We present a novel route to fabricate 3D nanoporous α-Ti foams by dealloying of TiCu master alloy in solid state using Mg powders. Pure open-cell nanoporous α-Ti foams are fabricated with BET surface area of 34.4 ± 0.8 m2/g and pore size in the range of 2–50 nm. The dealloying using powders is a solid state chemical reaction process to form Cu2Mg phase and Ti/Mg nanocomposites. The constituent of Cu in the TiCu alloy was dissolved into Mg powders thanks to the kinetics of interface reaction and volume diffusion. The pore-forming mechanism is a solid-state interdiffusion process. The ligament coarsening is from 492 to 650 nm with increasing of the dealloying temperature. The hardness and elastic modulus in nanoporous α-Ti foam follow linear decay fit with ligament size increasing. Our results demonstrate a facile strategy for the fabrication of nanoporous Ti foams with novel nanostructures and tailored properties.

A novel sort of cellular titanium foam with the porosity of 86–90% and the main-pore size of 0.5–3.0 mm was successfully prepared. Such foam exhibited a compressive curve showing three regimes: the initial elasticity, the middle zigzag plateau, and the final “densification.” This “densification” presented a course that the broken pieces continually accumulated in those pores which were unbroken or not entirely broken. The fracture morphology suggested that the compressive failure was typically brittle for this titanium foam. The electromagnetic shielding performance was investigated in the radio wave frequency range (0.3–3000 MHz) for this foam, which showed an evident effectiveness with a good performance at low frequencies. On the whole, the effectiveness would be superior while the porosity of the sample was relatively small. It could be inferred that the present foam samples would perform their electromagnetic shielding mainly by the reflection loss mechanism in the low-frequency range, and give priority to the absorption loss mechanism at the upper-frequencies.