Mechanical and corrosion properties of Ti-35Nb-7Zr-xHA composites fabricated by spark plasma sintering
(1. School of Materials Science and Engineering, Kunming University of Science and Technology, Kunming 650093, China;
2. Engineering Technology Research Center of Titanium Products and Application of Yunnan Province, Kunming 650093, China;
3. Institute for Complex Materials, IFW Dresden, Dresden D-01171, Germany;
4. Institute of Materials Science, TU Dresden, Dresden D-01062, Germany)
2. Engineering Technology Research Center of Titanium Products and Application of Yunnan Province, Kunming 650093, China;
3. Institute for Complex Materials, IFW Dresden, Dresden D-01171, Germany;
4. Institute of Materials Science, TU Dresden, Dresden D-01062, Germany)
Abstract: To improve the bioactivity of Ti-Nb-Zr alloy, Ti-35Nb-7Zr-xHA (hydroxyapatite, x=5, 10, 15 and 20, mass fraction, %) composites were fabricated by spark plasma sintering. The effects of the HA content on microstructure, mechanical and corrosion properties of the composites were investigated utilizing X-ray diffraction (XRD), scanning electron microscope (SEM), mechanical tests and electrochemical tests. Results show that all sintered composites are mainly composed of β-Ti matrix, α-Ti and metal-ceramic phases (CaO, CaTiO3, CaZrO3, TixPy, etc). Besides, some residual hydroxyapatites emerge in the composites (15% and 20% HA). The compressive strengths of the composites are over 1400 MPa and the elastic moduli of composites ((5%-15%) HA) present appropriate values (46-52 GPa) close to that of human bones. The composite with 15% HA exhibits low corrosion current density and passive current density in Hank’s solution by electrochemical test, indicating good corrosion properties. Therefore, Ti-35Nb-7Zr-15HA composite might be an alternative material for orthopedic implant applications.
Key words: titanium composite; spark plasma sintering; microstructure; mechanical properties; corrosion properties