Discussions

Scandium (Sc), as a microalloying element, demonstrates remarkable potential in tailoring the mechanical and biological performance of titanium-based biomaterials. In a recent study, the addition of only 0.5 wt% Sc to a metastable β-type Ti-39Nb alloy significantly improved both its elastic modulus and biocompatibility-key properties for load-bearing orthopedic implants.
Ti-39Nb-0.5Sc exhibited a reduced elastic modulus of 41.1 GPa, which more closely matches that of human bone compared to the 51.9 GPa of Ti-39Nb. Meanwhile, tensile strength increased from 510.5 MPa to 568.8 MPa. These mechanical enhancements are attributed to nanoscale Sc oxide precipitates that inhibit martensitic transformation during quenching. Microstructural analysis confirmed a reduced presence of α″ martensite and refined grain size (from 228.71 µm to 143.27 µm), facilitating improved mechanical uniformity.
Biocompatibility assays revealed enhanced MG-63 osteoblast adhesion and proliferation in vitro, and superior osseointegration in vivo-likely due to grain refinement and increased surface hydrophilicity. These effects collectively accelerate bone healing, making the Sc-doped alloy a promising candidate for next-generation implants.
This case highlights Scandium's unique role in simplifying alloy design while achieving dual performance optimization. It offers a cost-effective route for preparing advanced titanium alloys for biomedical applications without the need for complex processing or multiple alloying additions.