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

摘要

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.