铜封微晶玻璃

铜封微晶玻璃与铜封玻璃相比具有机械强度高,化学稳定性好的优点,用铜封微晶玻璃与金属铜封接,可制成输送大电流的接插件或大功率的电子器件,可显著提高封接器件的坚固性、使用寿命和使用温度。国内研制成的铜封微晶玻璃的典型成份之一(7003~#)如下(重量％):     

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。     

IT-SOFC硼酸盐玻璃体系封接材料的制备与性能研究

基于B2O3-CaO-BaO-Al2O3-SiO2-La2O3体系制备了BCAS微晶玻璃封接材料,利用X射线衍射定性分析、差热分析、热膨胀仪分析等手段对其进行了表征.热膨胀系数(TEC)为10.41×10-6K-1,与电解质YSZ的热膨胀系数(10.2～10.8)×10-6K-1相接近.玻璃转变温度T8值为638℃,在768～852℃之间有一个强的放热峰.700℃时其主晶相为BaAl2 Si2 O8,800℃时以钡长石为析出的主晶相,900℃时析出单一的BaAl2Si2O8相及少量的BaSiO3相.封接材料的电阻随温度升高而减小,在650～800℃之间,阻抗值均在104～105Ω·cm2范围内,离子跃迁活化能为101.38 kJ/mol.其高温浸润性研究表明BCAS1微品玻璃封接材料可用于IT-SOFC对电解质YSZ的封接.     

固体氧化物燃料电池密封稳定性的研究进展

固体氧化物燃料电池(SOFCs)的密封质量直接影响其工作性能和寿命,是实现SOFCs商业化应用必须解决的课题之一.综述了玻璃/微晶玻璃封接、压缩封接和金属气密封接在耐久性和耐循环性方面的研究现状,从气密性、热失配补偿和化学稳定性方面分析了各方法的主要问题和解决办法,并展望了中低温SOFCs密封的发展方向.     

真空玻璃边缘封接强度及可靠性分析

用于真空玻璃边部封接的玻璃焊料不仅要满足真空密封性能,同时应满足封接强度要求。采用十字交叉法试验,获得了真空玻璃边缘封接部位界面拉伸与剪切强度,分析了真空玻璃服役过程中因玻璃自重、风载荷和温差作用而导致的真空玻璃边缘封接部位应力。通过试验验证和理论分析比较,结果表明:真空玻璃边缘封接部位强度能够承受因玻璃自重,温差,风压作用而产生的应力;在真空度失效的情况下,真空玻璃边缘封接强度足够高,依然可以承受3600Pa的风压作用,在应用过程中安全可靠。     

以钾长石制备α-堇青石微晶玻璃及其性能研究

以钾长石为主要原料,制备了α-堇青石微晶玻璃。采用差热分析(DSC)、X射线衍射仪(XRD)及场发射扫描电子显微镜(FESEM)分别研究了微晶玻璃的烧结和晶化行为、晶相组成及显微结构。探讨了晶化温度对微晶玻璃晶相、显微结构及性能的影响。结果表明,随着温度的升高,微晶玻璃中α-堇青石含量先增加后减小,而微晶玻璃孔隙先变少后增多;微晶玻璃抗折强度(最高达到131 MPa)高,介电常数(最低为4.56,200kHz)及介电损耗(最低为0.030,200kHz)低,晶化温度低于1000℃,可以用作低温共烧陶瓷材料。     

磁记忆存储器微晶玻璃基板

介绍了适用于高容量，小型化磁记录存储器基板的各种微晶玻璃材料，详细讨论了微晶玻璃的化学组成，显微结构，主晶相种类以及微晶玻璃的物化性能和表面特性，并与ＮｉＰ／Ａｌ基板材料性能进行了对比，简要介绍了硬盘微晶玻璃基板的实用性研究结果。     

填料对铋锌硼低熔封接玻璃膨胀系数的影响及其微结构研究

在匹配封接中,为确保材料和结构在冷热反复循环的稳定性和耐久性,需考察封接材料与基体材料的膨胀系数在工作温度范围内的匹配性,以使封接应力尽可能小。一般来说,低熔点玻璃封接温度越低,膨胀系数越大。为满足低温封接,同时膨胀系数小的实际需求,常常在低温封接玻璃粉中添加低膨胀耐火填料,制成复合型低温焊料。本文对比研究了堇青石、锆英石、β-锂霞石及锂铝硅(LAS)微晶玻璃4种填料对Bi₂O₃-ZnO-B₂O₃低熔封接玻璃膨胀系数的影响,并估算了各自的有效模量。结果表明:在添加量相同的情况下,堇青石填料调节作用最为显著;β-锂霞石、锂铝硅微晶玻璃虽然本身的线膨胀系数为负,但调节效果不理想,与堇青石相比略差;锆英石的有效模量值最大,但因其自身密度大,膨胀系数也大,调节效果不及另外3种填料。     

BaO-MnO-B2O3-SiO2密封玻璃与SS410连接极材料之间的化学相容性研究

制备了一系列BaO-MnO-B2O3-SiO2玻璃,通过DIL、XRD、SEM研究了其热膨胀行为、玻璃态转变、析晶行为及其与SS410金属连接极材料之间的反应。结果表明:所得密封玻璃的热膨胀系数约为10×10-6 K-1,与YSZ电解质材料和SS410金属连接极材料较为匹配,所得玻璃在800℃保温10h之后,生成了Ba5Si8O21相为主的微晶玻璃。玻璃的析晶对于密封玻璃与SS410连接极材料之间的化学相容性具有显著影响,析晶之后,玻璃与SS410之间的反应现象减弱。玻璃在N2气氛下进行预析晶处理,形成微晶玻璃之后,与SS410之间的反应显著减少。本研究所得的BaO-MnO-B2O3-SiO2密封玻璃在完成封接之后,在700℃保温100h,能够保持良好的密封效果。     

Li_2O-Al_2O_3-SiO_2微晶玻璃超光滑表面纳米硬度实验研究

介绍了纳米压痕技术的原理和方法.采用三角锥形Berkovich金刚石压头对Li2O-Al2O3-SiO2微晶玻璃的超光滑表面(Ra=0.079 nm)进行了纳米压痕实验.结果表明,当载荷低于300 mN时,微晶玻璃表现出延性特性.此外,在不同的载荷条件(20 mN~300 mN)下微晶玻璃的硬度和弹性模量存在较大的差异,分析其原因分别是纳米压痕的尺寸效应和材料发生了塑形变形.通过将实验得到的微晶玻璃的纳米硬度值与传统计算方法得到的硬度值进行比较,发现传统方法得到的硬度值较大,其原因是传统硬度计算方法忽略了材料的弹性恢复.     

Sol–gel based fabrication of novel glass-ceramics and composites for dental applications

The aim of this study is the fabrication of dental glass-ceramics able to elicit bioactive behaviour around the margins of fixed restorations and to provide a bioactive surface which can lead to periodontal tissue attachment, providing complete sealing of the marginal gap between tooth and fixed prosthesis. Sol–gel technique is applied for the fabrication of a new glass-ceramic in the system SiO₂60%–P₂O₅3%–Al₂O₃14%–CaO6%–Na₂O7%–K₂O10% (wt.%) and a related composite material combining this phase with the bioactive glass 58S. This composite material aims to create a bioactive surface which could lead to periodontal tissue attachment, providing complete sealing of the marginal gap between tooth and fixed prosthesis. The microstructural and thermal properties and the bioactive behaviour of the new materials were determined and were observed to be similar in respect to a commercial leucite based fluorapatite dental glass-ceramic. The feasibility of the new composite material to be applied as coating on the base porcelain as well as the bioactive behaviour of the fabricated coated specimes were confirmed.     

Crystallization and wetting of ZnO-Al2O3-B2O3-SiO2 glass-ceramic for sealing to Kovar alloy

A new type of ZnO-Al₂O₃-B₂O₃-SiO₂ glassceramics seals to Kovar in electronic packaging was developed, whose coefficient of thermal expansion (CTE) and electrical resistance were 5.2 × 10⁻⁶/°C and over 1 × 10¹³ Ω·cm, respectively. The major crystalline phases in the glass-ceramics seals were ZnAl₂O₄, ZnB₂O₄ and NaSiAl₂O₄. The dielectric resistance of the glass-ceramic could be remarkably enhanced through the control of the alkali metal ions into the crystal lattices. It was found that the crystallization happened first on the surface of the sample, leaving the amorphous phase in the inner parts, which makes the glass suitable for sealing. The glass-ceramic showed better wetting on the Kovar surface, and sealing atmosphere and temperature showed great effect on the wetting angle. Strong interfacial bonding was obtained, which was mainly attributed to the interfacial reaction between SiO₂ and FeO or Fe₃O₄. This paper was presented at 2008 MRS International Materials Research Conference and won the student best paper award of the conference.     

纤维涂层对复合材料力学性能的影响

对于ＳｉＣ纤维／ＭＡＳ微晶玻璃复合系统，发现在烧结温度下，纤维和基体之间有较严重的化学反应发生，界面结合强，力学性能较差．通过对ＮｉｃａｌｏｎＳｉＣ纤维加涂层，发现Ｎｂ２Ｏ５和ｃ涂层对复合材料的界面结合改善不大，而ＬＣＡＳ晶玻璃涂层能使纤维和基体间的界面结合明显减弱，力学性能大幅度提高，室温抗折强度和断裂韧性分别达３２７ＭＰａ和１３．９ＭＰａ·ｍ１／２．     

齿科微晶玻璃的腐蚀机理及溶胶-凝胶防腐蚀涂层研究

利用体外试验方法以及SEM／EDAX、ICP、FTIR等分析技术，对氟硅碱钙石(fluorcanasite,K2Na4Ca5Si12O30F4)齿科微晶玻璃的腐蚀机理，以及溶胶-凝胶Al2O3，、TiO2及ZrO2涂层改善微晶玻璃抗侵蚀的效果进行了比较分析．研究表明，口腔溶液对该齿科微晶玻璃的侵蚀源于溶液中的H3O 离子与微晶玻璃表面的Na 及K 发生迅速的离子交换，从而形成结构疏松的表面富SiO2层，其Si-O网络进而被H2O分子所断开，使SiO2以可溶性硅胶形式溶解于溶液中．此反应导致大量的表面结构缺陷，从而降低了材料的强度和使用寿命。浸泡25天后微晶玻璃表面最终的反应产物是一层低结晶度的颗粒状碳酸羟基磷灰石Cal0(PO4)6(2OH-，CO3^2-)．溶胶-凝胶A12O3涂层具有显著的改善齿科微晶玻璃抗唾液腐蚀的作用。     

锂离子玻璃及微晶玻璃固体电解质的发展及应用

综述了锂离子氧化物、硫化物玻璃及微晶玻璃固体电解质的研究进展.重点讨论了这些材料的电化学性能,以及离子掺杂对电化学性能的影响.探讨了锂离子玻璃和微晶玻璃固体电解质的发展及应用前景,认为其在全固态电池中的应用将随技术的发展实现商业化.     

Glass-ceramics with random and oriented microstructures

The technique of hot extruding a glass-ceramic to produce a material with an aligned crystal microstructure is described. The results of a statistical investigation to analyse the degree of morphological orientation of an extruded glass-ceramic based on the Li₂O-SiO₂ system are reported. Details are also presented of the determination of the crystallographic orientation in the aligned glass-ceramic.     

Crystallization and wetting of ZnO-AlO-BO-SiO glass-ceramic for sealing to Kovar alloy

A new type of ZnO-Al₂O₃-B₂O₃-SiO₂ glass-ceramics seals to Kovar in electronic packaging was developed, whose coefficient of thermal expansion (CTE) and electrical resistance were 5.2 × 10^-6/°C and over 1 × 10¹³ ?·cm, respectively. The major crystalline phases in the glass-ceramics seals were ZnAl₂O₄, ZnB₂O₄ and NaSiAl₂O₄. The dielectric resistance of the glass-ceramic could be remarkably enhanced through the control of the alkali metal ions into the crystal lattices. It was found that the crystallization happened first on the surface of the sample, leaving the amorphous phase in the inner parts, which makes the glass suitable for sealing. The glass-ceramic showed better wetting on the Kovar surface, and sealing atmosphere and temperature showed great effect on the wetting angle. Strong interfacial bonding was obtained, which was mainly attributed to the interfacial reaction between SiO₂ and FeO or Fe₃O₄.     

Fatigue and life-time of bioactive glass-ceramic A-W containing apatite and wollastonite

High-strength bioactive glass-ceramic A-W containing apatite and wollastonite shows the least dynamic fatigue among glass and glass-ceramics of the same composition and of different structure in a simulated body fluid at 38.5° C. An avenge life-time estimated from the fatigue of glass-ceramic A-W is 10 yews under continuous loading of bending stress of 65 MPa in the simulated body fluid, whereas that of a sintered dense hydroxyapatite ceramic is only 1 min. Articles of the glass-ceramic which withstand the stress of 215 M Pa in an inert atmosphere are guaranteed for 10 years life-time in the body environment. The glass-ceramic shows an increase in strength, without having an appreciable change in fatigue, when placed in the simulated body fluid without being loaded. Its practical life-time can therefore be expected to be much longer than that estimated above.     

化学组成对微晶玻璃/金属复合材料性能的影响

研究了一种新型装饰材料—微晶玻璃/金属复合材料。在微晶玻璃与金属基体复合过程中,基础玻璃组分的选择对两者结合质量有较大的影响,借助XRD、DTA及各种性能测试手段对基础玻璃及微晶玻璃和复合材料试样进行了研究,结果表明,ZnO/Al2O3>1组成的微晶玻璃与金属达到了良好的匹配,具有较好的结合强度。     

Surface-enhanced Raman spectroscopy using silver-coated porous glass-ceramic substrates

Surface-enhanced Raman scattering (SERS) has been studied using a silver-coated porous glass-ceramic material as a new type of substrate. The porous glass-ceramic is in the CaO-TiO2-P2O5 system prepared by controlled crystallization and subsequent chemical leaching of the dense glass-ceramic, leaving a solid skeleton with pores ranging in size from 50 nm to submicrometer. Silver was coated on the surface of the porous glass-ceramic by radio frequency (RF) sputtering or e-beam evaporation in vacuum. SERS spectra of excellent quality were obtained from several dyes and carboxylic acid molecules, including rhodamine 6G, crystal violet, isonicotinic acid, and benzoic acid, using this new substrate. This new substrate showed a good compatibility with these molecules. The porous glass ceramic with a nanometer-structured surface accommodated both test molecules and silver film. The absorbed molecules were therefore better interfaced with silver for surface-enhanced Raman scattering.