Permalink : http://hdl.handle.net/2115/38151

JaLCDOI : 10.14943/gbhu.72.159

Viscosity evaluation model by Goto (1997) has been re-examined using 608 viscosity data for 37 samples from literature. The model gives viscosity (η) of multicomponent silicate melts using Williams -- Landel -- Ferry (WLF) equation: logη = logηTg + A(T-Tg)/(B+T-Tg) {ηTg: viscosity at glass transition temperature; A, B: adjustable constants; T: temperature; Tg: glass transition temperature} Although used samples were only seven to formulate compositional dependency/independency of four parameters in WLF equation, by measuring viscosity and glass transition temperature, this model has successfully evaluated the viscosity from literature in wide range of temperature and chemical composition. Compared to other well-accepted viscosity model published in 2003, the accuracy of Goto model is almost equal overall, or seems to be higher in that it does not evaluate extremely different viscosity from the empirically determined value. This universality may be due to the application of compositional parameter from classical viscosity model that gives satisfactory evaluations for magmatic silicate melts in wide range of chemical composition at high temperature, and theoretical base of WLF equation.