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Influence of particle size of glass powder on the crystallisation kinetic parameters of a fluorophosphate glass

2000-04-01
Ozturk, A
Crystallisation behaviour of a fluorophosphate glass composed of the system AIF(3)-CaF2-Mg-2-Sr-2- BaF2-Ba(PO3)(2) was studied at nonisothermal conditions using differential thermal analysis (DTA). Kinetic parameters for crystallisation, namely, the activation energy, E, frequency factor; upsilon, and Avrami exponent, n, were determined as a function of the particle size of the glass powder and different furnace atmosphere. Also the Effect of flow rate of nitrogen gas on the crystallisation behaviour was studied Results are analysed in ter nu of a theory applicable to nonisothermal crystallisation kinetics. E, upsilon and n decreased as particle size of the glass powder increased. Furnace atmosphere and flow rate of nitrogen gas did not have a significant effect on the kinetic parameters.