Rheological properties of potassium barium borate glasses

Several series of potassium barium borate glasses have been investigated as to their rheological properties.It has been found, that all these glasses show deviations from ‘Newtonian’ behaviour below temperatures corresponding to viscosities of 10¹⁰ poises. The activation energies of viscous flow are linear in both the potassium and barium mole percentages.For the ternary systems the pre-exponential factors of the viscosities do not decrease considerably with increasing metal ion content, contratry to what has been found in binary systems.