Design and properties of novel Ti-Zr-Hf-Nb-Ta high-entropy alloys for biomedical applications

The novel high-entropy alloys (HEAs) with compositions of (Ti1/3Zr1/3Hf1/3)(15)(Nb1/2Ta1/2)(x) (x = 3, 5) for biomedical applications have been designed and synthesized, using the cluster formula approach. The present HEAs have a single body-centered-cubic (BCC) solid-solution structure and possess prominent mechanical properties of high compressive yield strength (834-890 MPa) and microhardness (287-293 Hv), large plasticity (>45%) under compression, as well as low Young's moduli (56-68 GPa). Also, these HEAs exhibit good biocorrosion resistance, as revealed by a low corrosion rate at the order of 10(-4) mm/year and the low passive current densities of 10(-2) - 10(-1) A/m(2), which are attributed to the formation of passive films consisting of Ti-, Zr-, Hf-, Nb-, and Ta- oxides. The high cell viability and proliferation of bone-forming MC3T3-E1 cells on the HEAs are comparable to those on the Ti-6Al-4V alloy, indicating their good biocompatibility. The present work demonstrates the great potential of these novel Ti-Zr-Hf-Nb-Ta HEAs for biomedical applications.

Automated summary

Novel high-entropy alloys (HEAs) with excellent mechanical properties and biocompatibility have been designed and synthesized for biomedical applications, demonstrating great potential in the field.