Pore structures and mechanical properties of porous titanium scaffolds by bidirectional freeze casting

- Porous titanium scaffold were fabricated by bidirectional freeze casting.
- The structure and composition of sample before and after sintering were compared.
- The structure of porous titanium was changed with different initial solid content.
- Porous titanium with lamellar structures show excellent mechanical property.

Porous titanium scaffolds with long-range lamellar structure were fabricated using a novel bidirectional freeze casting method. Compared with the ordinarily porous titanium materials made by traditional freeze casting, the titanium walls can offer the structure of ordered arrays with parallel to each other in the transverse cross-sections. And titanium scaffolds with different pore width, wall size and porosity can be synthesized in terms of adjusting the fabrication parameters. As the titanium content was increased from 15 vol.% to 25 vol.%, the porosity and pore width decreased from 67 ± 3% to 50 ± 2% and 80 ± 10 μm to 67 ± 7 μm, respectively. On the contrary, as the wall size was increased from 18 ± 2 μm to 30 ± 3 μm, the compressive strength and stiffness were increased from 58 ± 8 MPa to 162 ± 10 MPa and from 2.5 ± 0.7 GPa to 6.5 ± 0.9 GPa, respectively. The porous titanium scaffolds with long-range lamellar structure and controllable pore structure produced in present work will be capable of having potential application as bone tissue scaffold materials.