Effect of magnesium on β-α phase transformation of wollastonite

抄録

Wollastonite is a calcium silicate (CaSiO₃) which has been widely studied as a ceramic raw material with its mechanical, insulative and bioactive properties. Since wollastonite undergoes crystal phase transition from β-CaSiO₃ to α-CaSiO₃, it is important to investigate the relationship between phase transition and material properties of wollastonite. In this study, Mg-doped wollastonite (β-Ca_1−xMg_xSiO₃) was synthesized, and quantitative phase analysis was conducted to reveal the effect of Mg on β-α phase transformation. As a result, when the phase transformation occurs at 1250 and 1300 °C, Mg dissolve in β-CaSiO₃ up to the solid solubility limits, forming β-Ca_0.94Mg_0.06SiO₃ and β-Ca_0.90Mg_0.10SiO₃, respectively. Additionally, since Mg hardly dissolves in α-CaSiO₃, the diffusion of Mg outward from β-CaSiO₃ crystal lattices slows down the rate of β-α phase transformation.