Porcelain Bodies Research Articles

Effects of porcelain layer thickness and luting resin cement on the opalescence properties of porcelain veneers

BackgroundWhen discolored teeth are repaired with porcelain veneers, the thickness of the restorations should be increased appropriately using opaque porcelain and bonded by applying opaque luting resin cement to cover discolored substrates. However, its impact on the opalescent performance has not been reported yet.PurposeTo analyze the effects of opacity, body porcelain layer thickness, and luting resin cement on the opalescence properties of porcelain veneer restorations for discolored teeth.MethodsNinety IPS d. SIGN A3 porcelain veneer specimens were prepared via powder–paste coating and sintering. Specimens were divided into three groups according to ceramic type and cement used or not: body porcelain group as control, body/opaque porcelain group and body/opaque porcelain–resin cement composite group. Each group was subdivided into three subgroups based on the thickness, 0.50, 0.75, and 1.00 mm (n = 10). Variolink N Bleach XL luting resin cement with thickness of 0.1 mm was applied to the bottoms of body/opaque porcelain specimens to produce body/opaque porcelain–resin cement composites. The opalescence (OP) values were calculated and the micromorphological characteristics were analyzed by scanning electron microscope (SEM). Statistical analysis was performed by using ANOVA test (P < 0.05).ResultsThe opalescence values determined for the body porcelain groups with thicknesses of 0.50, 0.75, and 1.00 mm and body/opaque porcelain specimens with thicknesses of 0.45/0.05, 0.70/0.05, and 0.95/0.05 mm were 3.35 ± 0.15, 3.83 ± 0.10, 6.73 ± 0.25, 7.95 ± 0.34, 15.16 ± 0.60, and 16.49 ± 0.89, respectively. The specimens in the body and body/opaque porcelain groups exhibited significant increases in their opalescence values with increasing thickness (P = 0.00). The opalescence values of the specimens increased significantly with the addition of a 0.05 mm opaque porcelain layer (P = 0.00). The opalescence values of the composites containing body/opaque porcelain layers with thicknesses of 0.45/0.05, 0.70/0.05, and 0.95/0.05 mm and luting resin cement were 9.46 ± 0.17, 16.47 ± 0.15, and 18.38 ± 0.47, respectively. The opalescence values of the composite specimens increased significantly with an increase in the thickness of the porcelain layer(P = 0.00).ConclusionsThe opaque porcelain layer and opaque resin cement can significantly improve the opalescence properties of porcelain laminate veneers for discolored teeth, but the opalescence performance is still poor than natural teeth. The body porcelain only contributes to opalescence within a certain thickness range.

On-site micro-XRF mapping of enameled porcelain paintings and sculpture. First demonstration

We present the first study of painted enameled ceramics with a mobile micro-XRF (MA-XRF) scanning device at the Cité de la Ceramique, Sèvres on 18th to 20th century soft- and hard-paste palettes, 2D or 3D, Castel Durante 16th century majolica, two 19th century porcelain reproducing paintings by W. Bouguereau and J.-E. Aubert and a set combining a porcelain figurine and flowers mounted with gilded bronze. Major elements (Si, Ca, K, Pb for enamels and porcelain body, Cu, Zn, Au, Hg for fire gildings and gilded bronze) and many minor elements, coloring agents (Fe, Co, Mn, Cu, Cr, Ni, Sb, U, Au, Pt, Y, Ta), opacifier (As, Sn, Zn) or impurities (Ba, Ti, Bi, Rb, Sr, Zr, Y, Ta, Ga, Cl) are identified and mapped. The comparison of images obtained for different transitions of the same element provides stratigraphic information. Restorations and damage are highlighted.

Determination and interpretation of firing temperature in ancient porcelain utilizing thermal expansion analysis

This study utilizes a multidisciplinary approach, combining simulation experiments, thermal expansion analysis, XRD, SEM, and physical property assessments to investigate the firing temperature in illitic-kaolinitic porcelain. Our findings indicate that the accuracy of the thermal expansion method depends on both the actual firing temperature and dwell time. When dwell time is uncertain, the method provides a range of possible actual firing temperatures, differing by approximately 100 °C. Remarkably, as the porcelain body nears full vitrification, the determined firing temperature tends to be notably higher. A critical analysis of previous research suggests potential overestimation of ancient kiln temperatures. Additionally, our study highlights the usefulness of bulk density, water absorption, porosity, and mullite content in determining dwell time. Overall, our research offers new insights into ancient porcelain firing processes.

Development of Glaze Compositions to Increase the Durability of Decorative Paints Used in Glazed Porcelain

Colorful paint works are carried out to highlight the visuality of ornamental and tableware products, such as cups and plates. As these products come into contact with detergents, food products or grime, erosion and abrasion occur in paint and patterns over time. In this study, transparent glaze compositions that can be applied on patterned products have been developed in order to minimize wear and damage to the paint on ornamental and tableware products such as porcelain cups and plates. It is aimed to have a compatibility with the glaze layer and the porcelain body, to have high transparency and brightness. Different glaze compositions have been implemented to porcelain wares containing precious metallic paints. Then the glazed products were coducted to final firing between 870˚C-900˚C. Colours values of porcelain wares were determined with L-a-b spectrophotometer colours measurment devices and ΔE values was found to be lower than 0.50. Erosion and abrasion resistance were determined by staining test and washing test. According the results, the mass loss values are in the range of 2.7-3.4 mg (24h washing) and 7.9-8.3 mg (168 h washing). The morphology of the samples and the analysis of the phases formed during sintering were determined by X-ray diffraction (XRD) technique and scanning electron miscroscopy (SEM and EDX). Quartz-SiO2 and Albite-Na (AlSi3O8) phases were observed in the structure of the glazes. The results showed that glaze compositions with high transparency and wear resistance can be obtained with only 30% frit content.

Anorthite ceramics: grog and clay selection for lowering the sintering temperature

ABSTRACT A research investigation was conducted on two variables that are indicative of plastic raw materials based on kaolin vs. interstratified illite-smectite clay and a non-plastic admixture including grog (quartz vs. alumina) during the sintering process of an anorthite porcelain body beginning at 950°C, up to the sintering temperature. A correlation was found between the mineralogical composition and various parameters of the fired bodies. A purely anorthic sintered body can be produced using interstratified illite-smectite clay with quartz as a grog, which has the lowest coefficient of linear thermal expansion in the temperature range of 30°C to 700°C and highest bending strength – modulus of rupture of sintered body. When alumina is present in the raw material mixture, the coefficient of linear thermal expansion is lower due to the absence of the SiO2 phases. Quartz in combination with interstratified illite-smectite clay significantly reduces the sintering temperature through the formation of an amorphous melt up to the sintering temperature.

Effect of binary raw materials replacement (quartz and feldspar) for porcelain chamotte on the electro-technical siliceous porcelain properties

The hurry for ecological practices and waste control has emerged as an obligation in modern times, demanding precise strategies to restrain waste accumulation and to stimulate recycling and reuse actions to lower the climate effect. The replacement of binary raw materials for porcelain chamotte waste in siliceous porcelain was studied to obtain eco-friendly high-voltage porcelain. Quartz and feldspar were progressively replaced by 5, 10, and 15 wt.% of porcelain chamotte in a conventional siliceous electro-technical porcelain composition. The replacement effect on sintered samples at 1250°C under industrial heat treatment was evaluated by measuring the linear shrinkage, bulk density, porosity, flexural strength, and microhardness technological properties. Phase analysis was carried out by X-ray diffraction. Microstructural characteristics were studied using a scanning electron microscope. The results showed that chamotte-containing samples reached bulk densities of about 2.36 g/cm3 and a porosity percentage near zero. The maximum flexural strength value at glazed states was 87.8 MPa, for 15 wt.% scrap-containing samples. X-ray diffraction studies revealed a higher mullite phase content in chamotte-containing samples. Scanning electronic microscopy images of the polished and etched specimens show the presence of quartz grains and secondary mullite needles embedded in a feldspathic vitreous matrix. The properties reached by the chamotte-containing samples are attractive since the values obtained in terms of flexural strength, density, and porosity are compared to those reported for conventional siliceous porcelain were obtained. The most noticeable result was observed in flexural resistance. The glazed porcelain bodies showed a flexural strength improvement of about 15%. Then, these porcelain compositions suggest an alternative to produce a more sustainable, affordable, and environmentally-friendly porcelain insulator product.

Cost-effective and eco-friendly transparent ceramic glazes for porcelain bodies

Cost-effective and eco-friendly transparent ceramic glazes for porcelain bodies

Potential Uses of Local Clay Materials for the Production of Porcelain Electrical Insulators, Ethiopia

AbstractClays are extremely variable materials with different mineral compositions, and they are the main ingredients in ceramics applications. Their properties play specific roles in influencing the technological properties and performance of ceramics products. Evaluating the various properties can help to determine the best way to utilize clay materials, such as the locally available Bombawuha (BC) and Denkaka (DC) clays mined from Ethiopia's Bombawuha and Denkaka areas, respectively. The objective of this study was to examine these materials for the purpose of using them to produce quality electrical porcelain insulators. The clay samples were characterized for their chemical composition, mineralogy, thermal properties, plasticity, and particle-size distribution, using atomic absorption spectrometry (AAS), X-ray diffractometry (XRD), differential thermal analysis coupled with thermogravimetric analysis (DTA-TGA), the Atterberg plasticity test, and sieve hydrometer analysis. Based on the characteristics, suitable clay materials were selected and mixed with feldspar and quartz to formulate various porcelain body compositions which were fired at three different temperatures (1200, 1250, and 1300°C) and dwell times (1.5, 2.0, and 2.5 h). The mineralogy, water adsorption, apparent porosity, bulk density, dielectric strength, flexural strength, and microstructure of the fired bodies were measured. The results revealed that, compared to DC, BC contains kaolinite as the major mineral with appreciable amounts of silica (46.72 wt.%), alumina (35.32 wt.%), and fluxing oxides but smaller amounts of CaO. BC contains greater clay fractions (20.58 wt.%); and has a middle-range plasticity index (PI = 11.2 wt.%), thus making BC suitable for producing porcelain insulators. A test-body composition of 40 wt.% BC, 40 wt.% feldspar, and 20 wt.% quartz, fired at 1250°C for 2 h, exhibited water adsorption of 0.17 wt.%, apparent porosity of 0.42 wt.%, bulk density of 2.45 g/cm3, a dielectric strength of 8.22 kV/mm, and flexural strength of 43.63 MPa and, thus, satisfied the required properties for quality porcelain insulators.

Рецептура изделий и источники сырья Императорского Фарфорового завода в середине XVIII – начале XX века

Imperial Porcelain Factory is the first porcelain manufacture in Russia and a leader in Russian porcelain production for almost three centuries. Archive data provides evidence on changes in porcelain materials and technology on the factory. In initial period local raw materials were preferred. During the 19th and the beginning of the 20th centuries a tendency to replace them by imported ones can be traced. After the 1st World War and revolution especially the factory turns back to local raw. Due to these circumstances porcelain bodies and coatings of the factory’s diverse periods noticeably differ in chemical composition and physical properties that may serve key to differentiation of items and fakes detection. The study of the factory’s porcelain composition of differing periods may significantly facilitate attribution of Russian porcelain art pieces and be important part of investigation and conservation projects.

Archaeometric Characterization of the Industrial Production of Porcelains in the Vieillard & Co. Manufactory (Bordeaux, France, 19th Century).

In this paper, we focus on the industrial production of porcelain in the Bordeaux area (France) in the 19th century. Our main objective is to assess the evolution of production technology of the same manufactory over a period of more than 40 years. A multi-analytical approach was used to investigate glazes and bodies of thirty-four sherds of biscuit and porcelain found in an archaeological context. The microstructural, chemical, and mineralogical characterization was performed using a combination of scanning electron microscopy, coupled with energy dispersive spectroscopy (SEM-EDS), particles induced X-ray and gamma emission (PIXE-PIGE), and X-ray diffraction (XRD). Results obtained on the characterization of the ceramic production technologies and on the chemical modification over time contributes to investigate this industrial production, which is not well documented by the written archives. The examination of the biscuits, rare artifacts, showed that the porcelain bodies were produced by mixing kaolinitic clays, quartz, and potassium feldspars. The mineralogical analysis of the ceramic supports allowed hypotheses to be put forward on the temperatures of the biscuit firing (around 950 °C) and the second firing (over 1200 °C). Furthermore, the treatment of the compositional data, including both glazes and bodies, using multivariate statistical analysis, revealed different types of production corresponding to the different chronological periods of production at Bordeaux throughout the 19th century. These results will enable us to consider the possibility of authenticating non-stamped and undecorated pieces.

Analyzing the formation mechanism of ‘Huoshihong’ characteristics in the blue-and-white porcelain of the Yuan Dynasty from Jingdezhen

Energy Dispersive X-Ray Fluorescence, field emission scanning electron microscopy and X-ray Absorption Fine Structure analysis were used to study the formation mechanism of the ‘Huoshihong’ (火石红) on the blue-and-white porcelain body of the Yuan Dynasty. The color rendering component for ‘Huoshihong’ is mainly α-Fe2O3. Liquid phase forms in high temperatures due to the invasion of external flux is the primary condition of the formation of ‘Huoshihong’. Fe enrichment also occurs at the places, but the Fe2+/Fe3+ ratio where ‘Huoshihong’ occurs is similar to other areas. The formation of ‘Huoshihong’ can be divided into three stages: oxidation of the body and reduction of Fe2O3, blending of Fe2+ into the liquid phase and enriched on body surface, re-oxidation of Fe2+ and crystallization stage of nanometer-scale α-Fe2O3. Experimental archaeological results corroborate theoretical analysis showing that the appearance and re-oxidation of Fe2+ are necessary conditions for ‘Huoshihong’ formation.

Sintering of anorthite ceramic body based on interstratified illite-smectite clay

The effects of the different properties of plastic raw materials for whitewares based on different clay minerals (kaolinite vs interstratified illite/smectite [I/S]) on the sintering process (according to vacuum water absorption) was studied for anorthite porcelain body creation after firing in the range of 950–1500 °C to achieve optimal sintering temperature. The mineralogical composition of the fired bodies was observed from the firing temperature of 950 °C to the sintering temperature. Calcium carbonate decreases the sintering temperature and creates a new mineralogical phase in the fired body – anorthite – which decreases the linear thermal expansion coefficient and increases the strength (modulus of rupture) of the sintered bodies. All the described effects take place at lower firing temperatures when the I/S plastic raw material is compared with kaolin.

An In Vitro Study on the Shear Bond Strength of Feldspathic Porcelain to Nickel Chromium Alloy and Cobalt Chromium Alloy after Various Surface Treatments.

Background To evaluate and compare the shear bond strength of feldspathic porcelain to four distinctively surface-treated Ni-Cr and Co-Cr alloys and to assess the impact of oxidation-heat treatment on porcelain to base metal alloy bond strength. Methods 40 specimens each of nickel-chromium alloy and cobalt-chromium alloy were cast. A total of four groups of specimens were created. Group I was surface-treated by sandblasting with 50 μm alumina particles, Group II was surface-treated by sandblasting with 110 μm alumina particles, Group III and Group IV were surface-treated with 250 μm alumina particles. In Group IV, after sandblasting initially with 250 μm alumina particles, the alloys were subjected to oxidation and resandblasting with 250 μm alumina particles. Each of the specimen was coated with opaque and body porcelain and fired to a total thickness of 2 mm porcelain. A universal measuring machine was used to assess shear bond strength at a crosshead speed of 0.5 mm/min. Results Two-way ANOVA followed by Tukey's post hoc test was used to assess the significant difference within the groups. Unpaired t-test was used for the intergroup comparison of the obtained data. The study showed that the size of the air abrasion particles used for sandblasting significantly influenced the porcelain to metal surface bond strength, with p value <0.001. The bond strength values of the two alloys tested showed no major variations. Result also showed that oxidation influences the metal-ceramic bond strength. Conclusions The bond strength of the metal-ceramic interface is influenced by the alloy's surface treatment. The oxidation process impacts the bond strength of the metal-ceramic system.

The Mechanism of Porcelain Toughened by Activated Kaolinite in a Lower Sintering Temperature.

A high sintering temperature is usually required to acquire excellent performance in the ceramic industry, but it results in high fuel consumption and high pollution. To reduce the sintering temperature and to toughen the porcelain, a self-produced sintering additive of citric acid activated kaolinite was added to the raw material; X-ray powder diffraction (XRD), transmission electron microscope (TEM), scanning electron microscope (SEM), and thermal gravity analysis and differential scanning calorimetry (TG-DSC) were used to characterize the samples, and the toughening mechanism was discussed. The citric acid activated kaolinite obtained high activity and a large specific surface area. After introducing the activated kaolinite, the bending strength of porcelain at 1270 °C increased from 100.08 MPa to 124.04 Mpa, which was 11.45% higher than that of porcelain without activated kaolinite at 1350 °C. The results of XRD revealed that the content of mullite increased and the quartz decreased at 1270 °C, and the well-distributed needle-like mullite was observed in the images of SEM with the addition of citric acid activated kaolinite. The TG-DSC results indicated adding activated kaolinite to porcelain raw materials reduced the formation of mullite to 994.6 °C. The formation of mullite in a lower temperature served as mullite seeds in a green body during firing, and it enhanced the growth of mullite. These contributed to the appropriate phase composition and the excellent microstructure of porcelain. Thus, the distinguished mechanical performance of porcelain was obtained. Moreover, the sintering additive had no adverse effect on the porcelain body as citric acid-activated kaolinite was one of the main components of the porcelain raw material.

Structural Analysis and Optimization of Steel Pin on Cylindrical Head Suspension Porcelain Insulators

There is no essential difference in theory between the inner and outer insulating properties of cylindrical and conical head disc suspension porcelain insulators. Compared with a conical head porcelain insulator, a cylindrical head porcelain insulator is significantly lighter in weight, which can effectively reduce the mechanical load of the tower and wire; and it has better dispersion and adjustment capabilities for changes in material properties over time, so that the product is not subject to excessive and uneven stress over a long-term. In order to improve the mechanical performance of cylindrical head insulator products, this paper establishes a parameterized fine simulation model of the steel pin without changing the geometry of the insulator iron cap and porcelain body. The finite element method is used to calculate and analyze how the geometric parameters of the steel pin influence insulator mechanical properties, which can provide design reference for further product optimization.

Raman identification of the different glazing technologies of Blue-and-White Ming porcelains

Shards of Blue-and-White Ming porcelain from shipwrecks of Portuguese ships found on the coasts of South Africa plus a shard from Mombasa (Kenya) were analyzed by optical microscopy, SEM-EDS and Raman microspectroscopy (458 nm). Whereas the Raman signature of porcelain body paste compositions which are based on mullite, quartz and an amorphous phase with the minor presence of anatase and feldspar are very comparable whatever the variable alumina content, at least two types of glazes are observed: a high-temperature soda-potassium glaze, and glazes richer in calcium and similar to a celadon glaze (with the possibility of wollastonite formation). The blue decoration is obtained with a material rich in manganese typical of the Ming productions. Some shards exhibit a two-layer glaze and the blue decoration is either placed under-glaze, or in-glaze as found in the Vietnamese productions of the same period. Previous assignments of the Raman signature of feldspar to cobalt aluminate are now not favoured (blue colour is obtained with Co2+ ions dissolved in the glassy silicate) and several black spots exhibit the characteristic spectrum of an epsilon Fe2O3 phase being present.

Partial black porcelain using wood charcoal as carbon source: Characterization of porcelain body part

This paper observes the fabrication of partial black porcelain by carbon diffusion from wood charcoal as a solid carbon source, and the characterization of body at bottom area. The porcelain cup was created by conventional ceramic technique. For second firing step, the cup was set on the wood charcoal pieces contained in a closed refractory container and fired at 1250 °C for 1 h. The traces of carbon compounds at different positions on a cross-section sample were detected by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Graphitic carbon and Si − O − C were discovered. Furthermore, graphite peak was detected by X-ray diffraction (XRD). This work provides a confirmation of solid diffused carbon from wood charcoal into the porcelain body by scientific techniques.

Influence of calcined halloysite on technological & mechanical properties of wall tile body

ABSTRACT The effect of adding 0.1, 0.3, 0.6, 1.0 wt.% halloysite clay, which calcined at 600, 800, 1000 and 1200°C, to the standard wall tile slurry was studied. Wet milled halloysite was sieved with different sizes to examine the halloysite grain size effect. The granulated samples were pressed by applying a pressure of 30 MPa using a hydraulic press and made ready for sintering at 1150°C for 30 minutes. Detailed technological, mechanical and microstructural characterization studies were done on sintered samples. Compared to standard wall tile, almost all the halloysite added samples displayed similar technological properties but higher green and fired strength values. The produced sample with adding 0.6% halloysite (at 600°C calcined) by weight showed a higher firing strength with 28.75 MPa value than the minimum requirement (17.75 MPa). Observation of needlelike microstructure in the porcelain body led to establishing a simple relationship between the interlocking effects of thin needlelike mullite grains and increasing strength values. This study has shown that the addition of calcined halloysite may be an alternative to produce a thinner section wall tile product.

An AAS study of Chinese imperial yellow porcelain bodies and their place in the history of Jingdezhen's porcelain development

The bodies of 12 examples of imperial yellow Chinese porcelain dating from the early sixteenth century to the early twentieth century have been studied by atomic absorption spectroscopy. The yellow lead glaze was reserved for imperial use, and these fine monochrome porcelains played important roles in imperial rites at the summer solstice and as court wares within Beijing's Forbidden City. The project's aim has been to understand more fully the technologies used to make imperial yellow porcelains, which were significant ceramics in the history and culture of imperial China.This paper concerns the porcelain body material, particularly the nature and use of Jingdezhen's two prime body materials — porcelain stone (cishi) and kaolin (gaoling). The 12 samples studied span four centuries of imperial porcelain production and include a major change in kaolin usage at Jingdezhen in the early seventeenth century, when the proportions of kaolin used in fine porcelain bodies rose abruptly from some 20% to 50%. This study explores the natures of both prepared rocks and looks particularly at kaolin, about which some long-standing problems remain.

Artistic Expression and Material Limitations

This paper explores the iterative process of striving for artistic expressivity and developing crafting techniques in a porcelain-making project. The paper is about mitigating the tensions and flaws in porcelain bodies by trying out technical solutions while searching for genuine porcelaneous expressivity in artmaking. The paper presents examples of a working process of material-based art, from the first samples of material collapse to an exhibition of finished works in an art gallery, allowing the reader to see how faults and failures contribute to this development. The paper advocates that craft science and artistic research are closely integrated and intertwined.