Low-melting bismuth-borate glass: composition development

The properties of low-melting lead-free glass based on the system ZnO-Bi2O3-B2O3 with K2O, Al2O3, and SiO2 additions are studied experimentally and the results are presented. The complete spreading and softening temperature ranges are determined. The computed values of the CLTE and refractive indices of the glasses are presented. Conclusions are drawn concerning the structural state of the bismuth ions.