Ceramics-Switzerland最新文献

{"title":"Influence of the Preparation Method on the Physico-Chemical and Sorption Properties of Montmorillonite","authors":"O. Golubeva, E. Brazovskaya, Yulia A. Alikina","doi":"10.3390/ceramics6020054","DOIUrl":"https://doi.org/10.3390/ceramics6020054","url":null,"abstract":"Layered silicates with a montmorillonite structure are widely used in various fields related to adsorption, gas and water treatment, catalysis, cosmetology and medicine. Under conditions of directed hydrothermal synthesis, montmorillonites with the specified characteristics can be obtained. The influence of the preparation method for montmorillonites of two compositions (Mg3Si4O10(OH)2 H2O and Na1.5Al0.5Mg1.5Si4O10(OH)2 H2O) on their sorption properties, moisture absorption, porous textural characteristics and surface properties has been studied. The nature of the initial reagents, the pH of the reaction medium and the synthesis temperature were chosen as the variable synthesis parameters. It has been established that the synthesis conditions significantly affect the properties of montmorillonite, which, in turn, determines the possibilities of using the materials obtained in specific areas.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46544910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Narrative Review of Recent Finite Element Studies Reporting References for Elastic Properties of Zirconia Dental Ceramics","authors":"L. Abu-Naba’a","doi":"10.3390/ceramics6020052","DOIUrl":"https://doi.org/10.3390/ceramics6020052","url":null,"abstract":"For fixed dentures, new generations of zirconia with diverse characteristics and design choices are of significant interest. Although in vitro studies and finite element analysis (FEA) studies have been published, comprehension of various new methods of material testing and analysis remains insufficient. Young’s modulus and Poisson’s ratio of the desired materials must be available for investigators to validate FEA investigations that are accompanied by mechanical testing. The aim of this narrative review was to find recent FEA studies that report these values for newly developed commercial CAD/CAM zirconia restorative materials and compile them in a data list. A PubMed search was performed (English articles; 2018–2023; keywords: FEA, finite element, zirconia). Full-text articles (157) were examined, including studies (36) reporting the commercial materials’ names, Young’s modulus, and Poisson’s ratio. Only 21 studies had the source of their values referenced. A list of the materials and values used in these studies was compiled. Researchers are highly recommended to trace back references to determine the origins of these values for commercial materials. New research is encouraged to test the ever expanding list of new commercial esthetic monolithic CAD/CAM zirconia materials, as well as their different translucencies, to report their Young’s modulus and Poisson’s ratio.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47557457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ceramic ZnO-SnO2-Fe2O3 Powders and Coatings -Effective Photogenerators of Reactive Oxygen Species","authors":"Larisa Khomutinnikova, S. Evstropiev, I. Meshkovskii, I. Bagrov, V. Kiselev","doi":"10.3390/ceramics6020051","DOIUrl":"https://doi.org/10.3390/ceramics6020051","url":null,"abstract":"Ceramic ZnO-SnO2-Fe2O3 powders and transparent coatings on glasses prepared using the non-isothermal polymer-salt method demonstrate a strong ability to generate chemically active oxygen species under UV and visible irradiation. Crystal structures and morphologies of these materials were studied using the XRD and the SEM analysis. It was found that there are significant differences in the crystal structure of ceramic powders and thin coatings. The powders consist of randomly oriented oxide nanocrystals of size ~47 nm. The strong orientation of the ZnO nanocrystals due to their interaction with the glass substrate is observed in the coating structure. Experimental data show that thin ceramic coatings are transparent (~90%) in the visible spectral range and the band gap of the ceramic material is 3.44 eV. The band gap value of this multi-component ceramic material is described sufficiently using Verlag’s law. Ceramic powders and coatings demonstrate the intensive photogeneration of reactive oxygen species, both in liquid and air. High photocatalytic activity of ZnO-SnO2-Fe2O3 ceramic coatings and powders was observed upon the oxidation of the diazo dye, Chicago Sky Blue. In the presence of transparent photocatalytic coating, the value of the constant rate of the dye photodecomposition was high (k = 0.056 min−1). It was found that, in spite of their short life time, photogenerated reactive oxygen species demonstrate the ability to decompose dye molecules located up to a distance of 0.5 mm from the surface of ceramic coating. Obtained experimental results suggest that the prepared ceramic materials are promising for different practical applications of the photocatalytic materials.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41380897","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Processing and Tribological Properties of PEO Coatings on AlZn5.5MgCu Aluminium Alloy with Incorporated Al-Cu-Fe Quasicrystals","authors":"E. Torskaya, Alexei V. Morozov, V. Malyshev, O. Shcherbakova","doi":"10.3390/ceramics6020049","DOIUrl":"https://doi.org/10.3390/ceramics6020049","url":null,"abstract":"The modification of ceramic PEO coatings developed for friction units is in trend of modern research aimed at the improvement of friction and wear. This study presents ceramic coatings formed on AlZn5.5MgCu aluminum alloy by microarc oxidation (PEO) in a one-stage technological process with inclusions of Al-Cu-Fe quasi-crystals. The technology of rubbing quasi-crystals into the surface of the coating during final polishing was also used. Friction and wear tests, followed by analysis of the surface and cross-sections by SEM microscopy, showed that quasicrystals affect the coating structure and frictional characteristics. The addition of a small amount of modifier to the electrolyte (0.5 percent), as well as rubbing-in technology, can reduce the coefficient of friction (up to 16 percent) and wear rate (up to 43 times) compared to pure ceramic coatings. More modifier provides a negative result.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44354600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Influence of the Burning Environment on the Properties of Ceramic Products Based on Fusible Raw Materials","authors":"Maratbek T. Zhuginissov, R. E. Nurlybayev, Yelzhan S. Orynbekov, Z. Zhumadilova, Yerlan Y. Khamza, M. Bulenbayev","doi":"10.3390/ceramics6020050","DOIUrl":"https://doi.org/10.3390/ceramics6020050","url":null,"abstract":"The purpose of this work was to investigate the effect of the burning environment on the properties and phase composition of clinker-based ceramic specimens made from loam with diatomite and bentonite clay in order to develop technological parameters for the manufacture of clinker products. The main raw material used for the experiments was local fusible loam from the Almaty deposit, which is the basis for the production of 75 and 100 grade ceramic bricks. Diatomite from Utesai deposit (Aktobe region) and highly plastic bentonite clay from Darbazin deposit (Turkestan region) were used as additives. Loam and bentonite clay were applied after grinding and sieving through a 1 mm sieve. Diatomite was applied after grinding and milling until it had completely passed through a 0.315 mm sieve. The raw materials are mixed after dosing, and then water is added in the amount required until a pliable mass is obtained. To investigate the properties of the products, standard cylinder samples were prepared with a diameter of 50 mm and a height of 50 mm. The cylinder samples were pressed on a hydraulic press at a pressure of 2–4 kN. The samples were dried in a desiccator at 95–100 °C for 2 h. After drying, the products were burning in a muffle kiln. The analysis of the properties of the burned products showed that the optimum ratio in the ceramic mixture of loam and diatomite to loam and bentonite clay is 85%:15%. After burning in a slightly oxidising environment at 1170 °C, the ceramic specimens correspond to Class 2 for the medium-density and compressive strength grades M 400 and M 500 (GOST 530-2012 (Government standard). X-ray diffractometric analysis showed that the products contain augite, quartz and anorthite as crystalline phases, with the former predominating. After burning in a reducing atmosphere, at 1170 °C, the properties of the samples have higher values compared to the samples burning in a weakly oxidising atmosphere. The resulting properties, according to the regulations, are characteristic of clinker bricks (DIN V 105-1 (technical requirements for clinker façade bricks). After burning in a reducing environment, the phase composition of the products changes qualitatively; in addition to augite and quartz, albite, diopside, orthoclase and haematite are present in the samples.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43574121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development of Lightweight Geopolymer Composites by Combining Various CDW Streams","authors":"Dimitrios Kioupis, A. Skaropoulou, S. Tsivilis, G. Kakali","doi":"10.3390/ceramics6020048","DOIUrl":"https://doi.org/10.3390/ceramics6020048","url":null,"abstract":"This study regards the development of lightweight geopolymer composites through the valorization of various construction and demolition wastes. Brick waste was utilized as the sole aluminosilicate precursor for the geopolymerization reactions, expanded polystyrene and polyurethane wastes were used as artificial lightweight aggregates, and short polyethylene fibers developed from CDWs reinforced the geopolymer matrix. The curing conditions of the geopolymer synthesis were optimized to deliver a robust geopolymer matrix (T = 25–80 °C, t = 24–72 h). Both raw materials and products were appropriately characterized with XRD and SEM, while the mechanical performance was tested through compressive strength, flexural strength, Poisson’s ratio and Young’s modulus measurements. Then, a comprehensive durability investigation was performed (sorptivity, wet/dry cycles, freeze/thaw cycles, and exposure to real weather conditions). In contrast to polyurethane waste, the introduction of expanded polystyrene (0.5–3.0% wt.) effectively reduced the final density of the products (from 2.1 to 1.0 g/cm3) by keeping sufficient compressive strength (6.5–22.8 MPa). The PE fibers could enhance the bending behavior of lightweight geopolymers by 24%; however, a geopolymer matrix–fiber debonding was clearly visible through SEM analysis. Finally, the durability performance of CDW-based geopolymers was significantly improved after the incorporation of expanded polystyrene aggregates and polyethylene fibers mainly concerning freeze/thaw testing. The composite containing 1.5% wt. expanded polystyrene and 2.0% v/v PE fibers held the best combination of properties: Compr. Str. 13.1 MPa, Flex. Str. 3.2 MPa, density 1.4 g/cm3, Young’s modulus 1.3 GPa, and sorptivity 0.179 mm/min0.5.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42875092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of Defects in Surface Layer of Al2O3/TiC and SiAlON Ceramics on Physical and Mechanical Characteristics","authors":"S. Grigoriev, M. Volosova, A. Okunkova, S. Fedorov","doi":"10.3390/ceramics6020047","DOIUrl":"https://doi.org/10.3390/ceramics6020047","url":null,"abstract":"The paper studies the influence of diamond grinding, lapping, and polishing on the surface layer and defectiveness of the Al2O3/TiC and SiAlON ceramic samples. The index of defectiveness ID, which is the product of the defect density and the defective layer’s thickness (Rt), and a method for its evaluation are proposed to quantify the defectiveness of the ceramic surfaces. Lapping reduces the Rt parameter by 2.6–2.7 times when the density of defects was decreased by 2 times. After polishing, the Rt parameter decreases to 0.42 μm for Al2O3/TiC and 0.37 μm for SiAlON samples. The density of defects decreases many times after polishing: up to 0.005 and 0.004, respectively. The crack resistance of the polished samples increased by 5–7%. The volumetric wear of polished samples decreased by 1.5–1.9 times compared to the ground ones after 20 min of abrasion wear. The polished samples show a decrease in the coefficient of friction at 800 °C and a decrease in the volumetric wear by 1.5 and 1.3 times, respectively, compared to the ground ones after 200 m of friction distance. The volumetric wear at high-temperature friction of sliding for polished specimens was 55% and 42% less than for the ground ones, respectively.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44072993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of the Phase Formation Processes and Their Influence on the Change in the Optical and Shielding Characteristics of 0.25ZnO–0.25Al2O3–0.25WO3–0.25Bi2O3 Ceramics","authors":"A. Seitbayev, A. Kozlovskiy, D. Borgekov, M. Zdorovets","doi":"10.3390/ceramics6020046","DOIUrl":"https://doi.org/10.3390/ceramics6020046","url":null,"abstract":"The phase formation processes in 0.25ZnO–0.25Al2O3–0.25WO3–0.25Bi2O3 ceramics with variation in the thermal annealing temperature were evaluated in this study. According to the obtained data on the phase composition dependent on the annealing temperature, the phase transformation dynamics, which can be written in the form of ZnO/Bi2O3/WO3/Al2O3 → ZnBi38O60/ZnO/Bi2WO6/WO3 → Bi2Al4O9/ZnBi38O60/Bi2WO6/ZnO/WO3 → ZnWO4/Bi2WO6/ZnAl2O4/ZnO → ZnWO4/Bi2WO6/ZnAl2O4 → Bi2WO6/ZnWO4/ZnAl2O4 → ZnAl2O4/Bi2WO6/Bi2W2O9, were established. It has been found that the formation of phases of complex oxides of the ZnWO4, Bi2WO6 and Bi2W2O9 types in the composition of ceramics leads to an increase in the density of ceramics up to 8.05–8.10 g/cm3, which positively affects the shielding efficiency and strength characteristics. According to the data on the change in strength characteristics, it was found that a change in the density of ceramics from 6.3 to 8.05–8.10 g/cm3 leads to strengthening and an increase in the crack resistance of ceramics by 75–80%, which indicates a high strength of ceramics and their increased resistance to external influences. As shown by the evaluation of the shielding characteristics, an increase in the density of ceramics due to a phase composition change leads to an increase in the shielding efficiency and a decrease in gamma intensity by a factor of 3–3.5. At the same time, on the base of the data presented, it can be concluded that ceramics obtained in the range of 900–1100 °C have both high shielding characteristics and high strength and resistance to external influences.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46496684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Laboratory, Clinical-Related Processing and Time-Related Factors’ Effect on Properties of High Translucent Zirconium Dioxide Ceramics Intended for Monolithic Restorations A Systematic Review","authors":"Camilla Johansson, Sebastian Franco Tabares, C. Larsson, E. Papia","doi":"10.3390/ceramics6010045","DOIUrl":"https://doi.org/10.3390/ceramics6010045","url":null,"abstract":"Because new zirconia materials are constantly being developed, the aim was to identify and qualitatively synthesize research on how processing and time-related factors affect the properties of high translucent (HT) zirconia intended for monolithic restorations. Cochrane Library, PubMed, Scopus, Web of Science, and reference lists were searched for in vitro and clinical studies. Eligibility and risk of bias were assessed. A synthesis of 142 publications was performed. HT 3Y-TZP was the most common, followed by 5YSZ, 4YSZ, and multilayer. In the laboratory, HT 3Y-TZP should be sintered according to the manufacturer’s recommendation and polished before glazing to favour strength, roughness, and wear behaviour. In the clinic, polishing is necessary after grinding to favour roughness and aging resistance. Over time, when using hydrothermal aging, t–m phase transformation and reduced translucency are expected, without affecting the strength and roughness. The strength of 4YSZ and 5YSZ is unaffected. However, the time-related methods are of questionable clinical significance. The evidence of all other factors’ effects on the properties of HT zirconia is lacking or limited; thus, these factors are of relevance for future research. There is a high heterogeneity of study designs and methods, and the results are brand-dependent.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46104813","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Affect of the Scattering Asymmetry by Structural Element of Thermal- or Environmental-Barrier Ceramics on Subsurface Radiant Overheating","authors":"V. Merzlikin, Evgeny Safonov, A. Kostyukov, S. Parshina, Anna Dokukina","doi":"10.3390/ceramics6010044","DOIUrl":"https://doi.org/10.3390/ceramics6010044","url":null,"abstract":"The problem of the formation and estimation of a thermoradiant and temperature field in ceramics Thermal- Environmental-Barrier Coatings (TBC/EBC) has been considered with complex heat transfer but under the influence of the penetrating intense radiant component. The authors proposed to analyze not only TBC but also EBC from the point of view of the optics of semitransparent scattering and absorbing media in the range of ~0.4–4 μm of external radiant action. This paradigm allows us to continue the study of ceramic fibers embedded in ceramic matrix CMCs (C/C, C/SiC, SiC/SiC) as a traditional class of opaque materials. However, at the same time, mullites, Al2O3/Al2O3 have been reviewed as a class of semitransparent elements for designing CMCs. The relevance of studying the effect of oriented fibers on the formation of thermoradiation and temperature fields in a semitransparent material was noted. Modeling the scattering asymmetry coefficient influence (scattering phase function) on the generation of the subsurface thermal radiation source was carried out. The methodology for calculating the thermoradiative field in a semitransparent medium (with relative absorption, scattering indexes, and scattering asymmetry coefficient) was used under a one-dimensional two-flux model as the first approximation for solving the radiative heat transfer equation. Calculations of temperature profiles in opaque and semitransparent ceramics were presented under heat load typical for the combustion chambers operating regime of diesel and gas turbine engines.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47849240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}