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

High-temperature body-centered cubic (BCC) [Formula: see text]-U is effectively stablized by [Formula: see text]-(U,Zr) alloys that also make it feasible to use it as a nuclear fuel. However, relatively little research has focused on [Formula: see text]-(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 [Formula: see text]-(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 [Formula: see text]-U, [Formula: see text]-Zr, and [Formula: see text]-(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 [Formula: see text]-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 [Formula: see text]-(U,Zr) alloys have an excellent effect on these properties. In addition, the dynamical structure factor reveals that [Formula: see text]-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.