The influence of aluminum oxide on the thermal expansion, glass transition temperature, and viscosity of lithium and sodium aluminoborate glasses

The glass transition temperatures and thermal expansion coefficients below and above the glass transition range are determined for lithium and sodium aluminoborate glasses over a wide range of concentrations. The temperature dependences of the viscosity for sodium aluminoborate and certain lithium aluminoborate glasses are studied in the viscosity range 10(10.5)-10(5) P. The data obtained are compared with the results of earlier investigations into the properties of barium aluminoborate glasses. The composition dependences of the properties studied are interpreted in the context of possible changes in the boron and aluminum coordination.