瓷质砖坯体的导热系数及其影响因素

探讨了温度、成型压力、含湿率、添加剂对坯体导热系数的影响。试验结果表明：对于相同化学组成的瓷质砖坯体,在保证同一实验平均温度的情况下,其导热系数随着成型压力和含湿量的增加而非线地增大;在低温段,其导热系数随着温度的升高而减小;添加物对坯体导热系数影响比较复杂。     

浅析陶瓷薄板生产工艺

我国陶瓷砖产量多年来一直位居世界第一．且陶瓷行业又是高资源依赖行业．笔者就陶瓷薄板的生产工艺进行了浅显分析,以求达到进一步加快陶瓷砖薄型化的进程。     

工艺条件对环保型透水砖基本性能的影响分析

分析了原料的颗粒大小、配方、成型压力和烧成制度等对以陶瓷废料为主要原料的多孔透水砖的力学性能、气孔率、平均孔径和透水系数等的影响，为陶瓷废料的利用开辟了一条新途径。     

电真空高铝陶瓷管产品质量控制

热压铸成型是电真空高铝陶瓷管的传统成型工艺,提高产品合格率是提高生产效率的关键点,采用该工艺,产品合格率的高低受到原材料、配方、成型、排蜡工艺、烧成制度和磨加工工艺及现场管理等各个方面的影响。重点对热压铸成型工艺控制进行了论述,热压铸成型工艺用于中、低压领域的氧化铝陶瓷真空管的生产,具有潜力可挖。     

Effects of grain size distribution and pressure on the density of magnesite brick

Conclusions With increased pressure the effects of the grain distribution on the porosity of the green compact gradually decreases.The higher the amount of fine fractions in the mixture the lower the porosity of the green compact at similar pressure. As the molding pressure increases the effect of the fineness of the ground batch on the porosity of the green compact decreases.By the introduction of grains with a maximum size of 4, 6 and 8 mm into the mixture and a simultaneous increase in the molding pressure the porosity of brick is reduced. The spalling resistance of the brick is superior to that of brick prepared from 0.0 to 2 mm fractions. Lowest spalling resistance was observed in brick made from a mass with 0.0 to 1.0 mm grains.In order to increase refractoriness-under-load by decreasing the amount of fused substances at elevated temperatures the mixture should be ground finer and the sintering temperature raised during the manufacturing of magnesite powder or brick; increased molding pressures fail to affect refractoriness-under-load.In using high-density magnesite for the production of magnesite brick which contains an insignificant amount of fused inclusions at elevated temperatures regular grinding may be applied (for small fractions) to coarse-grained mixtures and higher pressure as well as regular sintering temperatures. Brick with a low density (6.2%), a rather high spalling resistance (39 air heating — cooling cycles) and a high refractoriness-under-load (1680° C) is produced.Fon T'ienjung, Liu Kung fu, Ch'ang Ai ch'ihn, Hai Ch'eng, Sun shu sheng and Li Yu cheng participated in the study.     

钼尾矿-粉煤灰-炉渣承重蒸压砖的研制

本文利用栾川南泥湖钼尾矿、粉煤灰、炉渣为原料,以石灰、脱硫石膏为激发剂,通过正交设计研究生产承重蒸压砖的试验方法和工业试验.探寻出了影响钼尾矿-粉煤灰-炉渣承重蒸压砖强度的主要因素是成型压力,其次是水固比、骨料掺量、困料时间、钼尾矿与粉煤灰的质量比.XRD显示,钼尾矿-粉煤灰-炉渣经过蒸压产生了托勃莫莱石和方解石等水化产物,这些水化产物将未反应粗料粘结在一起,组成以粗颗粒为骨架的混凝土式结构,使得制品具有一定强度.对制品进行了性能测试表明:除具有较好的强度外,其冻融性、石灰爆裂、吸水率、耐碱、耐盐性能均良好,强度完全可以达到国家标准JC 239-2001《粉煤灰砖》规定的MU20级要求.经洛阳市金鉴工程质量检测中心检测,其各项性能均符合国家标准技术规定,放射性检验为A类建筑材料.     

Ultrasound-assisted extrusion of construction ceramic samples

The conditions for a decrease in friction during ceramic brick production between a mixture and an extruder die under the influence of 20–30 kHz ultrasound applied to the die are calculated. An optimum design of a die used to mold 30 mm diameter cylindrical samples with a resonance in this frequency range is selected using computer modeling. From the results, a titanium die is fabricated and tested on a Verdes–050 (Spain) laboratory extruder using an ultrasonic magnetostrictive transducer with a power of 1.5 kW (Inlab-Ultrazvuk, Russia). A 12% reduction in extrusion pressure, a 20% acceleration of molding and a positive influence on the properties of the ceramics were found. The surface of the ceramic samples was covered by craters with diameters of approximately 10 µm due to the boiling of water, and the porosity of the main body of the samples decreased. This technique prevents the undesirable rapid drying of the surface when the samples exit the die and stabilizes the strength of the fired samples. The color remained unchanged, the water absorption decreased, the density, strength and resistance to frost increased. Ultrasonic extrusion increased the accuracy of the strength tests of construction ceramics, indicating the prospect of ultrasonic die development for industrial extruders for bricks, facing tiles and roof tiles.     

Low-Pressure Injection Molding of Ceramic Springs

Injection molding has important advantages over other methods for the production of advanced ceramic parts with complex shapes. In this work, low-pressure injection molding was used to produce helical ceramic springs using two different kinds of molds. The ceramic powders used were submicrometer-sized alumina and partially stabilized zirconia. Sintered alumina and zirconia springs were obtained free of defects, with densities from 96% to 99% of the theoretical value. In preliminary mechanical tests, these ceramic springs supported axial deformations up to 10% before failure.     

磷石膏陶瓷透水砖的研制

本文以磷石膏为主要原料,配以天然陶瓷原料,制备了陶瓷透水砖。研究了磷石膏用量、原料配比、成型压力、及烧成制度等工艺条件对陶瓷透水砖性能的影响。结果表明:以磷石膏为主要原料,采用压制成型法可制备出性能良好的陶瓷透水砖。研究成果为磷石膏的综合利用提供了一条新途径。     

Optimization of clay properties for selecting brick molding method

The main properties of argillaceous materials governing methods for producing ceramic bricks are identified. The properties of ceramic mixtures based on Central Asia clays are optimized and recommendations for brick production technology are issued.     

Using macroporous graphene networks to toughen ZrC–SiC ceramic

Graphene is one of the important candidates in ceramic toughening due to its outstanding physical and chemical properties. For the weak interface toughening of large-diameter graphene sheet and alleviation of the interfacial reaction between ceramic precursors and graphene sheets during high-temperature pyrolysis, ZrC–SiC?Graphene composite was synthesized via a facile technology of infiltrating ceramic slurry instead of ceramic precursor into macroporous graphene network and spark plasma sintering. The incorporation of the graphene network improved fracture toughness, critical crack size, and fracture energy of ZrC–SiC ceramic. The multiple length-scale toughening mechanisms of ZrC–SiC?Graphene composite include the macroscopic toughening mechanism of crack deflection and bifurcation and the micro toughening mechanism of graphene bridging, ceramic micro zone tearing, graphene pull-out, graphene and ceramic brick slipping.     

Polymer–Ceramic Composites of 0–3 Connectivity for Circuits in Electronics: A Review

Composite technology, where a novel artificial material is fabricated by combining, for example, ceramic and polymer materials in an ordered manner or just by mixing, was earlier used widely for sonar, medical diagnostics, and NDT purposes. However, in recent decades, large numbers of ceramic–polymer composites have been introduced for telecommunication and microelectronic applications. For these purposes, composites of 0–3 connectivity (a three-dimensionally connected polymer phase is loaded with isolated ceramic particles) are the most attractive from the application point of view. Composites of 0–3 connectivity enable flexible forms and very different shapes with very inexpensive fabrication methods including simply mixing and molding. In this brief review, we gather together the research carried out within 0–3 ceramic–polymer composites for microwave substrates, also including embedded capacitor, inductor, or microwave-absorbing performances.     

伟晶石高性能陶瓷透水砖的研制

陶瓷透水砖是一种经过特殊工艺制成的具有连续孔隙的生态型环保陶瓷砖。采用伟晶石为主要原料,先将伟晶石烧制成高强轻质的陶粒,然后将高强陶粒二次烧结成陶瓷透水砖,所制成的陶瓷透水砖的抗压强度和透水性远高于JC/T945-2005《透水砖》标准要求。     

Certain Specifics of Quasi-Isostatic Molding (A Review)

The author considers specifics of the method of quasi-isostatic molding, which is the most perfect, economical, and simple method for molding products from powder materials providing for a high quality of products due to the volume compression of the molding material. The method can be used for molding articles from ceramic, metal, and graphite powders, glass ceramics, ferrite, abrasive materials, and in production of refractory articles.     

Some Types of Defects in the Static Molding of Technical Ceramics

The long-term experience of the author in the field of ceramic molding technologies is summarized and can be used by specialists for upgrading technologic processes in industrial ceramic production and for improving product quality.     

现代陶瓷工业中沸石的应用

本文介绍在陶瓷生产工艺基础上，用天然沸石矿物制备吸附剂、离子交换剂、触媒（催化剂）。还介绍用沸石矿物制备陶瓷颜料、瓷砖、泡沫微晶玻璃。     

Evaluation of the morphology and pore characteristics of silica refractory using X-ray computed tomography

Silica refractory has excellent high-temperature performance, but its apparent porosity is relatively high. In this work, samples obtained before and after creep testing of silica brick (1550 °C, 50 h), from used silica checker brick (existing only tridymite and amorphous) and from used dome brick (existing only cristobalite and amorphous) were investigated using a three-dimensional structure model based on X-ray computed tomography (CT). The results show that the porosity of silica brick was high but consisted mainly of interconnected pores, with a very small proportion of closed pores (smaller after long-term use). During the use of silica brick, the morphology and phase transformation caused large particles to rupture, and the mineralizer became liquid at high temperature. The broken particles and interconnected pores provided channels for the migration of the liquid in the brick at high temperature. The silica brick presented a homogeneous ceramic structure during long-term operation. Tridymite or cristobalite presented a solid frame leading to an excellent creep performance of the silica brick (the creep rate of the checker brick was ?0.16% at 1550 °C for 50 h). Results were discussed, compared with literature and a model for the transformation of the silica brick from a refractory structure to a homogeneous ceramic structure was established in this paper.     

The use of excess activated sludge from municipal sewage treatment works in production of construction ceramics

The composition of a ceramic mixture for production of brick using excess activated sludge from municipal sewage treatment works is developed. The properties of the samples obtained meet the requirements imposed on ceramic construction products. Assessment of the environmental safety of the suggested material was carried out and the efficiency of utilization of activated sludge in production of construction materials was demonstrated. Translated from Steklo i Keramika, No. 5, pp. 31 – 34, May, 1998.     

Thermal conductivity of traditional ceramics: Part II: Influence of mineralogical composition

The thermal conductivity of traditional ceramic materials is known to be a function of their porosity or bulk density. However, the scatter in the thermal conductivity–bulk density data in certain studies, particularly when data from industrially processed brick are involved, suggests that thermal conductivity depends, apart from porosity, on other characteristics such as mineralogical composition, microstructure, humidity, and the presence of soluble salts.A standard red-firing clay used in brick manufacture has been used in this study with a view to systematising the impact of the different variables that could influence thermal conductivity and mechanical strength. Part I of the study presented the results obtained when the dry bulk density of the pieces and their firing temperature were modified.Part II examines the influence of the mineralogical composition of the starting raw materials mixture on the thermal conductivity and mechanical strength of clay brick products. The findings suggest that to manufacture traditional ceramics with high thermal insulation and appropriate mechanical properties, it is advisable to use illitic-kaolinitic clays. Large-sized potassium feldspar and quartz particles adversely affect fired mechanical strength. In addition, quartz has high thermal conductivity. The addition of carbonates or the use of calcareous clays has a positive effect on mechanical strength, because carbonate acts as a pore-forming agent and generates crystalline phases during firing that enhance mechanical strength.     

Control of structural and flow properties of ceramic mixtures using aqueous emulsion of cutting liquid waste

The possibility of using an aqueous emulsion of cutting liquid waste in the production of construction ceramics is determined. The effect of CL waste on the structural and flow (molding) properties and the energy consumed in the molding of clay and ceramic mixtures based on Kiev spondyl clay is studied.