Use Of Kinetic Neutron Diffraction To Observe Crystallisation Of A Mica Based Glass Ceramic

The development of a microstructure of interlocking mica crystals of suitable volume fraction, size and aspect ratio is important in producing machinable glass ceramics for industrial and dental applications. This study uses kinetic neutron diffraction to monitor in real time the effect of a nucleation hold on the development of barium fluormica crystals in a glass ceramic during controlled heat treatments. Significant differences in the formation of the final monoclinic barium fluorphlogopite phase were evident when glass rods were subject to the two heat treatment regimes, including a lowering of onset temperature and the formation of a metastable orthorhombic mica phase during the nucleation hold.