Application of Thermophysical Methods for Oxide/Silicate Glasses

摘要

Thermophysical methods are intensively used in the field of glass science and technology. However there are three distinctive levels of theirs application. For the routine glass production the measurements of selected glass and glass melt properties are regularly performed as a part of the quality control procedure or in case of some changes of the production technology. These may reside in some changes of raw materials, refractories, glass batch preparation, etc. At this level mainly the glass melt viscosity, glass transition temperature and linear coefficient of glass thermal expansion are measured. Another level of thermophysical measurements is connected with the development of finite element models (FEM) of the glass production technology. Here the increasing demands are observed with the increasing quality and complexity of the FEM models. These demands span from the measurement of the temperature dependence of glass melt density and viscosity (FEM modelling of the glass flow through the melting tank, buoyancy convection, etc.) to the need of correct mathematical description of glass melt viscoelastic properties raised by contemporary FEM models (e.g. FEM model of the float glass production). The specific feature of the thermophysical measurements realized on silicate/oxide glasses resides in the relatively high temperature range reaching commonly temperatures close to 1600°C.