First-principles calculations atomic structure and elastic properties of Ti-Nb alloys

Elastic properties of Ti based \beta-alloy were studied by the method of the model structure first principle calculations. Concentrational dependence of Young modulus for the binary \beta-alloy Ti-Nb was discovered. It is shown that peculiarities visible at 15-18% concentrations can be related to the different Nb atoms distribution. Detailed comparison of the calculation results with the measurement results was done. Young modulus for the set of the ordered structures with different Nb atoms location, which simulate triple \beta-alloys Ti-29.7%Zr-18.5%Nb and Ti-51.8%Zr-18.5%Nb have been calculated. The results of these calculations allowed us to suggest the concentration region for single-phase ternary \beta-phase alloys possessing low values of Young's modulus.