Design and mechanical properties of Ti-6Al-4V topology optimization gradient porous bone implant via selective laser melting

摘要

The paper aims to design and manufacture gradient porous structures for medical implants through combining topology optimization method and selective laser melting (SLM) technology and evaluate their mechanical properties, in which porous structures are designed according to the force bearing condition of human's humerus by topology optimization and are fabricated by SLM after investigation of their manufacturability. The mechanical properties of Ti-6Al-4V were studied through microstructure analysis and tensile test. The elastic modulus of the porous structures with different porosities is measured and the gradient porous structures for implants are designed by Magics 21.0 software. The results showed phases α and β were formed in the microstructure of heat-treated SLM samples but not in that of as-built SLM ones. The mechanical properties of heat-treated SLM samples meet standard for medical implant. The elastic modulus of the porous structures decreased slightly with the increase of porosity. That of porous structures with porosity of 60% and 70% was comparable to that of cortical bone, while the 80% porous structure was to that of trabecular bone. That provides the potential for the design of gradient porous structures for medical implant.