Glaze Composition Research Articles

Ceramics with metallic lustre decoration. A detailed study of Islamic productions from the 9th century until the Renaissance

This paper describes research on the technological evolution of glazed ceramics with a metallic lustre decoration starting from their emergence in the Near East until the Hispano-Moresque productions. That research covers the main known Islamic production sites and periods: Abbasid (Mesopotamia); Fatimid (Egypt); Timurid, Mongol, and Safavid (Iran); Ayyubid and Mamluk (Syria); Nasrid and Hispano-Moresque (Spain). It was allowed by the access to more than hundred full preserved objects or fragments supplied by French national museums (musee du Louvre DAI, musee national du Moyen-Âge, musee national de Ceramique). The characterisation of the composition and structure of the ceramics and of their decoration is mostly done through non-destructive analyses methods. The thickness and metal content of the surface lustre layers are quantified thanks to ion beam analyses performed on a particle accelerator: PIXE (particle-induced X-ray emission) for the terracotta and glazes composition and RBS (Rutherford backscattering spectrometry) for the thickness and metal content of the lustre surface layers. The preliminary results show that the features of the decorated ceramics have undergone dramatic variations when transmitted from a production to another, not only, as expected, in the composition of terracotta and glazes, but also in the thickness, the structure and the composition distribution of the lustre layers.

THE USE OF ALTERNATIVE RAW MATERIAL IN STONEWARE GLAZES

In this study, Kutahya region's perlite with high alkali oxide content, at the present time not being assessed in the ceramic industry, was used in stoneware glazes replacing albite, orthoclase and ulexite in the starting batches. New glaze recipes were composed by adding perlite to the standard glaze composition consisting of quartz, kaolin, ulexite, albite and orthoclase. The effects of such a compositional modification on the optical parameters and melting properties of the relevant glazes fired at 1160 °C were investigated. The chemical (XRF) and mineralogical analysis (XRD) of fluxes were also determined Normal 0 21 false false false TR X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Normal Tablo"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-fareast-language:EN-US;}

An assessment study of tiles from Topkapı Palace Museum with energy‐dispersive X‐ray and Raman spectrometers

A limited number of studies concerning Ottoman ceramic technology have been performed using the scanning electron microscopy‐energy dispersive X‐ray spectrometry and micro‐Raman spectroscopy techniques. The discovery of the ceramics, which were described as ‘Iznik’, at excavation sites outside of the city of Iznik, caused disagreements over the exact origin of Iznik products. In this study, bodies, glazes, and pigments of 46 tile/ceramic shards of unknown origin, which were supplied from the vaults of Topkapı Palace Museum, and two reference tile fragments, known as Kütahya products, supplied from the demolished Surp Krikor Lusavoriç church and, additionally, two Iznik reference tiles were examined using the scanning electron microscopy‐energy dispersive X‐ray spectrometry and micro‐Raman spectroscopy techniques. Results of both techniques were evaluated together for the first time to determine the power of nondestructive Raman spectroscopy technique in differentiation of Ottoman tiles. In this work, bodies of the Kütahya tiles were found to be different than Iznik and Tekfur stone‐paste bodies, which are rich in clay rather than quartz. Two different lead‐alkali glaze compositions were found for Kütahya tiles; one was rich in PbO (over 35%) and the other one was rich in alkali (PbO less than 25%). Barite inclusions were detected in the bodies and in the glazes of some Ottoman tiles, which could be the fingerprint for the Kütahya products. It was found that the under glaze red decoration is essentially a mixture of hematite and quartz in different proportions. Shades of red decoration mainly depend on the amount of hematite in the mixture. Sixteenth century tomato red decoration contains more quartz compared with 17th century dark red decoration. This study showed that a similar technology was also applied at Kütahya in the 16th century. A linear correlation was found between the position of the Raman intense stretching peak Q3 and lead oxide content of lead‐alkali glazes, which could allow for the differentiation of Ottoman tiles based on the nondestructive Raman analysis. This study provides an important additional reference data and discussion for the Ottoman tiles. Copyright © 2011 John Wiley & Sons, Ltd.

A New Method for Processing Ceramics with Cracked Glaze

Laser processing ceramic materials is a new application of laser technique. This paper presents the study of making cracked glaze surface by laser processing. Proposed the applicable the composition of glaze, the main processing parameters of laser processing, and discussed the factors which may affect the quality of cracked glazing surface. It indicates that laser processing could be a new and easy processing method to produce the cracked glazing on the ceramic surface.

Preparation and characterization of glazes from combinations of different industrial wastes

The work reported here involves the preparation and characterization of ceramic glazes made from combinations of different industrial wastes. The wastes were float glass, granite and lime shale (a raw material waste from the oil shale industry in São Mateus do Sul, state of Paraná, Brazil), which were used to replace natural raw materials in a proportion of up to 50% in weight. The compositions were formulated using the Seger method and prepared by conventional ceramic processing. The stabilized suspensions were applied in commercial wall tile and porcelain stoneware tile, which were sintered at temperatures of 1080°C and 1150°C, respectively, using two different heating cycle. Three compositions were developed, two of which yielded opaque glazes and one a transparent glaze. Linear thermal expansion coefficients (α) of 80.10−7°C−1 to 100.10−7°C−1, and glaze softening temperatures of 600–700°C were characterized by dilatometric analysis. The glaze compositions showed chemical resistance against acid and alkaline attack after 96h, showing a mass loss of less than 0.1% in weight. The surface hardness of the glazes determined by the Mohs scale, Vickers microhardness and abrasion resistance (PEI indices) were between 6–7, 3–3.7GPa and 3–4, respectively. These properties are compatible with those of commercial glazes for wall tiles and porcelain stoneware ceramics.

Characterization of Low Firing Temperature Ceramic Glaze Using Phuket MSW and Soda Lime Cullet

The normal firing temperature of ceramic products is around 1200 °C. In order to reduce firing temperature, industrial wastes were utilized in ceramic glaze. Phuket municipal solid waste (MSW), soda lime cullet, and borax were used as raw materials for low firing temperature glazes. The glaze compositions were designed using a triaxial diagram. Stoneware ceramic body was glazed then fired at 1000 and 1150 °C for 15 minutes. Morphology and phase composition of glazes were analyzed by Scanning electron microscopy (SEM-EDS) and X-ray diffraction (XRD). Thermal expansion compatibility of Stoneware body and glazes were investigated using a dilatometer. Melting behaviour of selected glaze was analyzed by heating stage microscopy. Phuket MSW and Soda lime glass cullet can be used in high percentage as major raw materials for low firing temperature ceramic glaze that show good texture and vitrified at lower firing temperature without using any commercial ceramic frits. The firing temperature can be reduced up to 150 °C in this study.

CHARACTERIZATION OF 18TH‐CENTURY MEISSEN PORCELAIN USING SEM–EDS*

Analytical investigations of fragmented Meissen porcelains well dated to between 1725 and 1763 have been carried out using SEM–EDS. The aim of the analysis was to characterize elements in bodies, glazes and overglaze enamels in order to create a baseline data set of materials used in the manufacture of porcelain at the Meissen factory, Saxony, during the 18th century. Analyses indicate body and glaze compositions to be consistent with a post c.1720–30 date, when a change from a lime‐rich flux to a potassium‐rich flux is documented to have occurred. Overglaze enamel compositions are shown to be consistent with contemporary accounts of enamel preparations at Meissen. Overglaze enamel compositions show that mixtures of pigments, in addition to documented enamel 18th‐century preparations, were in use at Meissen between c. 1725 and 1763.

Development of Electrical Porcelain Glazes from Non-Essential Materials in Ghana Using RO/R<sub>2</sub>O, R<sub>2</sub>O<sub>3</sub>, RO<sub>2</sub> Classification

The use of non-essential materials in Ghana like granites, cocoa pod ash and shells as fluxes has been studied in the composition of a local brown glaze in the Na2O-K2O-CaO-Al2O3-SiO2 systems to support electrical porcelain glaze development which hitherto relied totally on imported glazes. Chemical analyses have been performed on the various materials and revealed the presence of the right quantities of aluminous-silicate minerals necessary for combinations in glaze development using the Segar classification. It was found that the range of 0.2 - 0.4 molecular weight of the granites, 0.1 - 0.3 for the cocoa pod ash and 0.4 - 0.8 for the shells forming the R2O/RO2 group and the ratio of 1:12 for the clay and the sand was sufficient to cause excellent melt at 1200OC when 5% - 8% of local manganese and 5% local iron oxide were added to the recipe. The molecular weights of the various oxides in the R2O group were calculated from the chemical analyses of the various materials to reflect the right quantities of the oxides. The results also indicate that holding the RO/R2O group within the above limits and varying the clay to sand ratio from1:8 - 1:12, other glaze melting surfaces from matt to gloss are achievable. Physical examination of the melted glaze on the electrical porcelain bodies showed consistent rich brown colour, well vitrified with no crazing, peeling or pin holes, at pottery temperatures of 1140 - 12000C.

X-ray fluorescence (conventional and 3D) and scanning electron microscopy for the investigation of Portuguese polychrome glazed ceramics: Advances in the knowledge of the manufacturing techniques

This work shows the first analytical results obtained by X-Ray Fluorescence (XRF) (conventional and 3D) and Scanning Electron Microscopy with Energy Dispersive System (SEM-EDS) on original Portuguese ceramic pieces produced between the 16th and 18th centuries in Coimbra and Lisbon. Experts distinguished these productions based only on the color, texture and brightness, which originates mislabeling in some cases. Thanks to lateral and spatial resolution in the micrometer regime, the results obtained with μ-XRF were essential in determining the glaze and pigment thicknesses by monitoring the profile of the most abundant element in each “layer”. Furthermore, the dissemination of these elements throughout the glaze is different depending on the glaze composition, firing temperature and on the pigment itself. Hence, the crucial point of this investigation was to analyze and understand the interfaces color/glaze and glaze/ceramic support. Together with the XRF results, images captured by SEM and the corresponding semi-quantitative EDS data revealed different manufacturing processes used by the two production centers. Different capture modes were suitable to distinguish different crystals from the minerals that confer the color of the pigments used and to enhance the fact that some of them are very well spread through the glassy matrix, sustaining the theory of an evolved and careful procedure in the manufacturing process of the glaze.

MATERIAL CHARACTERIZATION OF CERAMIC TILE MOSAIC FROM TWO 17TH-CENTURY ISLAMIC MONUMENTS IN NORTHERN INDIA

Coloured tiles from two northern Indian monuments were analysed for their body and glaze composition. The results suggest that three different groups of tiles were used, all comprising a stonepaste body with alkali glaze. One group has strong similarities to a major Indian glass group, known as high alumina mineral natron glass, while the other two are similar to Western and Central Asian plant ash glazes, although with much lower lime content. The colorants conform with those usually employed in pre-modern glazes, with lead-tin yellow Type I and Type II for opaque yellow, copper blue-turquoise, cobalt blue, manganese purple, and green through mixing of lead-tin yellow and copper blue.

The white porcelains from Dehua kiln site of China: Part I. Chemical compositions and the evolution regularity

Dehua county in Fujian province of China has a long history of white porcelain production from the Song to Qing Dynasties. The development and flourish of Dehua porcelain has always been closely related to the export trade. In this part of the study, white porcelain samples of the Song to Qing Dynasties excavated from Wanpinglun, Qudougong, Zulonggong, Jiabeishan and Xingjiao kiln sites were analyzed to investigate chemical compositions of body and glaze and the evolution regularity in the course of time. The study demonstrates that the composition of Dehua body has similar evolution regularity through the Song to Qing Dynasties with Dehua glaze, and the samples of the Ming Dynasty have extraordinary high K 2O both in bodies and glazes.

Characterization of pottery from Republic of Macedonia II. Raman and infrared analyses of glazed pottery finds from Skopsko Kale

AbstractByzantine and Ottoman pottery shards from Skopsko Kale, Republic of Macedonia (27 samples) were analyzed by infrared (IR) and micro‐Raman spectroscopies. IR spectroscopy provided data for assessing the firing temperature of the ceramic body as well as the basic mineralogical composition, while micro‐Raman spectroscopy was used for studying the glazes as well as for estimating the mineralogical composition of the ceramic body. The firing temperature of the Byzantine pottery was more uniform and ranged between 700 and 800 °C. In the case of the Ottoman pottery, a clear distinction between two different firing temperatures in the samples was made, thereby dividing them into two groups (700–800 and 800–900 °C). According to the previously established relationship between glaze composition and Raman parameters, the glazes in all analyzed samples were found to be lead‐based, with firing temperature below 700 °C. A total of 25 different mineral phases was identified in the body of the ceramics. Some pigments were also identified in the pottery glazes. Oleic acid (oil) and apatite residues (protein?) were identified in one sample. Copyright © 2009 John Wiley & Sons, Ltd.

Synthesis of Y(Al,Cr)O 3 red pigments by co-precipitation method and their interactions with glazes

New red pigment based on the system YAl 1− y Cr y O 3 ( y = 0.01–0.1) was synthesized by co-precipitation method. The precipitant was attained by mixing solutions of yttrium, aluminum and chromium nitrates, respectively, and addition of ammonia as the precipitator. The effects of chromium as dopant and glaze composition on the color shade of resulting pigments were studied. EDX analysis of the prepared pigment particles, which was embedded in glaze, showed the occurrence of reactions between some glaze constituents and pigment particles. Accordingly, a glaze which was enriched in Al 2O 3 and poor in ZnO was more suitable in point of achieving a reddish shade. The resulting pigments were characterized by using X-ray diffraction (XRD), SEM and UV–vis spectrophotometer.

Materials and technological evolution of ancient cobalt-blue-decorated ceramics: Pigments and work patterns in tin-glazed objects from Aragon (Spain) from the 15th to the 18th century AD

Cobalt-blue-decorated ceramics with tin glazes have been produced in the Iberian Peninsula since the 14th century AD and in Aragon region since the 15th century until the present time. An important ceramic trade was developed and relations with potters of other important production centres were established. Representative objects from archaeological findings could help in drawing conclusions on the technology used in the manufacture of blue-decoration ceramics. In this work, the composition of bodies and glazes of more than fifty samples of blue-decorated ceramics from Aragon was determined by ICPAES and EDX–Scanning Electron Microscopy (SEM). Based on this information, different ceramic groups could be appreciated and reference values valuable for the subsequent study of the blue decorations by means of other techniques, such as laser ablation (LA)–ICPMS, were also obtained. In particular, the data obtained permitted to unequivocally establish the use of three different types of cobalt pigments, with clear changes between areas and periods. Moreover, it is demonstrated that this evolution in the nature of the blue pigments was related to a different procedure when decorating the object, namely the application of the pigments and the drawing the designs before (under glaze) or after (on glaze) covering the ceramic with the tin glaze.

In situ non-invasive investigation on the painting techniques of early Meissen Stoneware

In situ, non-invasive investigations by means of portable X-ray fluorescence and fibre optic reflectance mid-infrared (mid-FTIR) spectroscopy of painted Böttger Stoneware objects have been carried out through the MOLAB transnational access to the Porcelain Collection of the Staatliche Kunstsammlungen in Dresden. It has been possible to gather information regarding the composition of the black glaze by applying a principal component analysis to the elemental analysis to distinguish between the variations of lead, iron and manganese compositions of each glaze. It has been furthermore feasible to combine molecular spectroscopy for characterization of the constituent painting materials, namely lead white as cerusite and hydrocerusite, the use of cinnabar, azurite and Prussian blue leading to a better knowledge of the state of conservation and utility of certain pigments that may give rise to chronology of the decorative artwork. The identification of oxalates namely whedellite and moolooite are assigned as degradation products relative to the decorative areas.

Effect of soaking time on phase composition and topography and surface microstructure in vitrocrystalline whiteware glazes

The effect of soaking period on the phase composition and topography of raw glazes was discussed. The work had two goals: (i) to establish the potential of manufacturing glazes with a desired surface structure from un-fritted formulations in a fast single cycle for tiles and (ii) to clarify the effects of shortening the firing time on the phase composition and surface roughness of traditionally fired products such as sanitaryware. The results can be applied to adjust the glaze composition for given firing cycles in order to improve the chemical resistance and to achieve the desired microstructure through controlled surface composition.

Characterization of a chromium-rich tannery waste and its potential use in ceramics

Leather industries which promote hide stabilization by the conventional chrome-tanning process are a major source of pollution because of the resultant chromium-rich wastes. In this work, an extensive characterization of such a chromium-rich waste sludge is presented, regarding its chemical composition (XRF), crystalline phase contents (XRD), organic carbon content (TOC), thermal behavior by thermogravimetry (TG) and differential scanning calorimetry (DSC), as well as its stability under chemical attack (the concentration of important ions in the leachates being determined by capillary electrophoresis) and when submitted to temperatures as high as 1100 °C, in air. The material showed the tendency to produce some undesirable, and previously non-detected hexavalent chromium when exposed to high temperatures, but after washing off the soluble salts and the elimination of the organic matter by firing, the resultant material was succesfully tested as a ceramic pigment in a conventional glaze composition usually employed in the ceramic tile industry.

Zircon-free frits suitable for single fast-firing opaque wall tile glazes and their industrial productions

Wall tile glazes with a smooth surface texture, high glossiness, and whiteness are usually based on zirconium containing frits. However, these frits are quite expensive and therefore, there have recently been certain attempts to lower the production cost such as taking suitable glass–ceramic glaze systems into an account. With the present work, the frit-based glaze compositions belonging to the K 2O–MgO–CaO–ZnO–Al 2O 3–B 2O 3–SiO 2 glass–ceramic system were studied to prepare newly synthesized wall tile glazes for industrial single fast-firing. The design of a glass–ceramic glaze for this type of tiles should ensure that the selected frit precursor is technically and commercially compatible with the manufacturing conditions generally used in the production of glazed ceramic wall tiles. The aim of the study is to develop zircon-free, frit-based, glossy opaque glass–ceramic glazes for wall tiles by optimizing the CaO/MgO and adjusting the Al 2O 3/alkali ratios in the starting frit compositions. Frit production, glaze preparation, application, and single fast-firing of wall tiles were, first of all, conducted under laboratory working conditions and then, successful recipes were adapted to the relevant industry. The frit crystallization capability and crystallization temperature range were determined by differential thermal analysis (DTA). Thermal expansion coefficient values of glazes were determined by a dilatometer. Characterization of single fast-fired glass–ceramic glazes was made by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) techniques. Colour and gloss analyses of the final glazes were measured with a spectrophotometer and a gloss meter, respectively.

Technology of Islamic lustre

Abstract Replications of the lustre layers have been produced using laboratory-controlled conditions, based on a 13th century AD lustre recipe. The characteristics of the lustre layers obtained by using different paint and glaze compositions, thermal paths and atmospheres are summarised. The key parameters needed to reproduce the colours, composition and metallic optical response shown by medieval lustres are given. Analysis of the microstructural, chemical and optical characteristics of the reproductions gives a deep insight into the conditions needed for the production of lustre layers with different colours and shines. The necessary changes and improvements in the lustre process from the beginning of the lustre production (Iraq 9th and 10th centuries AD), through the Fatimid (Egypt 11th and 12th centuries AD) and later Syrian and Persian (late 12th and 13th centuries AD) productions are reviewed.

Development of a nondestructive method for underglaze painted tiles—demonstrated by the analysis of Persian objects from the nineteenth century

The paper presents an analytical method developed for the nondestructive study of nineteenth-century Persian polychrome underglaze painted tiles. As an example, 9 tiles from French and German museum collections were investigated. Before this work was undertaken little was known about the materials used in pottery at that time, although the broad range of colors and shades, together with their brilliant glazes, made these objects stand out when compared with Iranian ceramics of the preceding periods and suggested the use of new pigments, colorants, and glaze compositions. These materials are thought to be related to provenance and as such appropriate criteria for art-historical attribution. The analytical method is based on the combination of different nondestructive spectroscopic techniques using microfocused beams such as proton-induced X-ray emission/proton-induced gamma-ray emission, X-ray fluorescence, 3D X-ray absorption near edge structure, and confocal Raman spectroscopy and also visible spectroscopy. It was established to address the specific difficulties these objects and the technique of underglaze painting raise. The exact definition of the colors observed on the tiles using the Natural Color System helped to attribute them to different colorants. It was possible to establish the presence of Cr- and U-based colorants as new materials in nineteenth-century Persian tilemaking. The difference in glaze composition (Pb, Sn, Na, and K contents) as well as the use of B and Sn were identified as a potential marker for different workshops.