Characterization of glass viscosity with parallel plate and rotational viscometry

Glass materials have been applied as insulators during hot extrusion of titanium- and nickel-based alloys to reduce the friction and thermal conduction in the Ugine-Séjournet process. In this research, parallel plate viscometry (PPV) and rotational viscometry (RV) tests were carried out to characterize the viscosity of glass materials such as lead-borate, potassium-lead-silicate, and potassium-sodium-lead-silicate, quantitatively. Herein, we propose a new equation that can be used to predict an extensive range of viscosities from the softening to the melting point. This equation demonstrates more accurate predictions compared with the conventional Vogel-Fulcher-Tamman (VFT), the Avramov&Milchev (AM) and the Mauro-Yue-Ellison-Gupta-Allan (MYEGA) equations.