真空玻璃的支撑与封接技术研究进展

真空玻璃具有优异的隔热、隔声性能,广泛应用于建筑物和人们的生产生活,是一种新型的建筑节能玻璃.本文介绍了钢化、合金、非金属、吸附类、非金属类填充型支撑柱及真空玻璃边缘激光、含密封帽式、金属氧化物封接料等封接技术的发展,综述了国内外真空玻璃的制备工艺和研究进展.针对支撑柱耐久性差、易脱落、导热性较强及玻璃封接过程中密封性...     

真空玻璃封接接头残余应力的影响因素分析

采用正交设计和有限元模拟的方法研究了真空玻璃的钎焊温度、保温时间、钎料厚度和施加压力等工艺参数对真空玻璃封接接头残余应力的影响,并分析不同钎焊工艺对真空玻璃封接接头剪切强度的影响,确定了最优水平组合。结果表明:钎料的厚度对接头残余应力的影响最为显著,施加压力对接头残余应力的影响较为显著,钎焊温度和保温时间的影响较小;钎焊温度为275℃,保温时间为20 min时,接头剪切强度最高。最优的水平组合为钎焊温度275℃,保温时间20 min,钎料厚度为0.3 mm,施加压力为8.56 N。优化的参数设计能够减小接头的残余应力,有利于提高接头的强度。     

真空玻璃支撑压痕控制准则

为避免过大的支撑物支撑应力导致真空玻璃基片赫兹裂纹的产生,首先建立了力学模型,分析了支撑物接触部位玻璃的应力分布特征.应用Griffith断裂理论和均强度理论,分别得到了玻璃基片在不产生压痕下支撑物的最大临界支撑力计算公式.通过与试验结果进行比较,发现两种理论计算结果均与试验结果相吻合,,但断裂力学理论得到的支撑物临界支撑力比试验结果偏小,而均强度准则结果偏大.对真空玻璃结构设计,在已知的真空玻璃材料参数下,根据上述理论,计算出玻璃基片不产生压痕下支撑物的最大临界支撑力,从而确定支撑物最佳排列间距,使真空玻璃达到"热学与力学"最佳配制.     

He-Ne激光陀螺仪真空铟封结构应力分析与工艺优化

氦氖激光陀螺仪电极封接是维持其微晶玻璃谐振腔体真空环境的关键技术之一。研究分析了氦氖激光陀螺仪经典铟封接结构特点及电极铟封性能,应用弹塑性力学理论建立铟封结构的物理和数学模型。数值计算了铟封结构残余应力,得到了不同物性参数的残余应力变化规律,分析了铟丝环直径、铟合金化学计量比等参数对铟封残余应力的影响;优化了封接工艺参数,提高了封接强度及谐振腔真空铟封性能,使铟封接强度与真空气密性能满足氦氖激光陀螺仪长寿命的使用要求。     

不锈钢真空容器无尾封接生产用玻璃粉的研究

Pb-B-Si系低熔点玻璃是一种具有较好封接性能的玻璃粉,将其应用在不锈钢真空保温容器无尾封接中存在真空烧结时气泡消除缓慢、强度不够等问题。通过对Pb-B-Si系玻璃进行配方优化调节后,对玻璃粉进行性能检测,对焊点形貌等进行研究,采用扫描电镜分析了烧结层的微观结构。结果表明,优化后的配方体系为Pb-B-Si-ZnAl-CuO,其中Pb为83%,CuO为3.5%(质量分数)时,可以显著提高无尾封接时的强度,提高真空度。使用该玻璃粉生产的不锈钢真空容器的焊点饱满、光亮,接头强度好,无明显缺陷,显示其对不锈钢容器良好的封接强度。     

第15讲真空工程封接技术

真空封接属于真空连接技术中的永久性连接,真空封接技术常用于某些真空室、真空炉体、真空泵体、真空规的各种电极、引线等零部件的金属材料与玻璃、陶瓷等非金属材料之间的密封连接以及非金属材料之间的密封连接。真空封接连接应满足以下要求:1真空密封;2耐高温(真空系统烘烤、电极加热、引线发热等);3电绝缘性能。1玻璃-玻璃封接在真空技术中有时会用到玻璃与玻璃、石英与石英的封接工艺。在设计和制造玻璃真空系统时,需要考虑系统的玻璃管道封接、管道与真空零件的封接。同种和不同种玻璃材料之间靠熔融过程实现封接,温度应升高到超过玻…     

中温固体氧化物燃料电池封接玻璃的研究进展

封接玻璃是中温固体氧化物燃料电池(IT-SOFC)的主要组成部分, 封接玻璃应同时具有适宜的热性能、化学性能、力学性能及与电池元件有良好的粘合能力, 防止SOFC在运行过程中气体的泄漏, 并保证玻璃在IT-SOFC工作温度及氧化气氛或燃料气氛下长期运行的热稳定性和封接玻璃与其它电池元件之间的界面稳定性。本文综述了关于IT-SOFC封接玻璃近十年的研究进展。从玻璃特性和封接玻璃与元件之间的界面反应的角度, 讨论封接玻璃的组分-结构-性能三者之间的关系, 提出了当前IT-SOFC封接玻璃研究的主要问题。     

基于玻璃浆料键合的硅基漏孔封接工艺优化研究北大核心CSCD

随着漏孔在超高真空计量应用的广泛需求,目前常用的Torr-Seal胶封接方法由于其高放气率而不再适用,迫切需要一种放气率低、气密性好的封接方法。本文提出了一种新的基于玻璃浆料键合的硅基漏孔封接方法,即利用玻璃浆料键合工艺将硅片封接到可伐管上,并通过法兰连接到真空测试系统中。研究优化了玻璃浆料的热调节工艺,并使用氦质谱检漏仪测量了封接组件的本底漏率。测量结果显示,在一个大气压的上游压力下测得的最小本底漏率为1.0×10-13 Pa·m3/s。采用仿真软件ANSYS对封接的降温阶段进行了热应力分析,根据仿真结果证明了可伐合金的优越性。     

低熔封接玻璃的研究进展

低熔封接玻璃是一种先进的焊接材料,由于其具有低的熔化温度和封接温度,优良的机械强度和化学稳定性,而在很多领域中得到广泛的应用,实现了玻璃、陶瓷、金属、半导体间的相互封接.综述了低熔封接玻璃的研究现状,展望了低熔封接玻璃向无铅化发展的趋势,指出了无铅低熔封接玻璃今后的研究方向.     

固体氧化物燃料电池封接玻璃的研究:成分与性能

固体氧化物燃料电池封接玻璃在初期必须具备一定的流动性以便有效形成封接,进而保持足够的机械强度。它的热膨胀系数必须与燃料电池的其它部件相匹配,还需要具有化学稳定性。通过对研制的80多个逆性硅酸盐玻璃成分的分析,获得了成分-性能的一些规律:B2O3能够降低玻璃的软化温度和玻璃转变温度;ZnO通过拓宽玻璃转变温度和结晶温度之间的温度范围而改善封接性能,如Zn/Si比为0.7的成分可以获得230℃的温度范围;逆性玻璃的热膨胀系数取决于网络配体的平均势场强度,如加入BaO因为其较小的势场强度而提高玻璃的热膨胀系数,而加入势场强度较大的ZnO则呈现相反趋势。     

Vacuum glazing: Current performance and future prospects

The development of vacuum glazing is a significant advance in the area of low heat loss glazing systems with great potential to reduce building heating and when combined with solar control glazing, cooling loads. The basic concept of vacuum glazing is reviewed and the procedures and research undertaken in the development of both high-temperature and low-temperature sealing of vacuum glazing are outlined. The achieved thermal performance of current laboratory systems and those that are now commercially available are presented. The potential levels of performance that may be achieved using high-performance low-emittance (low-e) coatings and tempered glass are reported. Research into window systems that incorporate vacuum glazing to achieve improved thermal performance is also outlined.     

The thermal performance of an electrochromic vacuum glazing with selected low-emittance coatings

An electrochromic (EC) vacuum glazing (VG) is formed when a vacuum glazing is combined with an electrochromic glazing. Three glass panes are required, two of which may have a low-emittance coating separated by a pillar array, the space formed being evacuated and sealed contiguously by a metal edge seal, the third glass pane with an EC layer is sealed to the evacuated glass unit. With the EC glazing installed with the electrochromic component facing the outdoor environment, for an incident solar radiation of 300 W m^− 2, when the EC layer is opaque for winter conditions, the inside glass pane of the unit due to solar radiation absorbed by the low-emittance coatings within the vacuum gap and electrochromic layer is a heat source with heat transferred from the glazing to the interior environment.     

大厚度差真空玻璃隔声特性研究

Cabrera和Nugroho等人对3v3(3 mm单层玻璃+0.2 mm真空层+3 mm单层玻璃)、3v5以及5v5构造的真空玻璃进行了研究,结果表明真空玻璃的隔声特性符合薄板隔声理论,但10 mm单层玻璃较符合厚板隔声理论。因此需进一步研究当真空玻璃的厚度进一步增大后的隔声特性。文章增加真空玻璃厚度至3v10,采用现场声强测量法进行隔声测量,基于Davy和Sharp隔声理论建立了隔声模拟模型,对实测和模拟特性进行对比分析。结果表明,3v10真空玻璃的隔声特性更符合厚板隔声理论。与3v5真空玻璃相比,3v10真空玻璃的计权修正表观隔声量未明显提高,但有助于降低现场隔声等级隔声最低值与评价量之间的差值。     

Evacuated aerogel glazings

This paper describes the main characteristics of monolithic silica aerogel and its application in evacuated superinsulating aerogel glazing including the evacuation and assembling process. Furthermore, the energetic benefit of aerogel glazing is quantified. In evacuated aerogel glazing the space between the glass panes is filled with monolithic silica aerogel evacuated to a rough vacuum of approximately 1-10 hPa. The aerogel glazing does not depend on use of low emissive coatings that have the drawback of absorbing a relatively large part of the solar radiation that otherwise could reduce the space heating demand in residential buildings. The U-value of the glazing can be designed to meet the required value by increasing the monolithic silica aerogel thickness without the need for additional layers of glass. An aerogel glazing with 20 mm glass distance can reach a U-value below 0.5 W/(m² K) combined with a solar energy transmittance above 0.75.     

真空平板玻璃支撑应力实验研究

用弹性力学的结点法建立真空玻璃支撑应力-应变力学模型，求出真空玻璃的支撑应力-应变场，分析了其应力-应变分布规律，同时用了电测方法进行试验验证。试验结果表明，真空玻璃最大应力发生在四角第二个支撑处，最大应力弹性力学计算值11．057MPa，电测法的测试值11．765MPa，两者误差为6．02％。支柱横截面上的正应力为179MPa，纵向变形为0．2686μm（钢柱），0．7414μm（玻璃柱）。控制支撑高度误差和玻璃的平整度，保证受力的均匀，可增加真空玻璃的强度，增加其可靠性，提高其使用寿命。     

Verbesserung des Vakuums in Isoliergefäßen aus Glas

Improving the vacuum would increase the insulation capacity of commercially available glass containers by a factor of about two. To do this, pressures of 10^?4 mbar must be attained. Different approaches were taken to meet this objective. As an alternative to today's commonly practiced sealing method, three possibilities are introduced which eliminate the necessity of pump stub narrowing which causes reduced conductance. Furthermore, depending on the sealing process used, the gases occuring during sealing are either avoided completly or they can at least be reduced by having the chance of exact temperature control resp. by a lower separation temperature. A completly different approach was taken by using Getters, of which a metal hydride on a TiVMn base proved especially suitable. It is activated by heat and can be integrated into the normal production process without any problem. Aside from a shorter pump period, the added advantage here is the containment of the gasses occuring during sealing as well as that of the longterm gasses.     

Preparation of a transparent supporting spacer array for vacuum glazing

Materials used to produce spacers present in vacuum glazing have classically been opaque. The present study suggests a method to produce transparent spacers, which allows for the production of novel nearly transparent vacuum glazing. The transparent glass spacer array between two sheets of glass substrates was prepared by screen printing. A typical paste composition with suitable screen-printing behaviors is evaluated in weight percent: 24 Wt% organic vehicle, and 76 Wt% low melting glass powder. The paste is a shear thinning and has a viscous liquid behavior dispersion system with little thixotropy. This novel method to prepare a transparent spacer array for vacuum glazing is reliable and superior to the commonly used metal pillar array in terms of appearance, transmittance, Vickers hardness, and the thickness uniformity of the prepared spacers.     

Failure probability of laminated architectural glazing due to combined loading of wind and debris impact

Building façades are vulnerable to wind and wind-borne debris during extreme weather conditions like hurricanes. Laminated glazing is widely used as window glazing material to ensure the integrity of the building interiors. Wind-borne debris has been classified as small-hard and large soft missiles representing small gravel to large wooden bars that constitute the debris impacting the glazing during severe storms. Failure of laminated window glazing due to combined effect of wind and debris is studied. Stress analysis is done using finite element code ABAQUS. This is used in conjunction with a mechanics based statistical model to predict the cumulative probability of inner glass ply breakage in laminated glazing. A parametric study involving failure probability of inner glass ply for different geometry of laminated glazing is also performed.     

钠燃烧试验厂房隔热密封门的设计与分析

钠燃烧过程会造成试验厂房内的温度和压力显著升高.试验厂房的门作为厂房边界的一部分,应具备防火隔热和承压密封的功能,但在目前的实际应用中并没有可以满足该要求的工程门.基于此,针对钠燃烧过程的特点,并结合核工程的实际工况,设计了一种兼具防火隔热和承压密封功能的新型隔热密封门.以核工程中不同工况下常用工程门的结构为基础,结合...     

光学玻璃精密模压成形设备密封设计

目的研究高温情况下光学玻璃精密成形设备加热系统的密封性能。方法通过数值模拟分析,得到加热系统的温度场分布以及密封圈的温度变化规律,利用热电偶及红外测温仪对加热系统加热性能及安全性进行检测,在此基础上,对加热系统进行改进。结果随着加热时间和功率的增加,密封圈的温度随之上升。模压温度过高,橡胶圈存在破坏的可能。结论通过对密封处进行改良,橡胶圈在安全工作范围内,加热效率得到了改善。在机械泵和分子泵的共同作用下,模压腔内的真空度达到1 Pa以下。