Effect of P ₂ O ₅ on evolution of microstructure of MgO–Al ₂ O ₃ –SiO ₂ glass ceramics

MgO–Al2O3–SiO2 (MAS) cordierite based glass ceramics were prepared by volume crystallisation. X-ray diffraction, Scanning electron microscopy and Energy diffraction scanning were used to investigate crystallisation behaviour and the influence of P2O5 on microstructure MAS based glass ceramics. The results showed that P5+ could promote the phase separation of MAS glass and that the glass was divided into two areas, such as Mg4Al2Ti9O25 and the containing P5+ area at <900°C. Mg4Al2Ti9O25 and Mg3(PO4)2 in the area were both advantageous to the precipitation of μ cordierite, which further transformed to α cordierite due to P5+ in the residual glassy phase. However, P5+ inhibited the presence of cordierite when the heat treatment temperature was >900°C.