共查询到19条相似文献,搜索用时 0 毫秒
1.
H.J. Alves M.R. FreitasF.G. Melchiades A.O. Boschi 《Journal of the European Ceramic Society》2011,31(5):665-671
Porcelain stoneware tile polishing is a process that adds value to ceramic tiles due to the high gloss achieved upon reducing surface roughness. However, surface polishing removes a fine layer of the product, revealing numerous “closed” pores initially located inside the material, which may compromise some of its properties such as stain resistance. The literature indicates a possible orientation of pores on surfaces parallel to that of the use of the product. Based on this hypothesis, the present work aimed to evaluate how the thickness of the layer removed by polishing acts upon the profile of exposed surface pores, and hence, on the stain resistance of the product. The results of this study are novel and reveal that the staining tendency of porcelain stoneware tile can be altered significantly by varying the conditions of the surface wear produced by polishing. 相似文献
2.
《Ceramics International》2015,41(6):7790-7795
The scope of the present study is to develop alternative white porcelain stoneware tile compositions without using zircon (ZrSiO4) which have shown better whiteness values than standard white porcelain stoneware tile composition containing zircon. These new compositions are designed to develop anorthite crystals in the microstructure. Technological properties of compositions such as water absorption (%), firing shrinkage (%) and colour (L⁎, a⁎, b⁎) were measured and compared with standard white porcelain stoneware tile. Scanning electron microscopy (SEM), X-ray diffraction (XRD) analyses were also carried out. One of the new anorthite-based compositions was manufactured as white porcelain stoneware tile substitute of standard white porcelain stoneware containing zircon. 相似文献
3.
《Ceramics International》2017,43(9):6919-6924
Porcelain stoneware tiles are industrially processed by using high sintering temperatures and fast firing cycles that result in products characterized by an almost impervious surface layer surrounding a rather porous bulk material. Since mechanical properties are affected by porosity, the knowledge of the material stiffness is an important parameter to define the service behavior of tiles. In the present investigation, porcelain stoneware samples having different closed porosity were investigated in order to understand the influence of the porosity on the elastic constants of the materials.Based on the quantitative XRD phase composition, elastic constants have been calculated via Voigt-Reuss-Hill averaging, and the influence of porosity has been taken into account via power-law and exponential relations. It is shown that the effective elastic constants predicted by exponential and power-law relations are in agreement with experimental values. It may be concluded that for this class of materials, in the porosity range below 14–16%, both exponential and power-law relations are helpful tools to design tiles with controlled microstructure and tailored mechanical properties. 相似文献
4.
J. García-Ten A. SaburitE. Bernardo P. Colombo 《Journal of the European Ceramic Society》2012,32(4):745-752
Recent market trends for porcelain stoneware tiles indicate that there is a growing interest for lightweight products, to be used vertically, in internal walls or ventilated facades. The decorative and structural functions have now been coupled with additional features, such as thermal insulation. The optimization of all functionalities depends on a careful control of porosity, in terms of overall amount, size and morphology. In this paper, we propose fundamental correlations between mechanical properties, water absorption, porosity and technological aspects, and particle size and the amount of foaming agent (SiC). The data indicate that the addition of SiC powder with a size < 10 μm enables the fabrication of tiles possessing a suitable strength, negligible water absorption and a weight reduced by 26%. The loss of mechanical strength of the tiles and their pyroplastic deformation controls the maximum attainable decrease in weight. 相似文献
5.
Camila Tavares Brasileiro Sonia Conte Flávia Contartesi Fábio Gomes Melchiades Chiara Zanelli Michele Dondi Anselmo Ortega Boschi 《Journal of the European Ceramic Society》2021,41(11):5755-5767
Strong fluxes are needed to fire vitrified ceramics at temperatures significantly lower than those usually reached in industrial firing cycles. This work is aimed at understanding the role of strong fluxes in the microstructural evolution during sintering. Six fluxes (colemanite, ulexite, wollastonite, diopside, spodumene and phonolite) were individually added to a porcelain stoneware batch and processed in standard conditions. Compacts and fired bodies were characterized by optical dilatometry, XRD-Rietveld, SEM and measuring technological properties. Strong fluxes change the firing behaviour with a complex interplay of sintering kinetics, microstructural features, and phase composition. Every flux has its own repercussion on the properties of the liquid phase (chemical composition, degree of polymerization, viscosity and surface tension) which are key points to explain the observed microstructure, densification rates, and stability at high temperature. Batches with phonolite, wollastonite or diopside exhibit characteristics closer to standard porcelain stoneware, while spodumene and borates suffer from unsatisfactory microstructures and lower densification efficiency. 相似文献
6.
Radamez D. Darolt Maykon Cargnin Michael Peterson Agenor De Noni Jr 《International Journal of Applied Ceramic Technology》2020,17(4):1742-1751
Porcelain stoneware tile is the best class of ceramic tiles regarding technical performance. Low porosity and high glass content are some of its highlighted characteristics. The manufacturing cost is highly dependent on the feldspar content and the processing flow rate. Certain technical bottlenecks in the manufacturing steps, such as milling, forming, and firing, are intrinsically associated with limitations in the processing properties, such as the dry strength, bulk density, and pyroplastic deformation. In this work, improvements in these properties were achieved using high-energy milling (HEM) after conventional milling (CM). This study was carried out on a pilot industrial scale in the milling stage. Six experimental runs were evaluated. Slurries were spray-dried. The powders were humidified with 6.5% moisture. Specimens were conformed under a specific pressure of 45 MPa. The firing was performed using temperature ranging from 1150 to 1230°C. The use of HEM, in comparison to traditional milling for the similar particle-size distributions, has increased the dry density, +0.2 g.cm−3, dry bending strength, +1.0 MPa, and decreased the pyroplastic deformation index, −1.10−5 cm−1. These results allow an estimated thickness reduction of 10%. 相似文献
7.
Fernanda Andreola Luisa Barbieri E. Karamanova Isabella Lancellotti Mario Pelino 《Ceramics International》2008
In the present work, the feasibility to substitute feldspar raw material in a porcelain stoneware body with Panel Cathode Ray Tube (CRT) glass was investigated. A standard batch and a composition, where 35 wt.% Na-feldspar was substituted by CRT glass, were sintered at different temperatures in the range of 1000–1250 °C. The degree of the densification was studied by evaluation of the closed and total porosity, while the sintering rate was estimated by non-isothermal dilatometric measures. The variation of the crystalline phase composition was evaluated by XRD analysis. From the preliminary study other ceramic samples with different percentages of CRT glass (i.e. 2.5, 5 and 10 wt.%) were prepared and fired in industrial kiln. The sintering parameters, the microstructure and the mechanical properties were measured and compared with the standard composition. 相似文献
8.
Z. Shu J. Garcia-TenE. Monfort J.L. AmorosJ. Zhou Y.X. Wang 《Ceramics International》2012,38(1):517-526
A new ceramic powder preparation process, the droplet-powder granulation process (DPGP), was recently proposed in pursuit of energy/water conservation and environment protection for sustainable development of the ceramic industry.This study characterizes the DPGP granules and resulting pressed green compacts and compares them with those obtained using traditional spray-drying (hereafter SD) and granulation (hereafter G) processes. Powder and granule properties (granule size distribution, flowability, microstructure, yield pressure, etc.), powder pressing behaviour, and green compact properties (microstructure, bending strength, etc.) were determined. The properties of the DPGP powder and the resulting compacts displayed an intermediate performance between those of the powders and compacts obtained by the SD and G processes, demonstrating the feasibility of the DPGP process in the pre-firing stage of porcelain tile manufacture. The study also shows that, in addition to the key spray-mixing step, the subsequent rolling treatment also plays a major role in DPGP granule formation. 相似文献
9.
Z. Shu J. Garcia-TenE. Monfort J.L. AmorosJ. Zhou Y.X. Wang 《Ceramics International》2012,38(2):1479-1487
A new ceramic powder preparation process, the droplet-powder granulation process (DPGP), was recently proposed for the cleaner production of ceramic tiles. The DPGP granules and resulting pressed compacts were characterized and compared with the granules and compacts obtained by spray-drying (SD) and dry granulation (G) processes in a previous paper. The results showed the feasibility of using the DPGP in the pre-firing stage of porcelain tile manufacture.This study compares the firing behaviour and fired properties of compacts pressed from three different types of granulated powders: DPGP, SD, and G and from a non-granulated powder (NG) obtained by dry milling. The evolution of compact microstructure (porosity and pore size distribution) with firing temperature was monitored and the fired compact properties (bulk density, water absorption, and stain resistance) were determined.The study shows that the DPGP improved the sintering behaviour and final properties of the resulting porcelain tiles with respect to those obtained by the G process. However, the fired compacts prepared from the DPGP powder exhibited a higher porosity and pore size compared with those of the compacts obtained from the SD granules at the same pressing pressure. The results obtained open up the possibility of manufacturing glazed porcelain tiles with a more eco-friendly process. However, the results also indicate that polished porcelain tile manufacture by the DPGP requires further research in order to improve granule characteristics, in particular green granule deformability, which is the critical factor in porcelain tile densification and vitrification during firing. 相似文献
10.
Federica Bondioli Tiziano Manfredini Michele Giorgi Graziano Vignali 《Journal of the European Ceramic Society》2010,30(1):11-16
The aim of this investigation was the surface functionalization of industrial ceramic tiles by soluble salts addition to improve mechanical properties (resistance to scratch and wear) preserving the aesthetical aspect of the final product. This objective was pursued through the application of different solution of zirconium capable to be transformed in zirconia nanoparticles during the material sintering. The solutions, in different concentrations, were deposited (300 g/m2) on unglazed green tiles by air-brushing. The obtained products were polished and characterized in terms of microstructure, surface micromechanical and technological properties based on the UNI EN ISO reference rules. The final aesthetical aspect of the products and the obtained hue variation were evaluated by means of UV–vis spectroscopy and colorimetric analysis. 相似文献
11.
Rosa MondragonJuan Carlos Jarque J. Enrique JuliaLeonor Hernandez Antonio Barba 《Journal of the European Ceramic Society》2012,32(1):59-70
Spray-drying is a unit operation highly important in many industrial applications. In this work, the influence of the drying conditions on the final grain properties has been investigated in single droplet experiments. Porcelain tile suspensions like those used in industry have been used. The experiments have been carried out in an acoustic levitator modified to work at high temperature conditions. The effect of the flocculation state, initial solid mass load, primary particle size, air temperature and initial droplet volume on the mean porosity of the grain and its mechanical strength has been studied. The most important parameters to be considered for the porosity are the primary particle size, the initial solid mass load and the flocculation state. For the mechanical strength the significant effects are the primary particle size, the initial solid mass load, the air temperature and the cross effect of flocculation state and initial solid mass load. 相似文献
12.
《Journal of the European Ceramic Society》2005,25(4):357-365
Porcelain stoneware tiles frequently undergo a polishing process, aimed at improving their aesthetical appearence, that brings about a consistent material removal, with formation of superficial defects and opening of closed pores. The consequent degradation of surface characteristics—and especially the increased sensitivity to stains—represent the main limit to the use of polished tiles in many indoor and outdoor applications. In order to better understand the role of microstructure on the resistance to stains, a phenomenological study of staining/cleaning operations (ISO 10545 parts 14 and 16) and a thoroughful physico-microstructural characterisation of tile working surfaces (SEM, open and closed porosity, rugosimetry, MIP) were carried out on twelve industrially manufactured and polished products. Diverse staining behaviours proved to be connected with different tile microstructures, being the surface roughness as well as the amount and shape of coarser pores the most influent variables. Through a statistical approach, an empirical predictional model of the amount of stain retained by the tile surface after mild washing with warm water was set up. It is based on roughness measurements (both Ra and Rt), estimation of macropores (i.e. 1–50 μm by MIP) and pore roundness (by image analysis of SEM photomicrographs). 相似文献
13.
The fast firing technique is one of the most important ways to save energy consumption and improve production efficiency in the porcelain tile industry. In the actual production, excessively short firing cycle time easily causes the cutting edge defects. This work examines the effect of microstructure on cutting processability of a representative composition of a commercial porcelain tile fired at 1200 °C with two different firing cycles as follows: 40 min and 60 min. The phase composition and microstructure were investigated by using a combination of techniques such as X-ray diffraction (XRD) and scanning electron microscopy (SEM). The result indicated that it was beneficial to extend firing cycle (from 40 min to 60 min) for the cutting processability of porcelain tiles, which was due to the formation of positive microstructures such as secondary mullite needles and small-volume residual quartz. 相似文献
14.
《Ceramics International》2023,49(10):15065-15081
Utilizing industrial and agriculture waste materials to produce a green and sustainable mortar have widely investigated and assessed based on the mechanical and durability properties. Herein, the abrasion and freezing-thawing resistance of fly ash (FA)-ground blast furnace slag (GBFS) based geopolymer mortars incorporating high content of tile ceramic wastes (TCWs) have been evaluated experimentally and mathematically using artificial neural network (ANN). A relatively dilute (4 M) alkaline solution was used to activate the ternary blend. The TCWs was maintained as a relatively large percentage of the total binder, i.e. 50%, 60% and 70%. Once the casting process was complete, curing of the samples was performed at 27 °C. These then underwent testing at day 1, day 3, day 7 and day 28 to provide durability data for various specimen ages. Tests encompassed exposure to abrasion, ability to withstand cyclic freeze-thawing and wet-drying, and permeability to water. Investigations to establish the impact of the high TCWs proportion on the generation of sodium aluminium, calcium aluminium and calcium silicate hydrate (N, C-A-S-H) gels, respectively, included X-ray diffraction, scanning electron microscopy and Fourier-transform infrared spectroscopy. The large percentage of TCWs (70%) generated GPMs that had a minimal effect on the environment and which, by day 28, evidenced a compressive strength above 35 MPa. Augmenting the GBFS and FA content promoted the capacity to withstand freeze-thawing cycles and enhanced durability. Improved performance was also observed in scenarios associated with abrasion resistance. In addition, the proposed models proved their accuracy in which MSE, MAPE, SI were less than 1.93, while R2 of greater than 0.9 confirmed the closeness between predicted and actual results. Substitution of TCWs and FA for GBFS additionally reduced landfill problems of ceramic wastes and achieved the sustainability aims. 相似文献
15.
Effects of laser surface remelting on the molten salt corrosion resistance of yttria-stabilized zirconia coatings 总被引:1,自引:0,他引:1
Peng Yi Javad Mostaghimi Larry Pershin Pengyun Xu Xianghua Zhan Delong Jia Hao Yi Yancong Liu 《Ceramics International》2018,44(18):22645-22655
In the present study, atmospheric plasma-sprayed yttria-stabilized zirconia coatings were post-remelted by a continuous diode laser to improve the hot corrosion resistance for as-sprayed coatings. The coating surfaces were covered with a salt mixture (V2O5 and Na2SO4) and then subjected to a hot corrosion test at 1100?°C in air. The influence of laser parameters including power and scanning rate on the coating microstructure and corrosion resistance was investigated. Results showed that the hot corrosion resistance can be improved by producing a dense and smooth surface and reducing the coating permeability to the molten salt. The transformation of the hot corrosion mechanisms was clarified on the basis of the observed corrosion behaviors. A laser power of 1500?W and scanning rate of 9?mm/s can produce minimal surface roughness with few segmented cracks, which can provide improved performance of the hot corrosion resistance. 相似文献
16.
Repeatable change in electrical resistance of Si surface by mechanical and electrical nanoprocessing
The properties of mechanically and electrically processed silicon surfaces were evaluated by atomic force microscopy (AFM). Silicon specimens were processed using an electrically conductive diamond tip with and without vibration. After the electrical processing, protuberances were generated and the electric current through the silicon surface decreased because of local anodic oxidation. Grooves were formed by mechanical processing without vibration, and the electric current increased. In contrast, mechanical processing with vibration caused the surface to protuberate and the electrical resistance increased similar to that observed for electrical processing. With sequential processing, the local oxide layer formed by electrical processing can be removed by mechanical processing using the same tip without vibration. Although the electrical resistance is decreased by the mechanical processing without vibration, additional electrical processing on the mechanically processed area further increases the electrical resistance of the surface. 相似文献
17.
Aline Demarch Angela Waterkemper Djeisa Pasini Sergio Ruzza Oscar R.K. Montedo Elídio Angioletto 《Ceramics International》2021,47(17):24281-24286
This work attempts to evaluate the correlation between the roughness parameters and different standardized methodologies for determining the coefficient of friction of ceramic floor tiles. Eight different types of ceramic tiles were evaluated, and each one was characterized for their coefficient of friction/slip resistance in accordance with the standards NBR 13818, ANSI A137.1, and AS 4586. The surfaces were also characterized in relation to surface roughness by means of contact profilometry. The measured friction and roughness parameters were correlated by means of analysis of variance. The results showed a correlation tendency according to a third-degree equation for tests performed in wet conditions. The study results showed that the roughness parameters influence the coefficient of friction with a confidence level of 95%. Considering the safe values indicated for the respective standards for the evaluated methods, a Rz value of 25 μm ensures that a tested surface can be considered safe in a wet-condition test, regardless of the method used to determine the coefficient of friction. 相似文献
18.
On the basis of an idealized foam bed, a model to predict conversion in a foam-bed-reactor containing surfactant has been developed. The model takes into account the effect of surface resistance, arising due to the presence of a surface active agent, on gas absorption accompanied by a chemical reaction in a foam matrix. To verify the theory, experiments have been carried out in a semi-batch foam-bed-reactor for the absorption of air-carbon dioxide mixture in a foam of sodium hydroxide solution containing finite; concentrations of different surfactants. The surface resistance offered by the molecules of surfactant at the gas-liquid interface reduces the mass transfer rates significantly. The proposed model predicts fairly well the experimentally found depletion values of sodium hydroxide. 相似文献
19.
Multiple regression predictive models based on data acquired by near-infrared (NIR) spectrophotometry suggest that stalk surface wax components contribute towards resistance toEldana saccharina Walker in sugarcane. At least 35 sugarcane clones of known resistance were required to calibrate a predictive model that accounted for approximately 54% of the variation in resistance toEldana. Wavelengths chosen in multiple regression models suggest that alcohols and carbonyls are important in the wax contribution. Through the use of wax fractionation and gas chromatography, a high alcohol/aldehyde ratio and shorter carbon chain length appears to be associated with resistance. The use of NIR in the screening of wild germplasm and the early screening of breeding material for resistance, without prior knowledge of the biochemical mechanisms involved, is an exciting prospect. However, cause-and-effect relationships remain to be shown. 相似文献