Influence of non-homologous substitutions of chemical components on rheological properties and on isochomal workability of Silicate glass melts

Abstract

The glass melts of a non-homologous series were investigated with respect to flow behaviour and stress generadon behaviour as well as to workability by means of the cylinder compression method. The results show that the competition between the gross viscosity effect and the bonding strength of the dynamic glass melt structure extremely deterrnines the high-temperature tensile strength, σ_ts, the critical deformation rate hc, and by that the isochomal workability. The larger hc values are not always connected to a larger non-Newtonian flow effect or to a larger gross viscosity effect as it is usually the case for homologous series. However, the rule for homologous series that smaller Emax moduli, i.e. smaller stiffness and brittleness of a glass melt, are coupled to a better isochomal workability is also vahd for non-homologous series. The special connections between σ_ts, hc and deformation, Δh/h0, are analyzed.