Reasons for Tinting of Corundum Ceramics (A Review)

The reasons and the mechanism of processes responsible for tinting of corundum ceramics are considered in the context of published data. Practical recommendations are issued.     

泥浆浇注成形刚玉瓷生产工艺要点分析

注浆成形是一种占地面积大,劳动强度大的成形方法,但是其适应性强、生产效率高、生产成本低,特别是对于瘠性料含量高的大型刚玉瓷产品的成形,更是有效的好方法.笔者主要讨论泥浆浇注成形刚玉瓷时,在生产工艺中应控制的几个要点问题,并对可能产生的缺陷进行了分析.     

刚玉瓷成形工艺与断裂韧性K_(IC)的关系

用不同的成形工艺制备氧化铝陶瓷,测量其抗弯强度、断裂韧性等主要力学性能;并讨论了不同的成形工艺与其主要力学性能尤其是断裂韧性K_(IC)的关系。     

三组份锂质瓷烧成中的物相变化

本文研究了三组份锂质烧烧成过程中的物相变化。试验证明：１０００℃以β－锂辉石与Ａｌ－Ｓｉ尖晶石，石英反应生成β－锂辉石固体，随温度升高，β－锂辉石固溶体中ＳｉＯ２量增加，其ｄ（２０１）值变小；降温过程中，β－锂辉石固溶体从液相中析出，析晶速度较快时，其ｄ（２０１）值较小。     

关于陶瓷成型工艺的讨论

陶瓷制造经历数千年历史,直到20世纪中叶因为烧结理论的创立获得了飞速发展,上世纪七八十年代关于超细粉体制备和表征的发展,促使陶瓷工艺第二次大发展,当前阻碍陶瓷材料进一步发展的关键之一是成型工艺技术没有突破,压力成型不能满足形状复杂性和密度均匀性的要求,传统的湿法成型工艺可以获得复杂形状,但不能保证坯体的均匀性,90年代以来发展起来的多种胶体原位成型工艺和气相成型工艺有望促使成型工艺获得突破。     

Technology of Ceramics in the Context of Synergism (A Review)

Synergism as an interdisciplinary science studying self-organization processes in open systems exchanging matter (energy, material, information) with the ambient medium makes it possible to consider the course of technological operations from the most general point of view. Ceramic technology can be divided into two mains stages: a system in the production of a molded preform mainly accumulates energy in the form of free surfaces of particles and their volume defects, whereas in sintering the system mainly spends this energy on strengthening and consolidation of the product.__________Translated from Steklo i Keramika, No. 3, pp. 10 – 13, March, 2005.     

Use of Corundum Ceramics for Fine Milling of Various Materials

The wear resistance of corundum milling bodies developed by the authors is estimated compared to foreign analogs. It is established that domestic ceramics, with respect to its abrasion rate in milling electrocorundum and quartz sand, is not inferior to foreign ceramics. The kinetics of milling the specified materials is analyzed.__________Translated from Steklo i Keramika, No. 1, pp. 17 – 18, January, 2005.     

Forming of Ceramics during Firing without the Application of External Pressure

A method to form thin ceramic bodies is described in which curvature in the component is introduced at high temperature without the application of an external stress. The internal stress that drives the deformation results as a consequence of cation penetration from a coating into a substrate material. This technique has been developed for alumina substrates that are coated with layers of chromia, magnesia, titania, calcia, silica, and iron oxide. Normalized deflections of segment height to sample thickness ( A/t ) of up to 10 were observed for samples with beam geometry and A/t values of 4 were obtained for disks. The magnitude of the deflection is dependent on the amount of dopant that is applied, as well as the soak temperature and time. An analytical model has been developed to describe the magnitude of the deflections. The best agreement with the experimental data is obtained when the deflections are treated as occurring at high temperature, where the resistance to bending from stiffness effects is reduced. This forming method is shown to be suitable to produce shapes of moderate complexity, such as ceramic wave springs.     

Lithium-Bearing Heat-Resistant Ceramics (A Review)

Literature and patent data on the production and use of lithium-bearing heat-resistant ceramics are analyzed; the results of studying the properties of products made of this ceramics are summarized. It is proposed to use the specified ceramics in materials capable of operating under abrupt temperature variations. __________ Translated from Steklo i Keramika, No. 6, pp. 26 – 31, June, 2005.     

油滴釉的形成机理及烧成工艺探讨

采用对比试验与原位观察取样等方法,讨论了油滴釉合理的烧成工艺控制,提出了阶梯式升温曲线,指出油滴的形成要经历氧化铁分解、釉融体分相、晶体形成与熔解等过程。     

Thermophysical Properties of NZP Ceramics (A Review)

Data on the thermophysical properties of NZP ceramics with the NaZr₂(PO₄)₃-type structure are summarized. A system of thermal expansion regularities is proposed making it possible to predict NZP materials with controllable thermal expansion, including ultralow expansion with near-zero anisotropy. The thermodynamic functions of the reactions of synthesis of NZP phosphates are calculated and the applicability of ceramic technology is justified. It is proposed to use NZP ceramics as heat-insulating materials capable of working under abrupt temperature shifts.     

Ceramics Based on Strontium Zirconate (A Review)

The paper reviews the available published information regarding the synthesis of strontium zirconate and the properties and application areas of ceramics based on this compound. The review also draws attention to the difficulties arising in using this material.     

Quasi-Isostatic Molding in Industrial Production of Ceramics (A Review)

The advantages of quasi-isostatic molding in industrial production are demonstrated. The universality and cost-effectiveness of this method facilitated its wide implementation in mass production at various ceramic factories.     

陶瓷直接凝固注模（DCC）成型

直接凝固注模式型（ＤＣＣ）是一种陶瓷净尺寸胶态成型方法，ＤＣＣ成型的坯体具有成型密度高，密度及组分分布均匀，不含或只含少量有机物等特点，本文了ＤＣＣ成型的原理、成型过程及特点。     

Ceramics and medicine (Review)

The use of ceramics in different areas of medicine, including stomatology, orthopedics, fabrication of artificial bone prostheses, cavity fillers, in dosed administration of drugs, and in fabrication of medical instruments. Some properties and methods of fabrication of ceramic materials used in medicine are reported.     

液相前驱体浸渗工艺引入添加剂制备透明多晶氧化铝陶瓷

以Mg（NO3）2、Y（NO3）3和La（NO3）3为前驱体,采用液相前驱体浸渗工艺将添加剂MgO、Y2O3和La2O3同时引入到预烧氧化铝坯体中,在1830℃、H2气氛下保温2h烧结制备透明多晶氧化铝陶瓷。利用扫描电子显微镜和紫外一可见分光光度计对透明多晶氧化铝陶瓷的显微结构及直线透光率进行表征。结果表明：液相前驱体浸渗工艺提高了添加剂分布的均匀性,采用该工艺制备的透明多晶氧化铝陶瓷显微结构均匀,晶粒尺寸为20～50μm,在波长300～800nm内最高直线透光率达38．7％（λ=800nm,厚度为0．8mm）;而采用传统湿法球磨工艺得到的透明多晶氧化铝陶瓷晶粒尺寸大小不均,在晶界及晶粒内存有残留气孔,最高直线透光率仅为12．3％m=800nm,厚度为0．8mm）。通过液相前驱体浸渗工艺引入添加剂显著提高了透明多晶氧化铝陶瓷的直线透光率。     

Decorative Zinc-Containing Crystalline Glazes for Ornamental Ceramics (A Review)

Published data on compositions and properties of zinc-containing crystalline glazes for ornamental ceramics are summarized. Current concepts of the mechanism of crystallization and spherulite formation in a glaze coating are discussed, The possibility of controlling the crystallization process and decorative properties of glazes by varying firing conditions and parameters is demonstrated. Examples of production of tinted crystalline glazes are described.     

Application of Ceramics Based on Aluminum Oxide in Medicine (A Review)

The application of pure aluminum oxide for medical purposes is analyzed. The main properties of corundum ceramics are described.     

AlN-Pr2O3液相烧结SiC陶瓷

以AlN、Pr2O3做为SiC陶瓷液相烧结的复合助剂,选定不同的助剂含量(5wt％～ 20wt％)和不同的助剂摩尔比例(Pr2O3/AlN=1/3、1/1、3/1),在1800～2000℃温度下,采用热压和无压烧结的方法制备SiC陶瓷样品,并对这些陶瓷样品的性能进行了研究.实验结果表明,助剂比1/3组的样品显示出更有效地促进SiC陶瓷致密化,该组样品无压烧结最大相对密度为87％,热压烧结具有最高的相对密度96.1％、维氏硬度23.4 GPa、抗弯强度549.7MPa、断裂韧性5.36 MPa·m1/2,显微结构中可观察到晶粒拔出现象,断裂模式为沿晶断裂.     

Dielectric Loss to Detect Liquid Phase in Ceramics at High Temperatures

Rapidly increasing dielectric loss values, coinci nt with the formation, with increasing temperature, of small amounts of liquid phase, have been seen in an alumina doped with titania and soda (Al₂O₃-l mol^c TiO₂-0.5 mol% NaO₁₂). The method appears to have the sensitivity to detect liquids in ceramics down to 0.1% in favorable cases.