Preparation process of a highly resistant wollastonite bioceramics using local raw materials

Wollastonite (CaSiO₃) is mainly used for traditional ceramics. In this study, wollastonite-based ceramics was obtained by solid state reaction. The starting powders were sintered at different temperatures (850–1,250 °C) for 2 h. Moreover, different amounts of B₂O₃ (0.5–5.0 mass%) have been added. A relative density of about 97% of the theoretical was reached for samples sintered at 1,050 °C for 2 h, containing 3 and 5 mass% B₂O₃. Excellent values of both three point flexural strength (343 ± 34 MPa) and micro-hardness (4.8 GPa) for samples containing 5 mass% B₂O₃, sintered at 1,050 °C for 2 h. Besides this, a relatively low mass loss ratio has been measured (1.1%) for wollastonite samples containing 5 mass% B₂O₃, sintered under the same conditions, after soaking in lactic acid for 9 days. Finally, the bioactivity of wollastonite by the possibility of formation of apatite on the surface of wollastonite immersed in simulated body fluid was confirmed.