Fabrication and biocompatibility evaluation of porous Ti-Nb-based biomaterials with space holder by rapid sintering

Biomaterials of titanium and its alloys are useful as implant materials in orthopaedic surgery. In this study, porous Ti-13wt%Nb-13wt%Zr biomaterials were successfully fabricated using powder metallurgy by adding 10-30 wt-% NH4HCO₃ as a space holder and TiH2 as a foaming agent to mixed and milled Ti-Nb-Zr powders. The alloy powders were consolidated by spark plasma sintering process at 1123 K under 30 MPa conditions. The effect of space holder content on the pore size and distribution of the Ti-13wt%Nb-13wt%Zr (TNZ) alloys was observed by optical microscopy and scanning electron microscopy. These microstructure observations revealed that the volume fraction of the pores increased with increasing space holder content. The pore size of the TNZ alloy changed from the 100 μm scale to the 10 μm scale with increasing milling time and space holder content in the TNZ powders. The porous TNZ alloys exhibited good biocompatibility.