Design, strength prediction of Ti35NbxSnyZrzMo alloys with low elastic moduli and experimental verification on their mechanical properties

Abstract

Based on the d-electron alloy design method and the average valence electron concentration theory, three kinds of metastable β-type Ti–35Nb-based alloys containing different quantities of Sn, Zr, and Mo alloying elements were designed, whose $$ \overline{Md} $$ = 2.45 eV and e/a = 4.24, and $$ \overline{Bo} $$ values = 2.869, 2.866, and 2.860, respectively. Meanwhile, a formula for predicting the solid solution strength of Ti–Nb-based alloys was developed using JMatPro software. The experiments show that the designed alloys are all composed of single β phase after solid solution treatment, the tensile strength of the alloys coincides well with that predicted by the formula (the relative error <4 %), and the elastic moduli decrease with $$ \overline{Bo} $$ values increasing. The Ti35Nb3.7Zr1.3Mo alloy has the biggest $$ \overline{Bo} $$ value (2.869) and the lowest elastic modulus (54 GPa) among the three designed alloys.