Preparation of p-TCP/TiO_2 Composite by Hot-pressing

摘要

In this work, tricalcium phosphate [TCP, β-Ca_3(PO_4)_2]/titania composite were prepared with different ratio of 75/25, 50/50 and 25/75 (HA/TiO_2, wt %). The TiO_2 and hydroxyapatite (HA) powders, as starting materials, were synthesized by precipitation and hydrothermal methods, respectively. The sintered bodies of β-TCP/TiO_2 composite were prepared by hot pressing at pressure of 30 MPa and temperature of 800-1000 ℃ for 30 min under the pressure of 30 MPa in N_2 atmosphere. During the sintering process, hydroxyapatite was decomposed to β-TCP and CaTiO_3 at elevated temperature because TiO_2 could accelerate the decomposition of hydroxyapatite. The hot-pressed composite with 98% of sintered density, showed high value of 1080 Hv in hardness, compared with the pure hydroxyapatite (600 Hv) before immersion in distilled water. Increasing sintering temperature led densification of the composite with moderately uniform microstructures. As increasing the amount of TiC>2, the surface of the composite was less damaged or dissolved.