Additive manufacturing of bio-inspired multi-scale hierarchically strengthened lattice structures

The next-generation medical implants require locally customised biomechanical behaviour to echo the properties of hard tissues, making additive manufacturing (AM) an ideal route due its superior flexibility. AM titanium alloys with designed porosity is mainstream for artificial implants, which, however, hardly balance strength-modulus combination. Here a martensitic TiNi biomaterial low modulus and asymmetric mechanical that mimics human bones explored. functionally graded lattice structure (FGLS) bio-inspired by bone architecture processed AM. Bio-inspired FGLS shows much higher strength ductility than uniform despite having equivalent structural porosity. Post-process heat-treatments alter microstructure result in multi-scale hierarchically strengthened FGLS, offering one highest specific strengths (about 70 kN m/kg) among porous biometals, while keeping reasonable ductility. Besides, deformation in-situ monitored, together microscopic observations, reveal failure mechanism. better compatibility lattice, including density, tension/compression asymmetry, modulus, strength. findings highlight ability tailoring modulus-strength-ductility trade-off through hierarchical design. • Mechanically echoes behaviour. lattices can mimic natural properties. Graded achieves ultrahigh biometals. A created unique