High Temperature Resistance of High Alkali Auminosilicate Glasses

High temperature resistivity of high alkali aluminoilicate glasses at 600-1 625 ℃ is investigated in this paper.Experimental results show that the resistivity of glass melts increases with the K₂O/Na₂O ratio in an temperature range of 900-1 625 ℃.The temperature dependence agrees well with the Arrhenius law,which implies that the resistivity of the glass melt is controlled by ion migration.The investigation of the temperature dependent resistivity of high alkali aluminosilicate glasses show that the electric conductivity behavior of glass has a transition near 900 ℃,which indicates that the aggregation degree of glass network structure and the binding force of modifier ions have an effect on glass electrical resistivity,and the diffusion of alkali metal ions attributes to the electric conductivity above 900 ℃,the activation energy is between 50-65 kJ/mol;while the glass conductivity capacity is poor at 600-900 ℃,which is controlled by migration mechanisms of alkali metal ions,and the activation energy is 100-120 kJ/mol.