Effects of ZnO and cordierite contents on the wetting properties of a Bi2O3-ZnO-B2O3 glass composite as a low-melting sealing glass

The wetting properties of Bi2O3-ZnO-B2O3 glass composite materials with different ZnO and cordierite contents were investigated upon melting them and thermally treating them at 1300 degrees C and 430 degrees C, respectively. The density of a 48%Bi2O3-24%ZnO-22% B2O3 glass composite was 7.30 g/cm(3), which is 99.3% of its theoretical density; its glass softening temperature was 413.2 degrees C. The addition of cordierite improved the adhesion of the glass by acting as a filler, thus lowering its coefficient of thermal expansion. Specifically, by adding 0-15% cordierite, the coefficient of thermal expansion of the Bi2O3-ZnO-B2O3 glass was reduced from 10.6 x 10(-6) to 7.5 x 10(-6) /K. X-ray diffraction and transmission electron microscopy studies confirmed that the glass was not crystallized, but rather a composite. This study demonstrates that the Bi2O3-ZnO-B2O3 glass composite developed herein is an environment-friendly lead-free material that can be sintered at 430 degrees C without losing its tempered glass function; therefore, this material shows promise for applications in architecture, electronic devices, and home appliances.