Glass - Back to the Future!



Presenting Author:
Ulrike Veit
<ulrikeveit@hotmail.com>

article posted 18 Jan 2016


Ulrike Veit

Field of studies: Material Sciences

January 2010 - Graduation with Diploma (equivalent. to MSc, overall grade "very good")

Since 02/2010 PhD student at the Otto-Schott-Institut für Materialforschung, in the work group of Prof. Rüssel.
Thesis title: "Development and investigation of properties of high-strength Calcium Oxide-Magnesium Oxide- Aluminum Oxide-Siliciumdioxide glasses"






Melting Peaks of CMAS-Glass Melts Determined via DTA

Ulrike Veit, Christian Ruessel

Otto-Schott-Institute of Materials Research,
Friedrich-Schiller-University Jena,
Fraunhoferstraße 6, 07743 Jena (Germany)


For the production of glass fibres, in most cases slowly crystallizing glasses are used. In a glass melt for the commercial production for reinforcement, glass fibres should not crystallize within the temperature range of drawing. Therefore the temperature difference ΔT between the liquidus temperature and the temperature at which the glass fibres are drawn should be chosen carefully to guarantee a smooth production process.



The liquidus temperature, the highest temperature where crystals are thermodynamically stable in contact with the melt, was determined using the differential thermal analysis. In earlier experiments, the melting peaks of the pre-crystallized glasses during heating with DTA were compared with the results of the liquidus temperatures measured by a gradient furnace 1.



The experiments had shown that the values of DTA were comparable to the results of the gradient furnace and differed mostly by less than 10 K from each other. Experiments with different grain and batch sizes were done in order to examine the effect on the melting point of the pre-crystallized glasses. Also the method was tested on another set of glasses to test the reliability of this method.



Reference:

1 U. Veit, Y. Houet, D. Laurent, C. Rüssel, Liquidus temperatures of calcium magnesium alumosilicate glass-forming compositions determined via gradient furnace and from the melting peak by differential thermal analysis, Thermochim. Acta, 618 1-5 (2015) doi:10.1016/j.tca.2015.08.033