Compositional effect on the crystallization of the cordierite-type glasses

The determination of apparent activation energies for the crystallization of P2O5/B2O3-containing cordierite-type glasses was conducted by non-isothermal differential thermal analysis (DTA). Glass with excesses both of SiO2 and Al2O3 has a higher activation energy for crystallization. In addition to the main phase of alpha -cordierite, several other phases (farringtonite, clinoenstatite, and forsterite) were detected in the fully crystallized samples by the X-ray powder diffraction technique. The crystallization behavior for the powdered glass was governed by the surface crystallization mechanism, which would not change with composition. (C) 2001 Kluwer Academic Publishers.