Processing of glass-ceramics in the SiO2–Al2O3–B2O3–MgO–CaO–Na2O–(P2O5)–F system via sintering and crystallization of glass powder compacts (original) (raw)

Glass-ceramics were produced by crystallization of glasses in the SiO 2 -Al 2 O 3 -B 2 O 3 -MgO-CaO-Na 2 O-F system. The experimental results showed that bulk glasses are prone to surface crystallization. Hence, crystallization of bulk glasses resulted in non-homogeneous crystalline materials, which comprised relatively coarse crystals. Therefore, processing was realized using glass-powder compacts. Maximum densification was reached at 700-750 8C. This interval is positioned at relatively lower temperatures than those often reported for similar sintered glass-ceramics. Doping with P 2 O 5 improved sintering behaviour and broadened sintering temperature range. Sintering between 750 and 800 8C resulted in materials, which exhibited dense crystalline microstructure and the maximum flexural strength. #