Design and mechanical damage behavior of radially gradient-controllable Ti6Al4V bionic porous bone scaffolds

Inspired by the striking structural resemblance between trabecular bone microarchitecture and the dendritic branching morphology, we propose a novel biomimetic bone scaffold design strategy that replicates tree-derived fractal architecture. Four distinct fractal-structured porous scaffolds were fabricated via Selective Laser MeltingSLM 3D printing technology using Ti6Al4V alloy. The porosity distribution, damage mode, and mechanical properties of these scaffolds were systematically investigated. Through systematic modulation of fractal dimension and branching parameters, biomimetic bone scaffolds with customizable pore architecture and spatial distribution characteristics can be precisely fabricated. The porosity of the biomimetic scaffold gradually increases from the outer to the inner region, mimicking the porosity distribution of native bone. The biomimetic scaffolds with third-order fractal exhibit excellent mechanical properties of high compressive damage resistance and low elastic modulus. The compressive damage evolution pattern of biomimetic porous scaffolds is highly consistent with that of natural bone. The fracture propagation path presents an approximately 45° angle relative to the scaffold axis, which endows the scaffold with enhanced axial load-bearing capacity. The bionic porous scaffold designed in this study achieves consistent porosity distribution and analogous mechanical responses with natural bone.