Preparation and bioactive surface modification of the microwave sintered porous Ti-15Mo alloys for biomedical application

Biomedical porous Ti-15Mo alloys were prepared by microwave sintering using ammonium hydrogen carbonate (NH 4 HCO 3 ) as the space holder agent to adjust the porosity and mechanical properties. The porous Ti-15Mo alloys are dominated by β -Ti phase with a little α -Ti phase, and the proportion of α and β phase has no significant difference as the NH 4 HCO 3 content increases. The porosities and the average pore sizes of the porous Ti-15Mo alloys increase with increase of the contents of NH 4 HCO 3 , while all of the compressive strength, elastic modulus and bending strength decrease. However, the compressive strength, bending strength and the elastic modulus are higher or close to those of natural bone. The surface of the porous Ti-15Mo alloy was further modified by hydrothermal treatment, after which Na 2 Ti 6 O 13 layers with needle and flake-like clusters were formed on the outer and inner surface of the porous Ti-15Mo alloy. The hydrothermally treated porous Ti-15Mo alloy is completely covered by the Ca-deficient apatite layers after immersed in SBF solution for 14 d, indicating that it possesses high apatiteforming ability and bioactivity. These results demonstrate that the hydrothermally treated microwave sintered porous Ti-15Mo alloys could be a promising candidate as the bone implant.