The crystallization of some glasses, based on celsian-spodumene
glass-ceramics, was investigated by different techniques including
differential thermal analysis, optical microscope, X-ray diffraction,
indentation, microhardness, bending strengths, water absorption and density
measurement. The batches were melted and then cast into glasses, which were
subjected to heat treatment to induce controlled crystallization. The
resulting crystalline materials were mainly composed of ?-eucryptite solid
solution, ?-spodumene solid solution, hexacelsian and monoclinic celsian,
exhibiting fine grains and uniform texture. It has been found that an
increasing content of celsian phase in the glasses results in increased bulk
crystallization. The obtained glass-ceramic materials are characterized by
high values of hardness ranging between 953 and 1013 kg/mm2, zero water
absorption and bending strengths values ranging between 88 and 126MPa, which
makes them suitable for many applications under aggressive mechanical
conditions.