Effect of oxygen content on microstructure, mechanical properties, and electronic properties of -Ti3Nb: A first-principles study

beta-Ti-Nb alloys have drawn widespread attention on account of their excellent mechanical properties, phase stability, and chemical performance. In this study, first -principles calculations are utilized to examine how the non-metallic element O affects the stability and mechanical characteristics of beta-Ti3Nb. The most remarkable result of the change from the lattice constants is that O induces alpha" phase structure. The computation results of the elastic modulus and phonon spectrum confirm the structural and dynamical stability of all the Ti-Nb-O solid solutions. In addition, the ideal tensile and shear strength in various directions are predicted by simulating tensile and shear deformations. The results indicate that the theoretical strength of beta-Ti3Nb is improved when maintaining O concentration within a certain range. Particularly, the 20 at% Ti-Nb-O system shows extraordinary shear strength and tensile strength. Finally, the bonding characteristics of the Ti-Nb-O systems under stress loading are analyzed by electronic structure. The results in this work have great significance for the design and application of Ti-Nb alloys.