【作者】 陆平；

【导师】 程金树；

【作者基本信息】 武汉理工大学 ， 材料学， 2008， 博士

【摘要】 随着电子、生物、安全、新能源和航空航天等领域的发展,对相关平板玻璃材料提出了更高的要求。硼硅酸盐玻璃具有非常优异的性能,如良好的热稳定性、化学稳定性、机械性能、可加工性能和光学性能等,能满足这些要求。同时,用浮法工艺生产平板玻璃具有许多众所周知的优点,如成本低、产量大、表面质量好和品种多等,是大规模生产平板玻璃的最佳工艺。采用浮法工艺生产平板玻璃,锡槽段的成形工艺及原理是其关键技术之一。本课题采用高温粘度仪、高温表面张力仪、电子探针、原子力显微镜等现代分析测试手段,主要开展硼硅酸盐浮法玻璃成形工艺和原理的研究。主要工作和得到的结论如下:1、研究了硼硅酸盐浮法玻璃在锡液上的摊平过程,测试了玻璃的高温粘度,高温表面张力和高温密度,比较了硼硅酸盐浮法玻璃和钠钙硅浮法玻璃成形工艺的异同。研究表明:（1）平衡厚度:硼硅酸盐浮法玻璃的平衡厚度大于钠钙硅浮法玻璃的平衡厚度,并随着温度的升高而降低,1170℃约为7.46mm,1270℃约为7.10mm。对于硼硅酸盐浮法玻璃而言平衡厚度（T_h）和温度（T）的关系满足经验公式T_h=12.25-0.00408 T（1170℃＜T＜1270℃）。引入表面张力和密度的测试结果,将该公式进行理论化延深,还可以通过高温时玻璃表面张力/密度比值（Φ）来判断平衡厚度（T_h）。它们之间的关系满足T_h=0.060Φ-2.423。（2）抛光过程:高温表面张力/粘度比值是决定抛光效果和平整化时间的关键,现有浮法成形理论中抛光和平整化过程没有明确界限。本文认为抛光过程体现了高温时表面张力/粘度比值的微观效应,而平整化过程体现了高温时表面张力/粘度比值的宏观效应。浮法玻璃高温抛光过程中时间不是限制玻璃表面抛光质量的决定因素,温度是决定抛光质量的关键。硼硅酸盐浮法玻璃在大于1230℃以上的温度可以达到良好的抛光效果。（3）平整化过程:硼硅酸盐浮法玻璃平整化时间随着温度的升高而缩短,1168.6℃时大约需要109s,1276.7℃时大约需要35s。提出以表面张力与粘度在1168.6～1276.7℃范围的比值（88～97）,并结合抛光需要的温度（＞1230.0℃）共同决定硼硅酸盐浮法玻璃摊平抛光区域范围的方法。结合粘度曲线,制定出了硼硅酸盐浮法玻璃锡槽各区域的温度制度。2、模拟浮法玻璃的成形过程,探索了时间、温度和保护气体纯度对锡离子渗透的影响,比较了相同实验条件下钠钙硅浮法玻璃和硼硅酸盐浮法玻璃的渗锡特点。最后通过对渗锡量不同的硼硅酸盐浮法玻璃进行热处理,说明了产生热加工虹彩的渗锡量临界值。研究表明:（1）硼硅酸盐浮法玻璃涉锡面锡离子渗透深度可达25～40μm,渗锡量为0.2～1.2 at%。随着玻璃在锡液上停留时间的延长渗锡量增多,高温时锡离子以纵深方向的扩散为主,低温时在表面7μm左右以下的表层聚集。由于温度引起的硼反常现象,硼硅酸盐浮法玻璃在1050℃时产生异常凸起的渗锡曲线,但在较低的温度下会由于锡离子的逆扩散而消失。（2）相同条件下硼硅酸盐浮法玻璃的渗锡量小于钠钙硅浮法玻璃的渗锡量。（3）硼硅酸盐浮法玻璃产生热加工虹彩的临界渗锡量为0.81at%左右,提高保护气体的纯度有利于减少渗锡量。3、渗锡可以改变玻璃的表面性质,本文研究了硼硅酸盐浮法玻璃在生产过程中可能产生的相变情况,探明了锡离子渗透对硼硅酸盐浮法玻璃析晶的影响。研究表明:（1）硼硅酸盐玻璃表面在750℃保温20min左右会析出SiO₂晶体。（2）渗入硼硅酸盐浮法玻璃涉锡面的锡离子可以抑制其表面析晶的程度。更多还原

【Abstract】 With the developing of electronics,biotechnology,security,new energy and aerospace fields,they have a higher demand to related flat glass.Borosilicate glass has a very high-performance,such as good thermal stability,chemical stability, mechanical properties,machine performance and optical properties,to meet these requirements.At the same time,flat glass producted by the float process have many well-known advantages,such as low cost,production,good surface quality and more variety,is the best technology for large-scale production of flat glass.And for a float flat glass production process,the forming process and the principle of the tin bath is one of its key technologies.In this study,high temperature viscosity,surface tension,electronic probe, atomic force microscope and other modern means of testing were used,mainly in borosilicate float glass forming process and the principle.The main work and conclusions are as follows:1.The flatting and polishing process were studied.The viscosity,the surface tension and the density of borosilicate glass at high temperature were measured,and differences between borosilicate float glass and sodium-calcium-silicon float glass were compared.The results show that:（1）Equilibrium thickness:The equilibrium thickness of borosilicate float glass is greater than that of sodium calcium silicon float glass.It is decreasing with temperature,about 7.46 mm at 1170℃,and about 7.10 mm at 1270℃.For borosilicate float glass,equilibrium thickness（T_h）and temperature（T）meet the empirical formula relationship:T₌12.25-0.00408 T（1170℃＜T＜1270℃）. Introducing the ratio of surface tension to density of the test results,the theory of the formula can be extended.The equilibrium thickness（T_h）of borosilicate float glass can be judged through surface tension/density ratio（Φ）of glass.The relationship between them meet T_h=0.060Φ-2.423.（2）Polishing process:The polishing effect and flatting time were both determined by surface tension/viscosity ratio at high temperature.But there is no clear boundaries between them in the existing float forming theory.This article holds that the polishing process reflects the microcosmic effect of the surface tension/viscosity ratio,and the flatting process reflects the macroscopical effect of the surface tension/viscosity ratio.The surface quality of float glass in polishing process is not restricted by time,but by temperature.Borosilicate float glass can reach a good polishing quality at the temperature above 1230℃.（3）Flatting process:The flatting time of borosilicate float glass is shortening with the increase of temperature,about 109s at 1168.6℃and 35s at 1276.7℃.A new method is put forward to choose the polishing and flatting region of borosilicate float glass,i.e.combining surface tension/viscosity ratio（88～97）from 1168.6 to 1276.7℃and the needed temperature（＞1230.0℃）for polishing decided jointly. The tin bath regional temperatures of the borosilicate float glass were compartmentalized by this new method and supplemented by the viscosity curve.2.The effects of time,temperature and protection gas on penetration of tin into borosilicate float glass were studied by simulating the actual forming process of float glass.The similarities and differences between borosilicate float glass and sodium calcium silicon float glass were compared under the same experimental conditions. Finally,the borosilicate float glasses including different concentration tin were heated to demonstrate the critical value of tin concentration which bring on bloom.The results show that:（1）The tin ion penetration depth is about 25 to 40μm in borosilicate glass float, and tin concentration is about of 0.2 to 1.2 at%.The amount of tin in borosilicate float glass increased with the residence time of glass on tin liquid extended.The tin ions mainly entered into deep layer at high temperature and congregated at surface layer（＜7μm）at low temperature.The anomaly boron phenomena caused by temperature can induce an abnormal tin penetration profile,but it would disappear at lower temperature because of inverted penetration.（2）The tin penetration amount of borosilicate float glass was less than that of sodium calcium silicate float glass under the same conditions.（3）The critical value of tin concentration which bring on bloom to borosilicate float glass was about 0.81 at.%,and increasing the purity of protection gas was propitious to decrease the amount of tin penetration.3.The penetration of tin into the surface can change the property of borosilicate float glass.The possible phase transition and the effect of tin on borosilicate glass were studied.The results show that:（1）The borosilicate glass surface may crystallize SiO₂ crystal at about 750℃.（2）The tin ions penetration into the surface of borosilicate float glass can inhibit the extent of surface crystallization,and will not bring more bad effects.更多还原