Melting, sintering and wetting properties of ZnO–Bi2O3–B2O3 sealing glass

Glasses based on ZnO−Bi2O3−B2O3 system are expected to be a new kind of sealing glasses because of their low melting temperature and other properties. In order to reveal the effect of B2O3 on the rheological behavior of ZnO−Bi2O3−B2O3 system glass melt, the properties of viscosity, thermal expansion, fluxion property and wetting process between cylinder samples and stainless steel were investigated with the rotating crucible viscometer, dilatometer and high-temperature microscope. The structure of sintered glass samples was investigated with scanning electron microscope. The results show that the B2O3 content increasing in B1−B3 at the given temperature between 400 °C and 500 °C leads to the increasing of the sample viscosity. When the amount of B2O3 increases from 5.24% to 9.24% (mass fraction), the coefficients of thermal expansion of glass samples decrease smoothly from 10.94×10−6 to 10.71×10−6 and 10.38×10−6 °C−1 respectively. In the case of sealing temperature, its value increases from 453 °C to 494 °C. ZnO−Bi2O3−B2O3 system low-melting glass powder sintering was with viscous liquid to participate, which could make the densification of glass sample more effective and more efficient. With the content of B2O3 increasing, the wetting angle between the glasses samples and stainless steel could also increase, and the resulting appropriate sealing temperature range is 460−490 °C.