Influence of preparing conditions on the hot‐pressed sintering of transparent polycrystalline fluorite ceramics

Abstract Transparent polycrystalline fluorite ceramics were manufactured from naturally occurring fluorite mineral by a hot‐pressed sintering method. Naturally occurring fluorite minerals were ball milled by a planetary milling equipment. The phase structures of powders were single cubic fluorite phase, and diameters of fluorite powders were decreased from 100 to 20 μm with increasing ball milling duration. Influence of ball milling duration and sintering temperatures on optical properties of polycrystalline fluorite ceramics were studied systematically to obtain the optimum manufacturing process. For the mineral powders after 1 hours ball‐milling, the polycrystalline ceramic hot‐pressed at 1050°C exhibited the highest optical transmission. For a 2.5 mm thickness polycrystalline ceramic, the highest optical transmission at 500 and 1500 nm were about 60.1% and 75.7%, respectively.