烧结微晶玻璃的生产及其着色

介绍了烧结微晶玻璃的工艺原理、生产工艺,结合实践着重分析和讨论了烧结微晶玻璃的着色工艺及典型的一次着色微晶玻璃的着色剂种类和着色机理.     

高档装饰板材微晶玻璃的生产

微晶玻璃装饰板材具有优良的性能指标,与天然石材比较具有不可比拟的优势,本文介绍了微晶玻璃板材的生产特别是着色工艺,以及工业废渣在微晶玻璃生产中的应用。     

烧结法微晶玻璃着色工艺探讨

介绍了烧结法微晶玻璃装饰板的着色工艺，并结合实践对此作了简要评述。     

烧结法微晶玻璃着色工艺探讨

介绍了烧结法微晶玻璃装饰板的着色工艺，并结合实践对此作了简要评述。     

微晶玻璃的着色机理与影响因素

本文通过对以硫化物与氟化物为综合晶核剂,以CaO-A1_2O_3-SiO_2(包括K_2O-CaO-Al_2O_3-SiO_2和Na_2O-CaO一Al_2O_3-SiO_2)系统玻璃为基础组成,结晶相以硅灰石为主晶相的几种颜色的微晶玻璃,在试验与生产实践中发现,晶化工艺制度,晶核剂含量,碱金属氧化物是三种主要影响微晶玻璃颜色的因素.对微晶玻璃着色机理进行探讨和总结,得出一些经验和体会.     

矿渣微晶玻璃的研制

介绍了利用高炉炉渣制造微晶玻璃的方法。探讨了这种微晶玻璃的晶化制度、晶核剂类型以及材料着色问题。     

热处理制度对RCS系着色微晶玻璃析晶性能的影响

采用不同热处理制度对掺加硫硒化镉的R2O-CaO-SiO2 (RCS,R为Na,K)系玻璃进行显色处理得到着色微晶玻璃.通过X射线衍射、场发射扫描电镜及紫外可见分光光度计等测试分析手段研究不同热处理制度对RCS系着色微晶玻璃析晶性能的影响.结果表明:在700℃进行显色热处理,微晶玻璃的主晶相为柱状的硬硅钙石[Ca6Si...     

显色工艺对纳米CdSexS1-x微晶玻璃光吸收曲线性能的影响

采用不同的热处理显色工艺对掺杂Se和CdS着色剂的硼硅酸盐玻璃进行热处理,制备出一系列的纳米硒硫化镉颜色玻璃,研究了热处理显色工艺对玻璃光透过性能的影响。结果表明,玻璃的截止吸收波长位置取决于热处理条件;采用低温长时间热处理工艺,使所制备的玻璃具有较高的光透过率和完整的吸收边界。微观结构分析表明,热处理后玻璃中出现的纳米微晶等结构变化是导致玻璃着色、出现光截止吸收的根本原因。     

红色微晶玻璃装饰板材的研究

作者以ＣａＯ－Ａｌ２Ｏ３－ＳｉＯ２系统为基础成分，用硫硒化镉为着色剂，制备出颜色稳定的红色微晶玻璃装饰板材。并研究和讨论影响红色微晶玻璃着色的因素。     

微晶玻璃的着色工艺及其研制

通过以CaO—Al2O3-SiO2系统玻璃为基础组成，研究了着色剂含量及不同种类氧化物对该系统微晶玻璃装饰板颜色的影响，并对其着色机理及研制工艺进行了探讨和总结，得出一些经验和体会，还针对生产中容易出现的问题提出了相应的改进建议与措施。     

Recycling of Iron Sintered Wastes Into Nanoparticles Barium Hexaferrite and Zinc-Ferrite Glass-Ceramics

About 25 % of iron oxides in the sintering process are wastes. In this paper, sintered waste (SW) was used as a source of iron oxides to prepare both hard and soft magnetic glass-ceramics via a melting-quenching technique. About 71 % by wt. of sintered waste was used for preparing soft magnetic glass-ceramics, while ～46 % was used for preparing hard magnetic glass-ceramics. The comparison between ferrimagnetic glass-ceramics prepared from pure chemicals and that from sintered waste before and after heat treatment was studied. X-ray diffraction shows crystallization of both hematite and Zn-ferrite phases in sintered waste while pure Zn-ferrite or Ba-hexaferrite phases were crystallized in soft magnetic and hard magnetic glass-ceramics, prepared from sintered waste, respectively. Transmission electron microscopy determined the crystalliza- tion of nano-particles ～20 nm and <15 nm for soft and hard magnetic glass-ceramics respectively. Vibrating scanning magnetometry revealed a significant increase in saturation magnetization from ～26 emu/g for sintered waste to ～44 emu/g in soft magnetic glass ceramics while it decreased to ～12 emu/g for hard magnetic glass-ceramics.     

硅灰石型烧结微晶玻璃及其应用前景

简要介绍了硅灰石型烧结微晶玻璃的工艺原理,生产工艺,着重分析和读者论论其生产现状及存在的问题,并阐述其应用现状及前景。     

Future perspectives of biomaterials for dental restoration

The development of biomaterials that can be used to substitute metals in dental restorations represents the main challenge of future research activities until the year 2020. Therefore, the authors will focus on the presentation of two types of biomaterials for dental restoration: glass-ceramics and sintered ceramics. Dental biomaterials must have a highly aesthetic appearance that is comparable to that of natural teeth. Furthermore, they must be more durable than natural teeth and show good mechanical properties at ambient temperatures.Based on the state of the art and the latest research activities, the presentation is focused on glass-ceramics with high toughness, glass-ceramics with optical properties comparable to those of natural teeth and glass-ceramics that are processed with preferred techniques, for example, those which are moulded on different types of high-strength substrate materials. In addition, high-strength and high-toughness materials such as lithium disilicate glass-ceramics can be processed either by moulding or by a new method, that is, machining. Possible directions will be presented for moulding different types of glass-ceramics such as fluoroapatite containing glass-ceramics on high-toughness substrates made of glass-ceramics or very tough sintered ceramics.The focal point of this presentation is the demonstration of the high-strength and high-toughness sintered ceramics of the ZrO₂ type. The preferred processing method of this type of biomaterials for dental restoration is machining using CAD/CAM technologies. Future activities will be focused on improving the quality of the ZrO₂-type biomaterial. At present ZrO₂ ceramics are white opaque. One of the main aims is to achieve optical properties comparable to those of natural teeth in ZrO₂ ceramic. Therefore, the material has to be developed in special dental colours with the same mechanical properties and good durability as that of the white ZrO₂. The authors will show future directions for developing coloured ZrO₂ sintered ceramics.Future research activities will be focused on gaining a better understanding of the phenomena and mechanisms of toughening glass-ceramics and ceramics. With the acquired knowledge on the toughening mechanisms, new directions for developing ceramics until the year 2020 will be explored. The technology to achieve this goal will be applied nanotechnology.     

Mechanical and leaching properties of neodymium-contaminated soil glass-ceramics

The safe treatment of radioactive-contaminated soil is of great significance. In this work, neodymium-contaminated soil was successfully immobilized using microwave sintering to form glass-ceramics. The microstructure, morphology, elemental distribution, Vickers hardness, and chemical durability of the sintered samples were analyzed. The results showed that the glass-ceramic is more suitable to immobilize the waste compared with the glass matrix. XRD and SEM-EDS results proved that the waste form has been totally immobilized in the sintered matrix whether in glass-ceramics and glass. However, the leaching rate of element Nd in glass-ceramic was lower than the glass matrix at 28 d. Moreover, the Vickers hardness results of glass-ceramic were higher than that of glass. Thus, glass-ceramics can not only reduce sintering temperature and save energy but also achieve a better immobilizing effect. Our investigation reflects that glass-ceramics are more suitable for neodymium-contaminated soil immobilization using the microwave sintering method.     

反应析晶烧结法制备硅灰石玻璃陶瓷

本文提出了一种直接利用废玻璃制备硅灰石玻璃陶瓷的新工艺:反应析晶烧结法。将高岭土和碳酸钙为主要原料合成的析晶促进剂加入到废玻璃粉末中烧结,通过两者间的反应析出硅灰石。研究了析晶促进剂含量和烧结温度对硅灰石玻璃陶瓷的组织、烧结和性能的影响,结果表明:随着析晶促进剂含量的增加,玻璃陶瓷的体密度和开孔隙率增加,强度先增后降。提高烧结温度促进反应析晶,并导致玻璃陶瓷的体密度、开孔隙率和强度降低。析晶促进剂含量为15%,烧结温度为850℃时,制得的硅灰石玻璃陶瓷的力学性能最佳。     

Sinterability,microstructure and compressive strength of porous glass-ceramics from metallurgical silicon slag and waste glass

Porous glass-ceramics have been prepared by the direct sintering of powder mixtures of metallurgical silicon slag and waste glass. The thermal behavior of silicon slag was examined by differential thermal analysis and thermogravimetry to clarify the foaming mechanism of porous glass-ceramics. The mass loss of silicon slag below 700 °C was attributed to the oxidation of amorphous carbon from residual metallurgical coke in the silicon slag, and the mass gain above 800 °C to the passive oxidation of silicon carbide. The porosity of sintered glass-ceramics was characterized in terms of the apparent density and pore size. By simply adjusting the content of waste glass and sintering parameters (i.e. temperature, time and heating rate), the apparent density changed from 0.4 g/cm³ to 0.5 g/cm³, and the pore size from 0.7 mm to 1.4 mm. In addition to the existing crystalline phases in the silicon slag, the gehlenite phase appeared in the sintered glass-ceramics. The compressive strength of porous glass-ceramics firstly increased and then decreased with the sintering temperature, reaching a maximal value of 1.8 MPa at 750 °C. The mechanical strength was primarily influenced by the crystallinity of glass-ceramics and the interfaces between the crystalline phases and the glassy matrix. These sintered porous glass-ceramics exhibit superior properties such as light-weight, heat-insulation and sound-absorption, and could found their potential applications in the construction decoration.     

The influence of the binder on the properties of sintered glass-ceramics produced from industrial wastes

Sintered glass-ceramics were produced from coal fly ashes, red mud from aluminum production and silica fume. The capabilities of Tunçbilek fly ash and a mixture of Orhaneli fly ash, red mud and silica fume to be vitrified and devitrified by sintering process were investigated by means of scanning electron microscopy and X-ray diffraction analysis. To determine the effect of binder in the sintering technique, glass powders were pressed without or with the addition of polyvinyl alcohol. Owing to microstructural observations, density and hardness measurements, it can be said that physical properties and the hardness of the produced samples strongly depended on the crystallization degree of the samples. Toxicity characteristic leaching procedure test results showed that glass-ceramic samples produced by using sintering technique could be considered as non-hazardous materials. Chemical durability of the sintered glass-ceramic samples was also good. Microstructural investigations, hardness and physical properties of the samples indicated that the addition of polyvinyl alcohol improved the properties of sintered glass-ceramics obtained from Orhaneli fly ash, red mud and silica fume.     

Crystallization pathways in glass-ceramics by sintering cathode ray tube (CRT) glass with kaolin-based precursors

The crystallization mechanisms for the formation of glass-ceramics by sintering CRT glass with kaolin-based precursors were investigated by quantitatively determining the crystalline and amorphous phases in the products. Amorphization of sintered products was observed in CRT/kaolinite and CRT/mullite glass-ceramics systems at 700–900?°C. With the increase of temperature, the crystallochemical formation of lead feldspar and orthoclase was detected. Orthoclase was found to be the major crystalline phase in both CRT/kaolinite and CRT/mullite systems at 1000–1100?°C. When the temperature increased to 1000–1100?°C, lead feldspar was formed as the only crystalline phase to host Pb. The leaching tests suggested that the glass-ceramic product sintered by CRT/kaolin-based precursors has stronger resistance against acid attack because of the incorporation of lead into lead feldspar crystal protected by glass matrix. The incorporation of CRT glass into glass-ceramics provides a promising strategy for reducing the environmental hazard of CRT glass.     

Sintering and reactive crystal growth of diopside-albite glass-ceramics from waste glass

Diopside-albite glass-ceramics were fabricated by sintering the powder mixtures of crystallization promoters and waste glass. Two kinds of promoters were synthesized using kaolin clay, talc and chemical reagents. The crystalline phases were formed by a reactive crystallization between promoters and glass during sintering. The effect of promoter components, additions and sintering temperatures on the crystallizing and densifying behavior, microstructures and mechanical properties of glass-ceramics was investigated. The results showed that the higher densities and better mechanical properties were obtained for the glass-ceramics with 12-15% crystallization promoters sintered at 950 °C for 2 h.