Dynamics in Cu46Zr42Al7Y5 melts: Interplay between packing density and viscosity

Viscosity and density measurement methods for polymer melts

In this article review of density and viscosity measurement methods is presented, including ultrasonic pulse echo methods, which are capable to measure these properties of polymer melts. The methods are presented according to measurement principles, methodology, accuracy and possibility to measure density and viscosity of polymer melts on-line during extrusion process. Such measurements are ver...

Viscosity and Anelasticity of Melts

is the Maxwell relaxation time [24]. This relaxation time is a convenient approximation to the timescale of deformation where the transition from purely viscous behavior to purely elastic behavior occurs. The purely viscous response of a silicate melt is termed “liquid” behavior whereas the purely elastic response is termed “glassy” behavior. The term silicate melt is used to describe molten si...

Viscosity models for silicate melts

Rheology of silicates (melts or super cooled as glasses) is one of the most important fields to mankind, as geological activity largely influences life. In this paper, unifying empirical models for the Non-Newtonian shear viscosity and the extensional viscosity are proposed. The models have only one parameter, the zero shear viscosity (the Newtonian plateau), and are valid for a vide range of c...

Viscosity overshoot in the start-up of uniaxial elongation of low density polyethylene melts

Pressure Dependence of Viscosity of Glassforming Melts

We suggest a model in which viscosity η is related to entropy of the system. The model successfully describes the dependence of viscosity on pressure. A master equation is developed that allows a comparison of data obtained at different temperatures. Earlier, in the framework of the same model we described the dependence of viscosity on temperature. The present treatment gives a simple interpre...