Study of crystallization of leucite in glass matrix feldspar using DTA

Feldspathic glass-ceramics reinforced with leucite has been used to make dental prosthesis. Leucite grains were nucleated and grown from feldspathic glass frit powders with particle size smaller than 45 mum. Crystallization kinetic of leucite in the feldspathic glass matrix was investigated under non-isothermal conditions using differential thermal analysis (DTA). The techniques used on the samples characterization were: X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). From the results of DTA measurements was found the activation energy for the process of crystallization of leucite by Kissinger method, as (333 +- 57) kJ/mol, and the Avrami parameter. The Avrami parameter value indicated the predominance of surface crystallization in the glass.(author)