Microwave sintering of porous Ti–Nb-HA composite with high strength and enhanced bioactivity for implant applications

In the present study, high order porous Ti–Nb(50-x)-HA(x) (x = 0,10,20 wt %) composites have been fabricated for orthopedic application by using powder metallurgical route consisting temporary space alloying and rapid microwave sintering process. Structural porosity, elastic modulus, compressive str...
Ausführliche Beschreibung

In the present study, high order porous Ti–Nb(50-x)-HA(x) (x = 0,10,20 wt %) composites have been fabricated for orthopedic application by using powder metallurgical route consisting temporary space alloying and rapid microwave sintering process. Structural porosity, elastic modulus, compressive strength, corrosion resistance, and in-vitro bioactivity of as-sintered Ti–Nb-HA composites were studied. Results showed that the reinforcement of the HA assists in the formation of structural porosity, which reduced the elastic modulus. Porous Ti–Nb (with HA 10–20% content) composite possessed 40–60% structural porosity with a pore size of 150–260 μm and exhibited elastic modulus in the range of 12.5–29 GPa (near to human bone 8–20 GPa), which overcome the problem of stress shielding. The as-sintered composite not only possessed low elastic modulus but also exhibit high compressive strength (205–395 MPa). The alloying of HA improved the corrosion resistance and the protective efficiency of Ti–40Nb-10HA and Ti–30Nb-20HA composites was measured 40% and 72%, respectively higher than the Ti–Nb composite. In-vitro biological evaluation tests confirmed that the developed composites are non-cytotoxic and porous structure provides a vehicle for cell adhesion and growth. Moreover, various biocompatible phases such as Ca3(PO4)2 (known as TCP), Ti5P3 and CaO were developed, which helped in cell proliferation and differentiation. High biological activities were found on the Ti–30Nb-20HA composite have when compared with the Ti–Nb and Ti–40Nb-10HA composite and could be used as a potential biomaterial for the various possible orthopedic applications. Ausführliche Beschreibung