Porous bio-high entropy alloy scaffolds fabricated by direct ink writing

Porous tantalum-titanium-niobium-zirconium (Ta-Ti-Nb-Zr) bio-high entropy alloy (bioHEA) scaffolds are fabricated using direct ink writing 3D printing technology in this study. A composite ink is prepared using four metal powders as raw materials: Ta, Ti, Nb and Zr. Ink extrusion is used to build 3D scaf-folds with interconnected porous structures at room temperature, which are then sintered in a vacuum environment. The interdiffusion of metal elements yields porous bioHEA scaffolds with a body-centered cubic (BCC) structure. The fabricated scaffolds have uniform compositions with a significant alloying ef-fect and good biocompatibility. The scaffolds have a compressive strength of 70.08-149.95 MPa and an elastic modulus of 0.18-0.64 GPa, indicating that the mechanical properties can be controlled over a wide range. The scaffolds have a compressive strength close to that of human cortical bone and thus meet the requirements for porous structure characteristics and biological and mechanical properties of orthopedic implants.(c) 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.