Effect of Sintering Temperature on the Properties of Titanium-AluminaHydroxyapatite Composite Prepared by Spark Plasma Sintering

In the present study, spark plasma sintering (SPS) technique was used to fabricate Ti-Al2O3-HA composite. Powders were sintered at 40 MPa pressure for 5 min at 1200 and 13000C. Microstructural characterisation was carried out using scanning electron microscopy (SEM). Density, hardness, electrochemical impedance and polarization test were performed to evaluate the properties of the samples. The results showed that by increasing the sintering temperature from 1200 to 1300 0C the density of the samples increases and the apparent prosity decreases. Also with increasing temperature the hardness of the samples increased from 528HV to 612HV. The result of electrochemical impedance test showed the polarization resistance of the sample enhanced from 222 Ωcm2 to 996 Ωcm2 . Furthermore, according to polarization measurements, the corrosion current density was reduced from 16.35 μA/cm2 to 1.47 μA/cm2 . The improvement in the corrosion resistance was attributed to the reduction of prosity and the formation of stronger passive film on the sample surface with increasing sintering temperature.