Microstructure, mechanical property and corrosion behavior of porous Ti-Ta-Nb-Zr

In this paper, biomedical porous Ti-Nb-Ta-Zr with 40% porosity and 166 +/- 21 mu m macro-pore size was successfully fabricated by space holder method. The microstructure, Vickers hardness, compressive and electrochemistry behavior were studied. It results that a few second phases exist in beta matrix of the porous Ti-Nb-Ta-Zr. Its Young's modulus is 0.8 GPa, close to 0.01-3 GPa for trabecular bone. The total recovery strain ratio and pseudoelastic strain ratio are 8.8% and 2.7%, respectively. It fails mainly by brittle cleavage with the fan-shaped and smooth cleaved facets. Although, local ductile fracture by a few dimples and a small amount of transcrystalline fracture with the cleavage of similarly oriented laths in a colony are observed on the fracture surface. The impedance spectrum of porous Ti-Nb-Ta-Zr has the characteristics of half capacitive arc resistance, showing good corrosion resistance in SBF solution.