Effect of ZrO2 Content on Structure and Properties of Bi2O3-B2O3-SiO2 Sealing Glass

Abstract

Bi2O3-B2O3-SiO2 sealing glass was firstly prepared by melting method. The effect of ZrO2 content on the phase composition, softening temperature, thermal analysis, acid resistance, microstructure and mechanical properties of sealing glass was studied by infrared spectra, X-ray diffraction analysis, thermal expansion coefficient testing, scanning electron microscopy and three-point bending testing. The results showed that when the ZrO2 content was less than 4%, crystal did not occurred in the glass sample, as it is known that when the ZrO2 content was equal to or more than 4%, ZrO2 crystal and α-Bi2O3 was found in the glass sample. \[BO3\], \[BO4\], \[BiO3\], \[SiO4\] and \[ZrO4\] groups are the main components of the sealing glass. When the ZrO2 content was less than 3% and with the increased amount of ZrO2, the softening temperature, transition temperature, acid resistance and bending strength of the glass sample increased, while its thermal expansion coefficient decreased. Meanwhile, when the ZrO2 content was 3%, softening temperature and transition temperature of the glass sample reached the maximum value of 510 ℃ and 562 ℃, respectively, while the thermal expansion coefficient reached the minimum value of 6.92×10-6 K-1, and the bending strength also reached the maximum value of 49 MPa. With the increase of ZrO2 content, the softening temperature, transition temperature, acid resistance and bending strength of the glass sample decreased, but its expansion coefficient increased.

Keywords: ZrO2,  Bi2O3,  sealing glass,  acid resistance,  expansion coefficients