Abstract: MgO-Al₂O₃-SiO₂ (MAS) glass-ceramics were prepared by sintering method. The effects of different Al₂O₃/SiO₂ mass ratios on the microstructure and physicochemical properties of MAS glass-ceramics were studied. The structure and surface morphology of parent glass and glass-ceramics were characterized by XRD, DSC, FTIR and FESEM. The density, mechanical properties, corrosion resistance, thermal properties and dielectric properties of glass-ceramics were tested. The results show that as the mass ratio of Al₂O₃/SiO₂ increases from 0.52 to 0.64, the glass transition temperature T_g of the parent glass increases and the crystallization peak temperature T_p of the parent glass decreases, promoting the precipitation of α-cordierite crystal phase. The density of the samples fluctuates in the range of 2.52~2.60 g/cm³, dielectric constant ε_r increases from 1.73 to 4.51, thermal expansion coefficient decreases from 4.46×10^-6 to 2.38×10^-6 ℃^-1, dielectric loss tan δ fluctuates in the range of 8.4×10^-3~3.7×10^-3, and the flexural strength fluctuates in the range of 80~120 MPa.

Key words: Al₂O₃/SiO₂, MgO-Al₂O₃-SiO₂, glass-ceramics, cordierite, dielectric property