β Zr-Nb-Ti-Mo-Sn alloys with low Young׳s modulus and low magnetic susceptibility optimized via a cluster-plus-glue-atom model

The multi-element Zr-based bio-alloys are optimized for reaching lower Young׳s modulus and magnetic susceptibility by introducing the cluster-plus-glue-atom model to realize the composition design. A general cluster formulas of [(Mo,Sn)-(Zr,Ti)14]Nbx (x=1, 3) was obtained from the model and alloy rods with a diameter of 3 mm were prepared by copper-mold suction-casting processing. The β structural stabilities of the designed alloys were studied by the valence electron concentration (VEC). Among the β-Zr alloys, the [(Mo0.5Sn0.5)-Zr14]Nb1 (Zr87.5Nb6.25Mo3.13Sn3.13 at%) and [(Mo0.5Sn0.5)-(Zr13Ti)]Nb1 (Zr81.25Nb6.25Ti6.25Mo3.13Sn3.13 at%) alloys, corresponding to the lower β stability limit, display lower Young׳s moduli (77-79 GPa), lowest magnetic susceptibilities (2.12×10−6-2.13×10−6 cm3 g−1), as well as higher Vickers hardness (288-311 HV).