摘要
以传统熔融冷却法制得了Li2O-ZnO-Al2O3-SiO2(LZAS)系统无色透明的基础玻璃,通过热处理获得了与4J29可伐合金封接用微晶玻璃材料。运用DTA、XRD等手段分析了组成和热处理制度对玻璃析晶和热膨胀行为的影响。结果表明,随ZnO取代(SiO2+Al2O3),NBO/T逐渐增大,第1、第3放热峰向低温方向偏移,第2放热峰则稍向高温方向偏移;对于24.5Li2O-15ZnO-8.55Al2O3-51.25SiO2-0.7P2O5系统玻璃来说,晶化温度对析出晶相的种类和含量影响显著,随晶化温度的升高,晶相变化表现出如下趋势:主晶相由方石英向Li2Al2Si3O10转变,次晶相由βⅡ/-Li2ZnSiO4向γ0-Li2ZnSiO4转变。这种变化也反映在热膨胀行为上,即随晶化温度升高,热膨胀系数在(40.2～123.6)×10-7/K之间变化。经535℃,2h和700℃,2h处理后获得的热膨胀系数为49.5×10-7/K,可满足与4J29可伐合金封接使用要求。
The homogeneous and colorless Li2O-ZnO-Al2O3-SiO2 system basic glasses were prepared by using conventional melt quenching technology and the glass -ceramics which can be used to seal with 4J 29 Kovar alloy were obtained through the processes of nucleation and crystallization. The compositional dependence of crystallization and thermal expansion behavior were studied by using DTA and XRD. The results show that, NBO/T value increases with substituting ZnO for （SiO2 ＋ Al2O3） ,the first and third exothermic peak shift towards lower temperature, whereas the second exothermic peak shifts slightly to higher temperature. As for the glass with composition 24.5Li2O - 15ZnO - 8.55Al2O3 - 51.25SiO2 - 0.7P2O5, obvious effects of crystallization temperature Tp on the type and content of the crystalline phase are observed. With increasing crystallization temperature the primary crystalline phase varies from cristobalite to Li2Al2Si3O10, and the secondary crystalline phasevaries from βⅡ′- Li2ZnSiO4 to γ0 - Li2ZnSiO4. Additionally, thermal expansion coefficient varies from 40.2 × 10^-7/K to 123.6 ×10 ^-7/K. And the thermal expansion coefficient 49.5 ×10^ -7/K was obtained by heat treatment at 535℃ for 2h and 700℃ for 2h, which can meet the requirements of sealing with 4J 29 Kovar alloy.
出处
《玻璃与搪瓷》
CAS
2009年第5期1-5,共5页
Glass & Enamel
