LAUSR

Abstract The structures and mechanical properties of Nb-Mo-Co(Ru) solid solutions for hydrogen permeation have been investigated by X-ray diffraction (XRD) analysis, pressure-composition-temperature (PCT) measurements, and three-point bending tests. The as-prepared Nb86Mo14, Nb86Mo7Co7, and Nb86Mo7Ru7 samples composed of Nb-based solid solutions with bcc structures were hydrogenated into their corresponding hydrides to give the NbH0.95 phases after hydrotreatment. The largest lattice deformations of the bcc structure and NbH0.95 phase were observed in the Nb86Mo7Ru7 sample. This sample possessed the highest hydrogen-diffusion coefficient value (2.32 × 10−9 cm/s), the lowest hydride formation enthalpy (−21.4 kJ/(mol·H2)), and the maximum force before and after hydrogenation. Overall, these results demonstrate that the addition of Ru improves hydrogen diffusion and enhances the mechanical properties of Nb86Mo14 alloy against hydrogen embrittlement.