First-principles design and experimental validation of β-Ti alloys with high solid-solution strengthening and low elasticities

β-Ti alloys with high strengths and low elasticities are suitable for application in biomaterials. However, to date, a clear and quantitative alloy design strategy to achieve alloys with these properties has not been developed. Herein, we designed β-Ti alloys with the required properties by first-principles calculations with experimental validations. Based on the design, N, O, Si, and Zr were selected as solute elements to realize β-Ti alloys with high solid-solution (SS) strengthenings and low Young's moduli. Compared to β-Ti alloys with other solute elements, β-type Ti–35 at% Ta alloys containing the abovementioned solute elements and fabricated by powder metallurgy demonstrated higher ratio of SS strengthening to modification in Young's modulus, validating the prediction by first-principles calculations. Among the β-Ti alloys with these solute atoms, the β-Ti alloy with N exhibited significant SS strengthening with the highest ratio of strength to Young's modulus. We believe that computational screening similar to the one in this study is effective in developing high-performance materials.