Properties Of Low Temperature Sealing Glasses In V₂O₅-TeO₂-X System

Comparing with other sealing materials, sealing glasses have many excellentproperties such as high chemical stability, heat resistance and high mechanicalstrength, so sealing glasses are widely used in the sealing fields of vacuum,micro-electronics automobile and aerospace. Lots of heavy metal （Pb, Cd, Hg, Tl）oxides which are always included in the traditional sealing glasses will damage theenvironment tremendously. With awareness of environmental protection increasing,lead-free or lead-low has become one of the main development directions of sealingglasses. In addition, with the development of science and technology, all kinds ofcomponents of optoelectronic are developing toward miniaturization, precision,integration and intelligentialize. Therefore, higher requirement is put forward tosealing glasses. In order to improve the properties of sealing glasses, low sealingtemperature also becomes one of the research goals. In conclusion, low lead （orlead-free） and low sealing temperature have become the study focus of sealingglasses.The thesis takes the industrialization of vacuum glass as background. Low meltingpoint sealing glasses in lead-free which are suitable for building toughened glass aredeveloped. Basing on the earlier investigation of V₂O₅-B₂O₃-TeO₂, a basic compositionwhich could realize lead-free and low temperature is chosen. A sample of sealingglasses with low melting point and low expansion coefficient is obtained byintroducing TeO₂, ZnO. Furthermore, properties of the glass system are investigated.Earlier research results of V₂O₅-B₂O₃-TeO₂ternary system glasses indicate thatwhen the mole ratio of V₂O₅and TeO₂is4to6, V₂O₅-TeO₂binary system glassespossess the lowest sealing temperature （335oC）, but high thermal expansion coefficient (166×10^-7 oC^-1). Basing on the composition above and keeping the mole ofV₂O₅and TeO₂for4to6,0.1%-4.0%GeO₂is added to prepare V₂O₅-TeO₂-GeO₂ternary system glasses. The preparation condition of the ternary system glass isoptimized by the investigation of glass property in detail. A sample ofV₂O₅-TeO₂-GeO₂ternary system glasses possessing a good thermal stability andaqueous durability is obtained, of which sealing temperature is325oC and thermalexpansion coefficient is107×10^-7oC^-1. Basing on the properties of above glass, inorder to decrease thermal expansion coefficient to meet the sealing demand ofvacuum glass,1%～9%ZnO is introduced to prepare V₂O₅-TeO₂-GeO₂-ZnO systemglasses. The study results of properties demonstrate that when adding5%ZnO, asample with good property of V₂O₅-TeO₂-GeO₂-ZnO system glasses is gained, ofwhich glass transition temperature is310oC, sealing temperature is380oC, thermalexpansion coefficient is87×10^-7oC^-1(the expansion coefficient of common toughenedbuilding glass is about90×10^-7oC^-1), which could match with the common toughenedbuilding glass.