Al2O3对铋硼酸盐玻璃结构和性能的影响

Effect of Al2O3 on the Structure and Properties of Bismuth Borate Glass

通过FTIR、Raman、27 Al NMR、XRD、DSC等测试方法,研究了Al2O3含量对Bi2O3-B2O3-ZnO-SiO2-Al2O3系统低熔点封接玻璃结构及热性能的影响。结果表明:玻璃转变温度及软化温度随着Al2O3含量的增加逐渐降低。当Al2O3含量≤3%时Al2O3在玻璃中主要以[AlO4]四面体结构存在,充当网络结构形成体,热膨胀系数减小;当Al2O3含量>3%时Al2O3在玻璃中主要以[AlO6]八面体结构存在,破坏玻璃网络结构,热膨胀系数增大。当Al2O3含量为7%时,样品析出ZnAl2O4晶体,热膨胀系数随之减小。综上所述,当Al2O3含量为3%时,该系统低熔点玻璃具有较低的特征温度及较低的热膨胀系数且可避免高铋含量玻璃的析晶。

The effect of Al2O3on the structure and thermal properties of low-melting sealing glass(Bi2O3-B2O3-ZnOSiO2- Al2O3)was investigated by FTIR,Raman,27Al NMR and DSC.The results show that the glass transition temperature and softening temperature decrease as the content of Al2O3increases.When Al2O3content is less than or equal to 3%,Al2O3 mainly exists as[AlO4]tetrahedron in the glass,which acts as network structure forming units and decreases the thermal expansion coefficient;when more than 3%,[AlO6]octahedron becomes the main phase in the glassy structure,destroying the network structure,and declining the thermal expansion coefficient.ZnAl2O4crystal precipitates and the thermal expansion coefficient decreases when Al2O3content is 7%.In summary,not only low characteristic temperature and low mean coefficient of thermal expansion can be obtained when the addition of Al2O3content is 3%in the low-melting glass,simultaneously but also can prevent crystallization of high bismuth-bearing glass.