Production technology and provenance study of archaeological ceramics from relevant sites in the Alcantara River Valley (North-eastern Sicily,Italy)

In this paper, volcanic-rich ceramic remains from the archaeological sites of Francavilla, Naxos and Taormina (Province of Messina, North-eastern Sicily) were studied by using inclusions as main provenance marker. Technological features, such as temper choice, vitrification degree and firing temperatures, were investigated by polarizing microscopy, X-ray diffractometry (XRD) and scanning electron microscopy (SEM). Information on the production centres was obtained through the identification of the source area of raw materials used as temper. Indeed, petrochemical analysis of the volcanic inclusions within the examined ceramics displayed strong affinities with structures/textures and compositions of the locally outcropping mugearitic products, probably ascribed to the eruptive activity of an eccentric vent of Mt. Etna (Mt. Mojo). A local production for the studied pottery samples has been therefore advanced, assuming that the used volcanic temper was easily available from the alluvial deposits along the Alcantara River stream, which is connected to the lava flow of Mt. Mojo.     

马家窑彩陶纹饰构成特征及其在平面设计中的应用

从设计艺术学的角度分析了马家窑彩陶纹饰的构成特征,并论述了马家窑彩陶纹饰的平面构成形式以及色彩构成特点。结合马家窑彩陶纹饰在现代平面设计中的具体应用,总结出了现代平面设计中民族元素的回归意识。     

The effect of temperature and humidity on interdiffusion of gold and titanium in thin films

Gold-titanium thin films are frequently used in a number of devices where gold is the conductor and titanium the bonding agent between gold and glass or ceramic substrates. Exposed to the corrosive environments, gold-titanium metallizations deteriorate and lead to failure of the devices. In this work, a preliminary study, the effect of humidity and temperature on interdiffusion of gold and titanium films was investigated. It was found that during the initial exposure period of gold-titanium thin film samples, the electrical resistance decreased. This decrease of electrical resistance occurs at temperatures as low as 70° C and can probably be ascribed to annealing processes in the samples. Exposure of the samples to higher temperatures results in the diffusion of titanium along the grain boundaries of the gold to the surface of the sample and in an increase of electrical resistance. It was observed that at 325° C titanium diffuses from grain boundaries into the gold grains and forms a gold-titanium alloy. An addition of the water vapour to the agron atmosphere does not noticeably affect the diffusion process. Optical microscope observations, of the titanium diffusion to the sample surface were confirmed by scanning electron microscopy and by X-ray fluoroscence counts in a scanning electron microscope.     

Very low loss tangent and giant dielectric properties of CaCu<Subscript>3</Subscript>Ti<Subscript>4</Subscript>O<Subscript>12</Subscript> ceramics prepared by the sol–gel process

The pure phase of CaCu₃Ti₄O₁₂ (CCTO) powder can be successfully synthesized by the sol–gel process. CCTO ceramic samples were synthesized at different sintering temperatures of 1015 and 1050?°C and sintering times of 8 and 10 h. X-ray diffraction results indicated a pure phase for all ceramic samples. Rietveld refinements were adopted for the calculation of lattice constants. Scanning electron microscopy micrographs revealed the effect of sintering conditions on the microstructural evolution of ceramic samples. X-ray absorption near edge spectroscopy was performed to determine the oxidation state of Cu and Ti ions in ceramic samples. The dielectric and non-linear current voltage properties of CCTO ceramic samples were systematically investigated. Interestingly, very low loss tangent (tanδ?<?0.017 at 30?°C and 1 kHz) and giant dielectric constant (ε′?～?10,942) with temperature coefficients less than ±15% in a wide temperature range of ?60 to 125?°C were obtained in the CCTO ceramic sample sintered at 1015?°C for 10 h (CCTO1-10). This suggests a potential use for CCTO1-10 sample in capacitor applications. All CCTO ceramic samples display non-linear characteristic with non-linear coefficient (α) and breakdown field (E _b ) values in the range of 5.69–11.02 and 1415–4294, respectively.     

Polycrystalline growth and recrystallization processes in sputtered ITO thin films

Indium tin oxide (ITO) thin films with various thicknesses from 170 to 700 nm have been grown onto unheated glass substrates by sputtering from ceramic target, and subsequently annealed in vacuum at temperatures ranging from 250 to 350 °C. The structure, morphology and electro-optical characteristics of the ITO samples have been analyzed by X-ray diffraction, atomic force microscopy, four-point electrical measurements and spectrophotometry. Polycrystalline ITO growth has been found varying with film thickness. The thickness also determined the recrystallization achievable by annealing and the electro-optical thin film properties.     

A57Fe Mössbauer study of black coring phenomena in clay-based ceramic materials

The black discoloration sometimes found in the interior cores of iron-containing clay-based ceramic materials was studied in three different samples by X-ray diffraction, elemental analysis and⁵⁷Fe Mössbauer spectroscopy. The primary cause of black coring (locally reducing conditions in the interior of the body resulting from incomplete oxidation of carbonaceous impurities) results in the formation of Fe²⁺, but, contrary to previous suggestions, the presence of discrete lower iron oxides or iron metal was not confirmed in the present samples. Instead, the Fe²⁺) was found to occur as a lattice substituent of the normal products of the high-temperature ceramic reactions (as ferroan pyroxenes, olivines or feldspars, depending on the chemical composition and reaction conditions). Thus, in the present materials, the dark core reflects the deeper colour of these ferrous minerals, which are not present in the oxidized material of the outer rim.     

传统陶器形态在玻璃酒瓶设计中的运用研究

从古代开始陶瓷器就是酒的最好载体,陶瓷和酒形成了密不可分的关系,借鉴古代陶瓷器皿造型特点,运用在现代酒瓶包装设计中是可行的,可以成为酒容器设计的新思路,提出了借鉴古代陶器造型的原则,运用重心与平衡、局部与整体、次序与节奏的视觉原理,审美性与实用性的双重性,对酒玻璃品瓶的借鉴设计进行总体的控制和把握,在此基础上提出了借鉴的设计思路,介绍了这一思路具体的设计方式和运用方法,并对成功的实列进行了分析,以求抛砖引玉的功效。     

Effect of powder reactivity on microwave sintering of alumina

Effect of the reactivity of starting alumina powder of varying crystallinity on the sintering behavior in microwave process was studied. From X-ray amorphous to highly crystalline alumina, powders were obtained by conventional heating of compacts made of the precursor amorphous powder by heating it at different temperatures from 800 to 1500 °C. These samples were then sintered in a multimode microwave field of 2.45 GHz for 10 min at 1500 °C. The microwave effect on densification of the various alumina powders was evaluated by comparing the microwave and conventional sintering data. The results show significant microwave enhancement in the densification of the samples without any pretreatment. This enhancement became less significant as the temperature of the pretreatment increased and finally diminished. Since the pretreatment at elevated temperatures made the powder more stable thermodynamically, this study indicates that the sintering enhancement of a ceramic material in microwave is a metastability-related phenomenon.     

Quantitative composition of ancient mortars from the Notre Dame Cathedral in Tournai (Belgium)

A combined micro- and macroscopical approach was implemented for the quantification of the main constituents in a set of 41 ancient mortar samples from Tournai (Belgium). The samples range in age from Roman to Romanesque. The microscopical study consisted of point counting on thin sections prepared from these mortars. If sufficiently large samples were available, Image Analysis on plane polished surfaces was used to quantify the larger objects (> 1 mm) as lime lumps or ceramics. In spite of possible uncertainties, general conclusions about these mortars could be drawn. The Roman and Palaeochristian mortars are all comparable in containing a considerable amount of ceramic fragments, whereas their presence was not systematic during later times. The binder/aggregate ratios varied from 0.4 to 2.3. Romanesque mortars seem to have a less variable binder to aggregate content compared to the older mortar samples.     

Nanocrystallization of ferroelectric lithium niobate in LiNbO3-SiO2 glasses

Transparent glasses in the (100-x)LiNbO₃-xSiO₂ system where 20 ≤ × ≤ 35, were produced by conventional melt-quenching technique. The quenched samples were amorphous as proved by X-ray diffraction (XRD) technique. Annealing of the quenched samples at temperatures ranging from 580 to 975 °C resulted in the precipitation of lithium niobate nano-crystals. Scanning electron microscopy (SEM) showed the presence of randomly oriented LiNbO₃ nano-crystals dispersed in a continuous glass matrix. The relative dielectric constant (ε_r) was in the range of 80 to 180 and increased with increasing LiNbO₃ concentration. The glass ceramic samples annealed at temperatures up to 600 °C are fully transparent.     

A new application of fiber-optic reflection spectroscopy (FORS): characterization of low-temperature alteration of chlorite schist and implications for understanding ancient stone cooking vessels

Bulk thermal alterations to chlorite schist occurring at temperatures above 450 °C are traditionally studied using X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, or thermogravimetric analysis (TGA), but lower temperature changes that lead to structural and chemical alteration, including changes in oxidation state that are not followed by a crystalline modification, are not detectable using these techniques. In this paper we present the results of the first study to examine the application of fiber-optic reflection spectroscopy (FORS) for the detection and quantification of low-temperature thermal alterations in chlorite schist. Such changes have been observed during research on the thermal behavior of medieval (12th-13th centuries AD) chlorite cooking pots from the archaeological site of Merv, Turkmenistan. FORS was used to investigate these changes, testing the archaeological samples against a model data set of experimental reference specimens. The results demonstrate the potential of FORS for tracking low-temperature thermal alterations and offer the opportunity to examine temperatures attained by ancient chlorite vessels during their past use in cooking activities.     

茶马古道上的尼西黑陶之设计实践研究

目的 以迪庆州尼西黑陶为研究对象,从现代设计学角度梳理与分析黑陶的工艺和功能特征,并从中提炼元素、造型因子进行创新设计推演实践,探索创新设计新思路。方法 首先,对尼西黑陶现状进行整理,分析其成因;然后从材质、造型、装饰方面解析黑陶的设计构成,提炼设计元素;最后从实用功能、认知功能、象征功能、审美功能等4个方面解读尼西黑陶的功能内涵,汲取设计灵感,完成设计实践。结果 尼西黑陶材质独特,饱满的造型、华美的装饰、高效的功能等都值得现代陶瓷产品设计借鉴和学习,为引领传统工艺、服务社会带来积极的影响。结论 通过对尼西黑陶的工艺与功能的梳理,展示多民族文化融合的优秀成果,并以创造性转化思维进行设计推演与实践制作,提出只有立足时代,通过矢志不渝的艺术设计实践,才能实现传统黑陶工艺的创造性转化与创新性发展,从而达到高质量传承与发展的目标。     

Effects of infiltration parameters on the synthesis of nano-laminated Ti3SiC2

In this paper, the nano-laminated Ti₃SiC₂ ceramics were fabricated by liquid silicon infiltration of gelcast porous titanium carbide (TiC) preforms. The phase compositions and microstructures of the synthesized samples at various infiltration times and temperatures were analyzed by the X-ray diffraction (XRD) technique and were observed by field emission scanning electron microscopy (FESEM). The results showed that the formed Ti₃SiC₂ decomposes to the TiC phase with the increase of infiltration time. It was found from the XRD patterns that the samples with an 88?wt% Ti₃SiC₂ MAX phase can be produced with infiltration at 1500°C for 1?h with 50 vol% solid loading and 10?wt% monomer content. It is found that the hardness and flexural strength of Ti₃SiC₂-based ceramic has been reduced with a decrease in SiC and TiC impurities and reach 5.8?GPa and 420?MPa, respectively, for the sample with 15?wt% impurity. The microstructure evaluation revealed that the purity and properties of samples were affected both through the gelcasting and infiltration parameters.     

Cytotoxic evaluation of silicon nitride-based ceramics

Silicon nitride-based ceramics are potential candidates as materials for orthopedic implants due to their chemical stability associated with suitable fracture toughness and propitious tribologic characteristics. Therefore, in this work, dense silicon nitride components are investigated considering their suitability as biomaterials. Initially, two different compositions of silicon nitride were considered, using ytterbium, yttrium and aluminum oxides as sintering aids. The materials were sintered in a carbon resistance furnace under nitrogen atmosphere and were analyzed by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM) in order to characterize the microstructure. Indentation method was applied in order to obtain hardness and fracture toughness measurements, and in vitro test of cytotoxicity was performed for a preliminary biological evaluation. A microstructure composed of grains of beta-silicon nitride distributed in a secondary phase was observed. The samples achieved fracture toughness values of 5 MPa m^1/2 and Vickers hardness values of 13 GPa. Since a nontoxic behavior has been observed during the cytotoxicity tests with the samples, this finding suggests that silicon nitride-based ceramic can be used as a material for clinical applications.     

钛基钙钛矿陶瓷粉体的溶胶-水热法合成机理研究

采用溶胶-水热法,在较低的温度下已成功地合成了多种结晶良好的纳米或亚微米钛基钙钛矿型陶瓷粉体.在本文中通过对溶胶-水热法合成PbTiO3的各阶段产物的X射线衍射谱(XRD)和红外光谱 (IR) 的分析研究,获得了其初步的合成机理:溶胶过程缩短了其反应扩散距离,促进了水热反应的进行.由于该方法合成温度低,可用于多种陶瓷亚微米粉、纳米粉的制备,因此对其反应机制的深入研究有利于纳米粉末合成技术的发展.     

Preparation of novel ceramics with high CaO content from steel slag

Steel slag, an industrial waste discharged from steelmaking process, cannot be extensively used in traditional aluminosilicate based ceramics manufacturing for its high content of calcium oxide. In order to efficiently utilize such solid waste, a method of preparing ceramics with high CaO content was put forward. In this paper, steel slag in combination with quartz, talcum, clay and feldspar was converted to a novel ceramic by traditional ceramic process. The sintering mechanism, microstructure and performances were studied by scanning electron microscope (SEM), X-ray diffraction (XRD) techniques, combined experimenting of linear shrinkage, water absorption and flexural strength. The results revealed that all crystal phases in the novel ceramic were pyroxene group minerals, including diopsite ferrian, augite and diopsite. Almost all raw materials including quartz joined the reaction and transformed into pyroxene or glass phase in the sintering process, and different kinds of clays and feldspars had no impact on the final crystal phases. Flexural strength of the ceramic containing 40 wt.% steel slag in raw materials can reach 143 MPa at sintering temperature of 1210 °C and its corresponding water absorption, weight loss, linear shrinkage were 0.02%, 8.8%, 6.0% respectively. Pyroxene group minerals in ceramics would contribute to the excellent physical and mechanical properties.     

Artificially controlling of inner structure to porous hydroxyapatite ceramic by using solidified coated fibers

Porous hydroxyapatite (HA) ceramic was fabricated by 3D fiber network. These fibers as channel underprops were treated by surface coating with acidic macromolecule glue. The solidified coated fibers in ceramic block could form run-through channels and also etch stripes on channel walls for cell attachment. The channels formed in sintering process by fibers volatilization may be directed artificially according to beforehand design of structure for ceramic block. The results showed that the pore characteristics and the inner structure of the sample made from this technique have settled for essential requests of porous bioceramic. The channels in sintered scaffold shown in SEM (scanning electron microscopy) micrographs have directional connection, equal distribution, intact configuration and existence of thin stripes on inner walls. All of these characteristics have met requests for tissue cell developing, transplanting and attaching. The samples have appropriate interconnectivity and reasonable structure with equable pore-arranging and uniform size of pore. XRD (X-ray diffraction) patterns of sample indicated no major change of the crystalline structure.     

Copper diffusion during copper cordierite cosintering

The migration of copper into cordierite during a cosintering thermochemical treatment was studied mainly by energy-dispersive X-ray spectroscopy. Various samples were studied, using pressed pellets or green tapes on which copper was applied by either screen printing or sputtering. The influence of various parameters (mainly the atmosphere and the structural state of the ceramic) is presented. It is concluded that the presence of copper in the ceramic near the interface results from two processes: a mechanical transport of copper oxide particles at low temperature and a diffusion in the amorphous phase of the ceramic at high temperature.     

Gadolinia doped ceria/yttria stabilised zirconia electrolytes for solid oxide fuel cell applications

Solid oxide fuel cells are currently constructed using a yttria stabilised zirconia electrolyte membrane. However, zirconia has a number of disadvantages associated with its use, such as the high operational temperatures required for it to exhibit acceptable levels of ionic conductivity. Alternative ceramics such as doped cerium oxide show promise as electrolytes capable of operating at reduced temperatures, but introduce additional problems such as electronic conduction and inferior mechanical properties. This paper describes the manufacture and characterisation of a number of prototype electrolytes consisting of a mixture of yttria stabilised zirconia and gadolinium doped ceria. Traditional ceramic processing techniques were used to produce the samples, which were then examined using dilatometry, impedance spectroscopy and X-ray diffraction. Results show a lowering of the ionic conductivity of zirconia with the addition of doped ceria. X-ray diffraction patterns obtained from the samples suggested that this effect could be attributed to the formation of a solid solution of ceria in zirconia.     

Aztec and Colonial Archeological Potteries: A Study on Fired Techniques

Mexican pottery, used during the Prehispanic period, showed different improvements in its manufacturing for some centuries before the arrival of Spaniards in Mexico. After this, new fired techniques were used to make ceramics during the Colonial period. Their composition, manufacturing, and fired process have not been fully understood. Photoacoustic spectroscopy (PAS), X-ray energy dispersive spectroscopy (XEDS), X-ray, transmission electron microscopy (TEM), and Mossbaüer spectroscopy studies of authentic archeological potteries of Aztec III (1450–1525), Aztec IV (1525–1550), and colonial Poblana (1780–1800) provide an understanding of different advances in their fired manufacturing. For the case of colonial Poblana pottery, some colors associated with metallic oxides, which were introduced in the Mexican colonial period, were found. The composition of the analyzed samples was mainly SiO₂, with Al, Ca, Na, Fe, S, Mg, Pb, K, Ti, and Cu impurities. Through the use of the techniques mentioned above, it was possible to determine the different processes of fired techniques associated with each type of pottery. These results were compared with archeological registers about the composition and technology in the pottery manufacturing processes.Paper presented at the Seventeenth European Conference on Thermophysical Properties, September 5–8, 2005, Bratislava, Slovak Republic.