Preparation of machinable bioactive mica diopside-fluoroapatite glass-ceramics

A fluorphlogopite based glass powder was added to a bioactive glass-ceramic in the system CaO-MgO-P 2 O 5 (Fe 2 O 3 )-SiO 2 in order to improve its machinability. The sinterability of compacted mixtures, their crystallisation behaviour during sintering and their mechanical properties were evaluated and compared with the extreme ends compounds. According to results, fluoroapatite crystallised as a new phase only in the mixtures of the two glasses, its constituents originated by counter diffusion of two glasses components. Fracture toughness and microhardness of the best sample were higher than twice of the fluorphlogopite glass-ceramic composition. The machinability of samples was evaluated by naked eye observation and determination of brittleness factor.