Fabrication of Zirconia-Hydroxyapatite Composites for Biological Materials

Microstructure and mechanical behaviors of zirconia [ZR; ZrO2+3mol%Y2O3]–nano hydroxyapatite [HA; Ca10(PO4)6(OH)2] nanocomposites were studied. A pulse electric current sintering (PECS) method was applied to fabricate ZR-HA composites as biomaterials. The reaction between zirconia and hydroxyapatite was successfully avoided. It was a successful preparation of bioactive composites in the quasi-binary system Ca10(PO4)6(OH)2 + ZrO2. One of the most serious problems is that when a mixture of zirconia and nano-hydroxyapatite powders was sintered, extensive chemical reaction between zirconia and hydroxyapatite was unavoidable. By applying a novel super-fast consolidation technique, pulse electric current sintering (PECS), the deleterious reactions were inhibited kinetically. The specimens contain 0, 10, 20, and 30wt% of hydroxyapatite on zirconia as remainder. Samples were sintered using the PECS method at 1100°C , 1150°C, 1200°C, and 1250°C, with increasing 100°C /min, under a pressure of 50Mpa in vacuum atmosphere for 5min. Characterization of the samples was carried out using X-ray diffraction analysis at different sintering temperatures. Flexural strength was estimated with 3-point bending test. The relative density was acquired using an Archimedes method in toluene medium.