Viscous Flow And The Viscosity Of Melts And Glasses

The viscosity (e.g. viscosity coefficient) is one of the most important properties of a flowing material, e.g. in the glass industry viscosity determines melting conditions, working and annealing temperatures, rate of refining, maximum use temperature, and crystallisation rate. In this article, a brief compendium of viscosity models for melts and glasses is given including recent data on viscous flow model based on network defects in which thermodynamic parameters of configurons - elementary excitations resulting from broken bonds - are found from viscosity-temperature relationships.