Structure of Bi_2O_3-ZnO-B_2O_3 system low-melting sealing glass

Bi2O3-ZnO-B2O3 system glass is a kind of lead-free low melting sealing glasses. The structure of Bi2O3-ZnO-B2O3 system low-melting sealing glass was investigated by DSC, FT-IR, XRD and SEM. The results show that with the increase of B2O3 content, the transition temperature Tg and softening temperature Tf of Bi2O3-ZnO-B2O3 system low-melting sealing glasses increase, which leads to the liquid phase precipitation temperature increasing and promotes the structure stability in the glass. With increasing the heat treatment temperature, a large number of liquid phases appear in samples and the sinter efficiency of the samples increases. The FT-IR spectra of the glasses show the presence of some bands that are assigned to vibrations of Bi--O bond from [BO3] pyramidal and [BiO6] octahedral units and B--O from [BO3] and [BO4] units. With the decrease of B203 content, the crystallization tendency of the glass increases. In glass samples Bl and B〉 crystallization starts at 460 ℃ and 540 ℃, respectively. Both of them precipitate Bi24B2O39 phases.

Effect of SrO Content on Structure,Thermal Properties and Chemical Stability of Bi2O3-B2O3-ZnO-SrO Low-melting Glass for Si-Al Alloy Package

The 40Bi2O3-30B2O3-(30-x)ZnO-xSrO (x=0-15mol%,BBZSr) glass system was prepared by the conventional melt quenching method.The effect of SrO addition on structure,thermal properties,chemical stability and sealing performance of BBZSr glass were investigated thoroughly.The experimental results show that the total proportions of [BO3] group and [BO4] group decrease and the vibrations of [BiO3] group and [BiO6] group become weaker with the increase of SrO addition content,suggesting the glass network structure is strengthened owing to the SrO addition.Hence,both the thermal and chemical stability were significantly improved as the SrO content was increased.When the SrO content increased from 0 to 15mol%,the glass transition temperature and softening temperature slightly increased from 380 to 388 ℃ and from 392.7 to 402.2 ℃,respectively,meanwhile the coefficient of thermal expansion also increased from 10.49×10^-6 to 11.16×10^-6/℃ (30-300 ℃).The BBZSr glass with 15mol% SrO exhibited excellent comprehensive properties with low glass transition temperature(384.9 ℃),low softening temperature(400.3 ℃),high coefficient of thermal expansion (11.14×10^-6 ℃,30-300 ℃),good thermal and chemical stability.Besides,the glass had the good wetting behavior and sealing performance for Al-50%Si alloy.

Preparation and Characterization of Low-melting Glasses Used as Binder for Protective Coating of Steel Slab

The low-melting phosphate glass was prepared for production of glass binders for protective coating of steel slab. Effects of different O/P ratios on glass structures and properties were analyzed. Differential thermal analysis （DTA） and infrared spectroscopy （IR） techniques were applied for low-melting glass binder. It was found that the glass transition temperature（T） was about 300 ℃ and softening temperature（T1） was about 480 ℃. The choice of O/P ratio was very important to the glass transition and softening temperatures. When more P=O bonds existed in the glass networks, P-O-P bond angle was deformed with decreasing of the ratio of O/E The coatings could adhere to the substrates instantaneously at 800 ℃ when the content of binder exceeded 3wt%. The optimal content of glass binder was 5wt%.

Dynamic performance of cable net facade with consideration of glass panels under earthquake

Shaking table tests and theoretical analysis were conducted to study the dynamic performance of cable net facade with consideration of glass panels under earthquake. Firstly,the dynamic response of cable net faade under earthquake was investigated with shaking table test. Then the working mechanism of glass panels in coordination with cable net was proposed. Accordingly,a numerical simulation model of glass panel's working in coordination with cable net was built for the dynamic analysis.And then the seismic response was analyzed with this model theoretically. The study indicates that the seismic response of the cable net with glass panels on most occasions is mainly decided by the symmetric modes,and the first vibration mode is dominant. The damping of cable net facade is mainly decided by glass panels. And it is very good for cable net faade to restrain its dynamic response under earthquake.

Purification effects of glass flux on A356 melt

In order to remove hydrogen and inclusions from A356 alloy melt, a low melting point glass flux, JDN Ⅱ, was developed. The results indicated that JDN Ⅱ flux has distinct effect of purification and protection on A356 alloy melt. When the dosage of the flux was 3%, the content of hydrogen in A356 melt was only 2.6?mL/kg at 857?℃ and 0.7?mL/kg even at 750?℃. In the meantime, the mechanical properties of the alloy increase greatly with the covering of 3% JDN Ⅱ flux. Compared with no flux, the tensile strength of A356 alloy increases by 9.42% and the elongation increases by 22%. The purification mechanism of JDN Ⅱ glass flux was discussed too.

高反射釉料对不同厚度光伏玻璃断裂强度的影响

高反射釉料常被涂覆在光伏玻璃上以提升其光电转化效率,然而,高反射釉料对光伏玻璃断裂强度的影响尚不明确。本文采用双环测试和四点弯曲测试定量研究了玻璃厚度(1.55、1.86和2.89 mm)、釉料种类(A和B)、加载速率(2、20、50 mm/min)及上压头受力面(釉料面、玻璃面)等对光伏玻璃断裂强度的影响,并结合Weibull分布分析变量对光伏玻璃断裂强度的影响。研究结果表明,两种高反射釉料都能显著降低光伏玻璃的断裂强度,其中,在釉料面朝下时,双环测试的断裂强度降低超过72%,远超过四点弯曲强度的降低幅度(26%~46%)。此外,随着玻璃厚度的下降,断裂强度显著降低,例如,四点弯曲测试中,2.89 mm厚度带釉料的全钢化光伏玻璃断裂强度为104 MPa,而1.55和1.86 mm厚度半钢化光伏玻璃的断裂强度仅为68和73 MPa。通过扫描电子显微镜发现,釉料层与光伏玻璃基体中的微孔等缺陷是导致光伏玻璃断裂强度下降的主要原因。

两点弯曲下柔性玻璃变形和疲劳行为研究

基于两点弯曲法加载方式及原理,分析了柔性玻璃的弯曲变形及疲劳行为,推导了弯曲曲率半径、弯曲应力与板间距之间的定量关系,基于高周疲劳理论,建立了柔性玻璃的应力-寿命(S-N_f)模型。结果表明,两点弯曲作用下,柔性玻璃试样的厚度不会改变其弯曲挠曲线轨迹,通过调节板间距,可获得试验所需的试样弯曲曲率半径。忽略柔性玻璃厚度的影响,试样的弯曲曲率半径与板间距呈线性关系,弯曲最大拉应力与弯曲曲率半径成反比。选择的最小弯曲曲率半径R_(min)越大,试样疲劳寿命越高,最大弯曲曲率半径R_(max)值的增大并不会显著影响试样的弯曲疲劳次数。Basquin模型能够有效预测不同交变应力或不同弯曲曲率半径作用下柔性玻璃的弯曲疲劳寿命。

玻璃粉对陶瓷化PVC复合材料性能影响

探讨了玻璃粉用量对陶瓷化聚氯乙烯(PVC)复合材料性能的影响。结果表明,添加60份自制玻璃粉,PVC复合材料综合性能较好,材料硬度(邵氏D)可达41,氧指数达到30%。随着玻璃粉含量增大,复合材料内部孔洞变多自支撑力改变,在600℃烧蚀30 min后所形成的陶瓷体成瓷效果好,结构密实且强度高、自支撑能力强、内部孔洞少、瓷化作用明显。

The morphology and dynamic viscoelasticity for PPS/low-melting temperature glass hybrids prepared by melt blending

Polyphenylene sulfides（PPS） and low-melting temperature glasses（LMTG） were used to prepare a PPS/LMTG organicinorganic hybrid material by melt blending.The etched surfaces of the hybrids were observed by scanning electron microscope （SEM） and the images showed different dispersed phase morphologies compared to traditional filled composites,which maybe induced by shear.Advanced rheometric expanded system（ARES） was used to investigate the rheological behaviors of the hybrids and the results showed that the strain y dependence of dynamic storage modulus G＇ for the hybrids with high contents of LMTG did not appear Payne effect.

改进型点支玻璃幕墙在建筑装饰工程中的应用研究

玻璃幕墙将墙与窗融为一体,可体现建筑围护的装饰、应用功能,增强建筑的现代感。玻璃幕墙的质量轻,不会增加建筑承载,且采光率高、结构简单、维修便捷,这些特点使玻璃幕墙广受关注。点支式玻璃幕墙具有通透性极高,支承结构简洁明快,施工安装简便,防尘防水隔音效果好,安全性好,耐久性强等众多优点,得到了广泛的应用。本文以某建筑装饰工程作为研究对象,采用案例分析法,着重分析改进型点支式玻璃幕墙的施工工艺流程及应用效果,以期为同类型项目提供参考。

CuO掺量对ZnO-B_(2)O_(3)-Bi_(2)O_(3)玻璃结构与热性能的影响

为了降低硼酸盐无铅封接玻璃的软化温度,研究了CuO掺量(0~15%,质量分数,下同)对40ZnO-30B_(2)O_(3)-30Bi_(2)O_(3)玻璃结构及热性能的影响。结果表明,在950℃保温2 h的熔制工艺条件下,试验组成范围内均能形成均质玻璃。随着CuO掺量增加,ZnO-B_(2)O_(3)-Bi_(2)O_(3)玻璃中的[BO_(3)]/[BO_(4)]结构单元比例先增大后减小,在CuO掺量为8%时达到最大值,此时[BO_(3)]结构单元含量相对较多。当CuO掺量进一步增加,部分[BO_(3)]逐渐向[BO_(4)]转变。此外,随CuO掺量增加,玻璃化转变温度及析晶温度逐渐降低,在400~850℃范围质量损失速率逐渐减小,但15%高掺量时呈现质量增加的趋势。玻璃的平均线热膨胀系数(25~450℃)随CuO增多无明显变化,保持在7.10×10^(-6)℃^(-1)左右。玻璃的软化温度和半球温度呈先降低后升高的趋势,当CuO掺量为8%时,软化温度和半球温度最低。

硫系玻璃单点金刚石车削技术的研究进展

硫系玻璃是应用较为广泛且较难加工的红外光学元件。单点金刚石车削加工技术不仅具有较高的加工质量,还能有效避免磨料嵌入光学元件导致面形精度降低,适用于小口径、大批量硫系玻璃镜片的超精密加工。本文介绍了硫系玻璃单点金刚石车削加工的原理和条件,综述了硫系玻璃单点金刚石车削加工过程中机床、刀具、加工工艺等对面形精度和表面光洁度的影响。

高层住宅建筑点支式玻璃幕墙施工方法

点支式玻璃幕墙取消了横梁与立柱,虽然具有更好的通透性和视觉效果,但其施工工艺却更加复杂且施工难度更大。本文研究的高层住宅建筑中点支式玻璃幕墙的施工方法,旨在提高幕墙施工的质量与效率,确保建筑的安全性。通过对现有施工技术的梳理与分析,提出一种优化后的点支式玻璃幕墙施工方法,阐述了其施工步骤和关键技术要点,该方法主要包括准备工作、测量与定位、支撑结构安装、玻璃板安装、密封处理以及质量检查与验收等步骤。最后,还强调了施工中的安全与环保措施,提出提高施工效率和质量的建议,研究成果对于指导高层住宅建筑点支式玻璃幕墙的施工实践具有一定理论指导和应用价值。

Na_(2)O含量对钠铝硅盐玻璃的化学强化性能及软化点的影响

采用溢流下拉法制备了不同Na_(2)O含量钠铝硅酸盐玻璃,采用一步强化法对样品进行化学强化,探究了Na_(2)O含量对铝硅酸盐玻璃的特征温度点及化学强化特征参数的影响。结果表明:对于化学强化过程,随着组分中Na_(2)O含量的增加试样的离子交换深度随之增加;且适当提高强化温度、延长强化时长可促进Na^(+)—K^(+)交换,在强化温度为415℃,强化时长为330 min时,试样抗弯曲强度和抗冲击强度分别为774 MPa和0.34 J。随玻璃组分中Na_(2)O含量的增加,玻璃网络结构中出现非桥氧数增加,使玻璃NLS的软化点温度随组分中Na_(2)O含量的增加而减小。

热膨胀法测定玻璃热性能的应用评估

热膨胀法可以测定玻璃的热性能,包括:热膨胀系数α与应变点T_(st)、转变点T_(g)、退火点T_(a)、膨胀软化点T_(d)等特征温度点。对热膨胀法测定玻璃热性能的应用进行评估,评估结果表明:(1)玻璃的热膨胀系数α会随着温度段变化而变化,同时在一定范围内,升温速率越大,热膨胀系数越小;(2)热膨胀法测定玻璃特征温度点的重复性偏差在±10℃以内,一定范围内,升温速率越大,特征温度点温度越高;(3)热膨胀法测定玻璃热性能的升温速率优选3℃/min;(4)玻璃中B_(2)O_(3)含量越高,同时CaO含量越低,那么玻璃的热膨胀系数α越小,玻璃的应变点T_(st)与转变温度T_(g)越小,退火加工温度范围也就越大。

不同铺层结构GLARE层板弯曲失效机理的声发射研究

玻璃纤维增强铝合金(Glass Fiber Reinforced Aluminum,GLARE)层板是一种在航空工业中被广泛使用的混杂复合材料。本研究采用三点弯曲试验方法对其进行弯曲加载,同时利用声发射技术(Acoustics Emission,AE)对弯曲过程中层板的损伤行为进行实时监测,并基于多AE参数及K-means聚类方法探究了不同铺层结构GLARE层板的弯曲性能及失效机理。结果表明:铝合金的铺层位置对GLARE层板的弯曲性能有显著影响;最外层铝合金与复合材料层的变形协调作用可以有效延缓损伤的起始与演化。GLARE层板在弯曲失效过程中的损伤模式及对应的峰值频率为:0~50 kHz代表铝合金损伤,80~210 kHz代表基体开裂,210~320 kHz代表纤维剥离和界面分层,320~400 kHz代表纤维断裂。

玻璃幕墙施工技术要点及现场管理分析

玻璃幕墙施工技术与传统墙面技术相比,不仅外观形象更好,同时具有良好保温性以及防风性,对提升建筑物质量产生了重要影响。由于玻璃幕墙施工主要材料以玻璃为主,因此整体施工难度较大,需要加强技术工艺以及现场管理,提高施工效率以及施工水平。基于此本文结合工程案例,对玻璃幕墙施工技术要点以及现场管理步骤进行分析研究。

建筑工程中玻璃幕墙施工技术要点分析

在我国社会科技不断发展的过程中,幕墙被投入到广泛的应用中。对于幕墙工程来说,玻璃幕墙是一个核心要素,无论从施工准备环节,还是最后的竣收环节,都会影响工程质量。下文对玻璃幕墙施工安装过程要点进行讨论,以期为同行工作者们带来参考。