First-principles study of the stability and mechanical properties for binary Mo–Re alloys

Mo–Re alloys are highly suitable as core materials in nuclear reactor applications due to their excellent radiation resistance, high melting point, superior mechanical strength, and low neutron absorption characteristics. In this study, we investigate the stability and mechanical properties of eight Mo–Re alloys by first-principles calculations, including Re24Mo5, ReMo3-1, ReMo3-2, Re3Mo2, ReMo, Re3Mo-1, Re3Mo-2, Re3Mo-3. The results of formation enthalpy, elastic stability criteria and phonon dispersion curves indicate that all Mo–Re alloys are stable except for the ReMo3-2. Subsequently, the mechanical parameters of the remaining seven Mo–Re alloys, including bulk modulus, shear modulus, Young's modulus, Poisson's ratio, B/G ratio, and anisotropy index are investigated. The bulk modulus of Re24Mo5 is the highest, at 344.597 GPa, the Young's modulus and shear modulus of Re3Mo-3 are the highest, measuring 390.617 GPa and 149.294 GPa, respectively. Furthermore, all Mo–Re alloys exhibit ductile characteristics. This study is of great significance for the selection of suitable Mo–Re alloys with sufficient mechanical strength for use as core materials.