| Fluoroamphibole crystals are double chain structures with weak bonding between chains, they also readily cleave while machining, therefore, a fluoroamphibole glass-ceramic also shows a good machinability just like the fluoromica glass-ceramics.The conventional preparation for this machinable glass-ceramics is melting method, the method is an energy-intensive, relatively costly process because it requires vitrification of batch glasses and the melting temperature generally is above 1450℃. In this paper, we put forward a new route, adding fluorophlogopite crystal into soda-lime glass powder directly and sintering, to make the machinable fluoroamphibole glass-ceramics, therefore, it simplifies the process and reduces the cost.The sintered samples were characterized by SEM, XRD and EDAX in detail. The change of the microstructure and the crystal phases in the glass-ceramics after sintering at different temperature and time and the crystallizing mechanism of the fluoroamphibole glass-ceramics were researched. The effects of the fluorophlogopite content, size of glass powder, forming pressure and the sintering temperature on the properties of the glass-ceramics were studied too.The results show that the fluoroamphibole crystal is formed via an interaction between fluorophlogopite and soda-lime glass instead of precipitated from glass during sintering. The microstructures of the glass-ceramics consist of glassy matrixes, rod-like fluoroamphibole crystals and some pores. Fluoroamphibole crystal diameter increases with increasing of sintering temperature and extending of soaking time. While adding 35% fluorophlogopite, about 70% fluoroamphibole crystal is formed. As the fluorophlogopite addition increases, the density and strength of the glass-ceramics decrease, the machinability is improved. When the size of glass powder is mesh 130, the strength of samples is the highest. As the...
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