength and melting points, such as Vickers hardness and Debye temperature, making it more suitable for nuclear reactors. Furthermore, the Zr concentrations in γ-(U,Zr) alloys have an excellent effect on these properties. In addition, the dynamical structure factor reveals that γ-U shows different structural features after alloying with Zr. The present simulation data and insights could be significant for understanding the structures and properties of UZr alloy under high temperatures.

Keywords: dynamical structural factor; mechanical properties; thermodynamic stability; γ-(U,Zr).

Grants and funding

The authors gratefully acknowledge financial support from the National Natural Science Foundation of China (Grant Nos. 12204482, 12074381, 12075266 and 22176181), Science Challenge Project (Grant No. TZ2016001), Guangdong Basic and Applied Basic Research Foundation (Grant No. 2021A1515110587), and the Foundation of Science and Technology on Surface Physics and Chemistry Laboratory (Grant No. WDZC202101). The author O.E. acknowledges support from the Swedish Research Council (VR), the Knut and Alice Wallenberg (KAW) foundation, STandUPP, and eSSENCE. The authors are also thankful computational resources from the Supercomputer Centre of the China Spallation Neutron Source.