Synthesis and characterization of an open-pore toxic-element-free Ti-based bulk metallic glass foam for bio-implant application

A series of porous toxic-element-free Ti42Zr40Si15Ta3 bulk metallic glass with 13-54 vol.% porosity are produced via powder metallurgy by the space holder method. The amorphous nature, foam morphology, mechanical properties, electrochemical response in simulation body fluid and in-vivo biocompatibility responses are systematically investigated. Results show that these open-cell Ti-based bulk metallic glass foams (BMGFs) exhibit yield strength from 140 to 730 MPa and Young's moduli from 8 to 53 GPa, matching very well with the mechanical properties of human bone and the estimated data by theoretical models. Compared to the bulk metallic glass (BMG) of the same composition, the high exposed surface area of the produced Ti-based BMGFs exhibited higher current in the cyclic voltammetry (CV) and potential state tests. However, no specific peak corresponding to the oxidation or reduction response of the composition elements is found in the electrochemical test. Moreover, the six-month in-vivo tests in New Zealand white rabbits shows that the good osteo-integration between the newly growth bone and the implanted Ti-based BMGFs, making them promising new candidates for bio-implant applications in avoiding stress shielding or bio-unfriendly symptoms. (C) 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommondorg/licenses/by-nc-nd/4.0/).