Fabricating Honeycomb Titanium by Freeze Casting and Anodizing for Biomedical Applications

Herein, porous titanium materials with honeycomb pore structure are prepared by freeze casting. The effect of freezing temperature on the pore structure and mechanical properties is also investigated. As the freezing temperature decreases from −10 to −50 °C, the compressive strength decreases from 79.5 ± 9.2 to 55.0 ± 4.3 MPa, and then increases to 90.1 ± 4.4 MPa. Porous titanium with an average pore size of 111.3 ± 25.2 μm and porosity over 60% are obtained at −10 °C. And the porous titanium is observed to form a neatly arranged nanopore structure with an average pore size of 28.5 ± 2.8 nm on the surface after anodizing. These nanopore structures can promote MG‐63 cell adhesion and proliferation, thus improving the biocompatibility of porous titanium. Further, in the simulated body fluid culture experiment, culturing for 3 days can induce Ca²⁺ and PO₄³⁻ to nucleate and deposit on the surface of anodized porous titanium, while 7 days can deposit a lot of apatite on the surface. In contrast, no apatite deposition is observed on the surface of the porous titanium sample without anodizing. These prepared porous titanium materials with high porosity, large pore size, sufficient mechanical properties, good biocompatibility, and biological activity might be a potential biomedical material.