Mineral-phase evolution and sintering behavior of MO–SiO2–Al2O3–B2O3 (M = Ca, Ba) glass-ceramics by low-temperature liquid-phase sintering

In this work, network former SiO2 and network intermediate Al2O3 were introduced into typical low-melting binary compositions CaO·B2O3, CaO·2B2O3, and BaO·B2O3 via an aqueous solid-state suspension milling route. Accordingly, multiple-phase aluminosilicate glass-ceramics were directly obtained via liquid-phase sintering at temperatures below 950°C. On the basis of liquid-phase sintering theory, mineral-phase evolutions and glass-phase formations were systematically investigated in a wide MO–SiO2–Al2O3–B2O3 (M = Ca, Ba) composition range. The results indicate that major mineral phases of the aluminosilicate glass-ceramics are Al20B4O36, CaAl2Si2O8, and BaAl2Si2O8 and that the glass-ceramic materials are characterized by dense microstructures and excellent dielectric properties.