稀土共掺杂对Li2O-Al2O3-SiO2系微晶玻璃晶化行为及发光性能的影响

采用熔融-晶化法在空气气氛下制备了CeO2、Sm2O3共掺杂的Li2O-Al2O3-SiO2系微晶玻璃,利用差热分析仪、紫外-可见分光光度计、X射线衍射仪、扫描电镜以及荧光分光光度计等,研究了共掺杂对微晶玻璃晶化行为及其发光性能的影响.结果表明:随着CeO2掺杂量增大,微晶玻璃结晶度明显提高,玻璃的晶化温度先下降后升高,而470 nm光激发下微晶玻璃发光强度先增大后降低,晶化温度达到最低时微晶玻璃的发光强度最高.稀土离子的聚集作用是影响微晶玻璃晶化行为和发光性能的关键因素.     

稀土掺杂对Li2O-Al2O3-SiO2微晶玻璃组织和光学性能的影响

通过熔融法制备了掺杂CeO2和Nd2O3的Li2O-Al2O3-SiO2（LAS）透明微晶玻璃,利用差热分析仪、X射线衍射仪、扫描电镜、紫外可见分光光度计等检测技术,研究稀土掺杂对Li2O-Al2O3-SiO2（LAS）玻璃析晶行为以及微晶玻璃的微观结构和光学性能的影响。稀土掺杂明显提高玻璃的析晶活化能和晶化温度,抑制了微晶玻璃由石英固溶体向锂辉石固溶体的转变,使LAS微晶玻璃的热稳定性增强。微晶玻璃晶化后紫外吸收边出现＂红移＂,掺杂稀土的微晶玻璃晶粒出现细化。稀土离子的能级跃迁,导致微晶玻璃的颜色发生变化,并在晶界光散射和晶格光吸收的共同作用下,使微晶玻璃的透过率降低。     

废玻璃和粉煤灰制备微晶玻璃的快速烧结-晶化行为

以废玻璃、粉煤灰为主要原料,利用快速烧结-晶化法制备斜辉石-钙长石微晶玻璃.利用XRD和SEM研究了升温速率对微晶玻璃烧结-晶化行为和显微结构影响.结果表明,与10 ℃/min常规烧结相比,30℃/min以及烧结温度下直接置入烧结的烧结激活能显著降低,微晶玻璃体积密度更大、气孔孔径更小.快速升温时最佳烧结温度明显降低,且钙长石晶相出现择优取向生长,导致微晶玻璃抗弯强度增大,950℃下直接置入烧结的微晶玻璃抗弯强度达到最高值107 MPa.     

核化和晶化温度对温石棉尾矿制备微晶玻璃的影响

以温石棉尾矿、石灰石和石英砂为主要原料,通过不同的热处理过程制备了微晶玻璃。借助DTA、XRD及SEM等分析测试手段,研究了核化和晶化温度对微晶玻璃析晶行为、显微形貌及抗压强度的影响。结果表明:随着热处理温度的升高,微晶玻璃主晶相的种类没有改变,但主晶相衍射峰的强度呈现先增强后减小的趋势。当核化温度为820℃,晶化温度为1050℃时,微晶玻璃样品形成致密的柱状细晶结构,抗压强度达到最大值523 MPa。     

利用废玻璃和粉煤灰制备钙铝硅微晶玻璃及其性能

采用粉体直接烧结-晶化法,以废玻璃和粉煤灰为主要原料,制备了CaO-Al2O3-SiO2(CAS)微晶玻璃。利用差热-热重分析仪、X射线粉末衍射仪、扫描电子显微镜等分析手段,确定出微晶玻璃热处理工艺制度,并对微晶玻璃的晶相结构和显微组织进行了分析。结果表明:经过820℃烧结1 h,1100℃晶化热处理2 h获得的CAS微晶玻璃体积密度最大,吸水率最低;CAS微晶玻璃为单相硅灰石结构;抗弯强度最大值达81.5 MPa。     

核化和晶化时间对页岩飞灰微晶玻璃性能的影响

以页岩飞灰为主要原料,通过不同热处理过程制备了微晶玻璃.利用XRD和SEM测试手段,分析了核化时间和晶化时间对微晶玻璃晶相特征的影响.结果表明,晶化时间的增加使微晶玻璃主晶相钙长石含量降低,次晶相钙硅石含量逐渐增加;核化时间的增加有利于球状晶粒尺寸增大,晶化时间的延长使晶粒聚集成团,排列紧密.微晶玻璃具有较高的抗压强度和良好的耐腐蚀性,可作为天然石料的替代品和装饰材料.     

Na2O-CaO-SiO2系透明微晶玻璃制备及其微观结构

制备了Yb3+掺杂的Na2O-CaO-SiO2系高结晶度、透明微晶玻璃。用差热分析(DSC)初步确定基础玻璃的核化及晶化温度范围,用X射线衍射(XRD)测定微晶玻璃析出晶相,用扫描电镜(SEM)研究微晶玻璃的微观结构。结果表明:组成为53SiO2-30CaO-17Na2O(摩尔分数,%)的基础玻璃经热处理析出了Na4Ca4Si6O18晶相;合适热处理制度为:595℃核化5 h,730℃晶化1 h;所制备的微晶玻璃析晶度高,晶粒尺寸约100μm,微晶玻璃仍具有较高的透明度。     

中钛型含钛高炉渣与铬铁合金渣制备微晶玻璃

以中钛型含钛高炉渣、铬铁合金渣及废玻璃为原料,采用熔融法制备了CaO-MgO-Al2O3-SiO2（CMAS）系微晶玻璃,并通过差热分析（DTA）、X射线衍射仪（XRD）、扫描电子显微镜（SEM）等手段分析了不同原料配比对微晶玻璃晶相和性能的影响,并确定了最优原料配比。结果表明:以中钛型含钛高炉渣、铬铁合金渣及废玻璃为原料,可以制备出主晶相为透辉石,次晶相为硅灰石的微晶玻璃;随着铬铁合金渣含量的增加,样品的玻璃化转变温度和晶化温度不断降低;当中钛型含钛高炉渣质量分数为25%,铬铁合金渣质量分数为15%,废玻璃质量分数为60%时,制得的微晶玻璃晶化度约54%,体积密度2.83 g/cm3,显微硬度为650.37 HV。     

锂辉石-透辉石复相微晶玻璃的晶化及性能

通过热分析(DTA)、X射线衍射(XRD)、扫描电镜(SEM)等方法研究了添加不同量CaO和MgO对Li2O-Al2O3-SiO2系微晶玻璃晶化过程及性能的影响.随CaO,MgO添加量增加,玻璃转变温度(Tg)降低,晶化峰值温度(Tp)降低,有效频率因子v增加,但是玻璃向β-石英固溶体转变晶化活化能E增加,晶体生长指数n降低,晶化动力学参数k下降.晶化后得到了由β-石英固溶体、β-锂辉石和透辉石等晶相组成的复相微晶玻璃.通过微观结构分析发现,随CaO和MgO添加量增加,微观组织从细小等轴晶向粗大的纤维状结构转变,这表明,添加CaO和MgO在降低玻璃的熔化温度的同时,抑制了玻璃整体晶化.玻璃晶化后得到的β-锂辉石和透辉石等的复相微晶玻璃,促进了材料力学性能的提高,抗弯强度从135MPa增加到186 MPa.     

晶化温度对高炉渣微晶玻璃性能的影响

以95%炼铁高炉渣和5%钾长石为原料,采用简易的一步烧结法制备炉渣微晶玻璃.利用X荧光,DSC,XRD,SEM等分析手段研究了粉体的化学组成、热学性能和样品的物相组成及显微形貌.结果表明:不同的晶化温度对高炉渣微晶玻璃性能有较大的影响,当晶化温度为830 ℃,烧成温度为1200 ℃时,制备的微晶玻璃主晶相为钙铝黄长石,在微晶玻璃中存在大量均匀分布的微小晶粒,其抗弯强度可达88 MPa.     

钛合金高温玻璃—陶瓷保护涂料的研究

开发出一种用于高温钛合金热加工条件下的防氧化玻璃－陶瓷保护涂料，该涂料是以硼铝硅酸盐玻璃为主体，加入有机粘结剂，用水做溶剂，配制而成的水悬浮液。讨论和研究了由该涂料在高温条件下形成涂层，以及涂层对钛合金保护作用的机理和涂料配方的设计原则。通过能谱（EDS）和恒温增重的分析，比较了有涂层保护和无涂层保护钛合金片表面氧含量的差异，表明了所制备的玻璃－陶瓷涂料在高温下对钛合金有很好的保护作用。     

Preparation and properties of Ba3ZnzCo2-zFe24O41／SiO2 microcrystalline glass ceramics

Ba3ZnzCo2-zFe24O41/SiO2(Z varies from 0.0 to 1.2 in step of 0.4) microcrystalline glass ceramics were prepared by citrate sol-gel process at 1200℃ in the system of BaO-Fe2O3-CoO-ZnO-SiO2. The samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The complex dielectric constant and complex permeability of Ba3ZnzCo2-zFe24O41/SiO2 microcrystalline glass ceramics were measured in the range of 0.1-6.0 GHz by transmission/reflection coaxial line method. The natural resonance phenomenon was observed in μ”spectra for all the Ba3ZnzCo2-zFe24O41/SiO2 microcrystalline glass ceramics, which was closely affected by the substitution of Zn^2 ion.     

晶界氧吸附对SrTiO3基压敏陶瓷的作用

研究了SrTiO3基压敏陶瓷热处理过程中氧的作用。发现SrTiO3基压敏陶瓷的压敏电压U10mA与试样的厚度无关，且随着热处理温度的升高而增大。进一步的试验表明SrTiO3基压敏陶瓷的压敏特性主要受试样表面高阻层的控制。X射线光电子能谱（XPS）的Mn2p和O1s谱图表明，表面高阻层是氧在热处理过程中通过晶界的扩散和化学吸附产生的。因此，氧在晶界处的化学吸附是SrTiO3基陶瓷压敏特性产生的根源。     

溶胶凝胶过程的控制因素对堇青石陶瓷制备的影响

堇青石具有低介电系数和低烧结温度，常用在片式电感和陶瓷基板中。用溶胶．凝胶法制备堇青石粉体，通过研究溶胶-凝胶过程中的pH值对烧结性能、介电性能和微观结构的影响，探讨了溶胶．凝胶过程的工艺条件对堇青石制备的影响。发现水的量和混合溶液的pH值影响水解反应速度和一次粒子的聚集速度，从而影响粉体性能。当溶胶的pH为7时粉体的烧结性能最好。最终获得了介电系数约为4（1MHz），损耗约为0．001的低介电系数堇青石陶瓷材料。     

Corrosion behaviour of tin dioxide based electrode material at high temperature in molten soda-lime-silicate glass

Tin dioxide (SnO₂) based ceramics are used to form ceramic electrodes used in glass melting techniques. In this paper, MnO₂-doped SnO₂-based ceramics were prepared by pressureless sintering, and the evolution of the microstructure of SnO₂-based ceramics in molten glass liquid was studied by SEM, EPMA and EDX. The thin boundary phase has corrosion resistance to glass liquid at high temperatures. However, the thick intergranular layer is very easily attacked by glass liquid through the dissolution mechanism. Furthermore, the corrosion of SnO₂ grains should be controlled by the diffusion process. Based on our results, a schematic diagram illustrating the corrosion behaviour of SnO₂ based ceramics in molten soda-lime-silicate glass liquid is presented.     

Melt-casting of Y3Al5O12 (YAG) ceramics by combustion synthesis under high gravity with the addition of glass

Bulk YAG-based ceramics have been prepared by melt-casting under high gravity with the addition of glass. The glass helps to reduce the porosity and grain size of the casted ceramics. In the casting process, the glass melt can feed the shrinkage cavities produced during fast solidification of YAG. With the addition of glass, the grain boundary migration of YAG is pinned and thus grain growth is limited. The effect of the glass strongly depends on its chemical composition and crystallization behavior, where a higher SiO₂ content is necessary to avoid devitrification.     

Development of electrically conductive plasma sprayed coatings on glass ceramic substrates

The production of functional coatings on glass or glass ceramic substrates is of outstanding interest in modern product development due to the specific thermophysical properties of glasses, like low or even negative CTE, low heat conductivity and high dimensional stability. Atmospheric plasma spraying (APS) is an adequate technology for the deposition of a wide variety of materials on glasses and opens new application fields for thermal spraying technology in engineering and consumer industries.Metals are the frequent solution to produce electrically conductive layers in thermal spraying operations. Concerning applications with glass ceramic as a substrate, an intermediate oxide ceramic coating is applied before depositing the metallic layer, so that the distribution of residual stresses in the composite caused during and after the deposition process due to the mismatch in the materials thermophysical properties is minimized. However, the electrical properties required for the developed coatings presented in this paper can be fulfilled using other spraying materials, like mixed phases of oxide ceramics and metal powders, or pure ceramic materials. In this way, mono-layer electrically conductive systems which ensure the required stability and adhesion of the coating can be developed, reducing as well production time and costs.In the proposed approach, the three systems, metal oxide layer-composites, ceramic-metal mixed layers and ceramic mono-layers as conductive coatings on glass ceramics were thermally sprayed with APS. The coatings were characterized in terms of residual stress distribution and electrical conductivity. The influence of the process parameters on the coating electrical and mechanical properties was analyzed using the design of experiments (DOE) methodology.     

Investigation of the effects of process parameters on the glass-to-mold sticking force during precision glass molding

Compression glass molding is a promising manufacturing process for high precision, low cost glass optical elements. However, the conditions during glass molding are known to cause sticking between the glass workpiece and the mold surface. Materials for glass molds need to have high hardness and heat resistance, therefore cemented carbide or ceramics are often used. To mitigate the adhesion problem, a thin coating layer of inert materials is deposited on the mold surface. In this research, two different coatings, Pt-Ir and TiAlN, were applied to both tungsten carbide and silicon wafer substrates and then tested in a real molding environment. Experiments based on the design of experiment or DOE revealed factors which significantly affect the sticking force under the described forming conditions including compression hold time, cooling time and compression force. The morphology of the coatings in this research was also carefully investigated using white light interferometry and scanning electron microscopy. The methodology developed in this research can be readily applied to quantitatively test the effectiveness of different thin film coatings thus providing the optics industry a solution for high performance molding process design. Results on both WC-Co and silicon substrates also support the notion that different engineering materials can be used for mold fabrication if proper coating is applied.     

金矿尾砂微晶玻璃的制备

对以金矿尾砂为主要原料制造微晶玻璃进行了研究,根据微晶玻璃的基础组成,选择MgO-Al2O3-SiO2系统为配方依据,从最低共熔点、晶相组成和晶格匹配确定玻璃主成分并优选晶核剂;利用DTA,XRD,SEM等测试手段,研究组成及晶化工艺对析晶性能和物化行为的影响,结果表明：在金矿尾矿中添加适量的镁、铝质材料和网络结构调整氧化物,可获得主晶相为堇青石和尖晶石及顽火辉石固溶体的性能良好的微晶玻璃。     

热处理对锂铁磷酸盐玻璃电性能的影响

采用熔体淬冷方法制得锂铁磷酸盐玻璃粉体，粉体经干压成型后进行热处理，并进而测定了热处理样品的电性能。分析表明，热处理条件对该玻璃体系电性能的影响是通过对其结构的改变来实现的，主要表现在玻璃体软化和形成晶相两个方面，不同的热处理温度和热处理保温时间对载流子运动的影响不同。