Co-extrusion of internally oxidized Nb-1Zr: An avenue to new load-bearing implants

• Co-extrusion of pre-oxidized Nb-1Zr powder results in solid bodies with few defects. • High compression yield stress (829–937 MPa) was obtained upon heat treatment. • The material features no toxic elements and is a promising material for implants. Niobium-zirconium alloys like Nb-1Zr offer high biocompatibility and osteoconductivity, with a lower Young’s modulus than Ti-6Al-4V, but their strength is limited due to a coarse grain structure. In this study, alloy strength is enhanced through controlled internal oxidation. Pre-oxidizing Nb-1Zr powder at 620 °C for 0, 60, and 120 min prior to co-extrusion increased 0.2% offset compression yield stress from 829 to 937 MPa. The improved strength is due to a fine-grained structure and high dislocation density. Longer oxidation times increased brittle niobium oxides. Future work will refine oxidation to tailor the properties of these alloys for load-bearing implants.