Highly dense β-wollastonite (CaSiO3) with good mechanical property and bioactivity was fabricated by pressureless sintering at 1250 ~ 1300 oC and phase transition of α to β-wollastonite with MgSiO3. Starting pure α-wollastonite powder were prepared by solid state reaction, and MgSiO3 powder was added to α-wollastonite powder to induce the phase transition α to β- wollastonite over 1250 oC. Sintered wollastonite at 1250 oC with 5 and 10 wt% MgSiO3 were α + β phase and β phase respectively, and showed higher densification rate than that of α or β-wollastonite, which are almost the same as the theoretical density. Hardness and Young's modulus of sintered wollastonite were dependent on the apparent density and the amount of β-wollastonite. Young's modulus (78 GPa) of β-wollastonite added 10 wt% MgSiO3 was almost double time of sintered α- wollastonite. From the in-vitro test, β-wollastonite shows lower bioactivity in SBF solution and better mechanical property than α-wollastonite, and biphasic (α + β) wollastonite with 5 wt% MgSiO3 had good bioactivity in simulated body fluid solution.

Keywords: β-wollastonite, High density, MgSiO3, Phase transition, Biocompatibility.