Ceramics-Switzerland最新文献

{"title":"Investigation of the Effect of Milling Duration on a Ce-Gd Doped Zirconolite Phase Assemblage Synthesised by Hot Isostatic Pressing","authors":"Merve Kuman, L. J. Gardner, L. R. Blackburn, M. Stennett, N. Hyatt, C. Corkhill","doi":"10.3390/ceramics6010043","DOIUrl":"https://doi.org/10.3390/ceramics6010043","url":null,"abstract":"Zirconolite is a candidate ceramic wasteform under consideration for the immobilisation of the UK civil PuO2 inventory. In the present work, a baseline dual-substituted zirconolite with the target composition (Ca0.783Gd0.017Ce0.2)(Zr0.883Gd0.017Ce0.1)(Ti1.6Al0.4)O7 was fabricated by hot isostatic pressing (HIPing). In order to optimise the microstructure properties and improve the obtained yield of the zirconolite phase, a range of planetary ball milling parameters were investigated prior to consolidation by HIP. This included milling the batched oxide precursors at 400 rpm for up to 120 min, the pre-milling of CeO2 (PuO2 surrogate) to reduce the particle size and using a CeO2 source with finer particle size (<5 µm). The HIPed zirconolite product consisted of both zirconolite-2M and zirconolite-3T polytypes in varying proportions; however, an additional perovskite phase was obtained in varying quantities as a secondary phase. Ce L3-edge X-ray absorption spectroscopy was utilised to determine the Ce oxidation state. In this study, the ideal milling parameter for the fabrication of zirconolite waste forms was defined as 60 min at 400 rpm.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42550716","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 Polymorphic Transformation Processes and Their Influence in Polycrystalline ZrO2 Ceramics upon Irradiation with Heavy Ions","authors":"A. Kozlovskiy, Mahambet Alin, D. Borgekov","doi":"10.3390/ceramics6010042","DOIUrl":"https://doi.org/10.3390/ceramics6010042","url":null,"abstract":"The aim of this work was to study the mechanisms of polymorphic transformations in ZrO2 ceramics under irradiation with heavy ions, as well as to determine the nature of structural distortions in the case of t-ZrO2 → c-ZrO2 type transformations and associated anisotropic deformations. The samples of ZrO2 ceramics were irradiated with Kr15+ heavy ions with an energy of 150 MeV and fluences of 1011–1016 ion/cm2. During evaluation of the structural changes depending on the irradiation fluence, it was found that at low irradiation fluences (1011–1012 ion/cm2), the main role is played by deformation distortions of the crystal lattice, which have a pronounced anisotropic character. Meanwhile, at fluences above 1013 ion/cm2, the main role is played by polymorphic transformations of the t-ZrO2 → c-ZrO2 type, followed by amorphization of the damaged layer at fluences above 1015 ion/cm2. It was established that the anisotropic distortion of the crystal lattice is more pronounced along the crystallographic a axis, as well as the (011) texture orientation, which is characteristic of t-ZrO2. The polymorphic transformation processes of the t-ZrO2 → c-ZrO2 type occur at irradiation fluences of 1013–1014 ions/cm2, which are characterized by the formation of an overlap of local areas of defects that appear along the trajectory of ions in the material. The dependences of changes in the strength and thermophysical properties of ZrO2 ceramics on the irradiation fluence were obtained. The mechanisms of influence of the structural disorder and polymorphic transformations on the decrease in strength and crack resistance were established.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43462908","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":"Process Development of Zirconolite Ceramics for Pu Disposition: Use of a CuO Sintering Aid","authors":"Aidan A. Friskney, Ismail Aldean, C. Corkhill, L. R. Blackburn","doi":"10.3390/ceramics6010041","DOIUrl":"https://doi.org/10.3390/ceramics6010041","url":null,"abstract":"Zirconolite-structured ceramics are candidate wasteform materials for the immobilisation of separated Pu. Due to the refractory properties of zirconolite and other titanates, removing residual porosity remains challenging in the final wasteform product when utilising a conventional solid state sintering route. Herein, we demonstrate that the addition of CuO as a sintering aid increases densification and promotes grain growth. Moreover, zirconolite phase formation was enhanced at lower process temperatures than typically required (≥1350 °C). CuO addition allowed an equivalent density to be reached using process temperatures of 250 °C lower than the undoped composition. At 150 °C lower than the undoped zirconolite, the addition of CuO resulted in a favourable microstructure and phase assemblage, as confirmed via X-ray diffraction and scanning electron microscopy. Secondary phases of CaTiO3 and Ca0.25Cu0.75TiO3 were observed at some processing temperatures, which may prove deleterious to wasteform performance. The use of a CuO sintering aid provides an avenue for the further development of the thermal processing of ceramic wasteform materials.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44010908","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":"Nanoscratch Testing of 3Al2O3·2SiO2 EBCs: Assessment of Induced Damage and Estimation of Adhesion Strength","authors":"C. Botero, L. Cabezas, V. Sarin, L. Llanes, E. Jiménez-Piqué","doi":"10.3390/ceramics6010040","DOIUrl":"https://doi.org/10.3390/ceramics6010040","url":null,"abstract":"In this study, the structural integrity of mullite (3Al2O3·2SiO2) films, deposited on silicon carbide (SiC) substrates using chemical vapor deposition (CVD), was investigated via increasing load nanoscratch tests. The films were configured by mullite columns of stoichiometric composition growing from a silica-rich layer in contact with the SiC substrate. Controlled damage was induced in the 3Al2O3·2SiO2 films at relatively low scratch loads. Radial and lateral cracking were applied until final delamination and repeated chipping were achieved as the load increased. The intrinsic integrity of the 3Al2O3∙2SiO2 film and the performance of the coated 3Al2O3·2SiO2/SiC system, regarded as a structural unit, were analyzed. With the aid of advanced characterization techniques at the surface and subsurface levels, the configuration and morphology of the damage induced in the coated system by the nanoscratch tests were characterized, and the scratch damage micromechanisms were identified. Finally, the adhesion of the film, in terms of energy of adhesion and interfacial fracture toughness, was determined using different models proposed in the literature. The results from this investigation contribute to the understanding of the mechanical performance and structural integrity of EBC/SiC-based systems, which over the past few years have increasingly been implemented in novel applications for gas turbines and aircraft engines.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45372584","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":"Performance of Dental Cements Used for Bonding Zirconia Crowns with Titanium Implants Embedded in an Innovative Bi-Layered Artificial Bone","authors":"M. Satpathy, Hai Pham, Shreya Shah","doi":"10.3390/ceramics6010039","DOIUrl":"https://doi.org/10.3390/ceramics6010039","url":null,"abstract":"This study aimed to investigate four dental adhesive cements and develop a new method for constructing a bi-layered bone holder for implant testing. HahnTM Tapered Titanium Implants (Glidewell Laboratories) were embedded in mono- and bi-layered holders, and the implant components were assembled. First molar zirconia crowns and crowns for the tensile bond strength test were milled and sintered. Three self-adhesive resin cements (SARC) and one resin-modified glass ionomer (RMGI, Glidewell Laboratories) cement were used to cement the crowns on the abutment. Tensile bond strength, compressive load, and oblique load tests were performed on the implants. The Glidewell Experimental SARC (GES, Glidewell Laboratories) and RMGI cements had the highest tensile bond strength after thermocycling. The implant assemblies with these two cements had the highest mean compressive strength after thermocycling. Under oblique load, the implants with Denali (Glidewell Laboratories) and GES had the highest strength before thermocycling. However, after thermocycling, Dencem (Dentex) and RMGI had the highest strength under an oblique load. The GES cement and RMGI cement had a better overall performance with zirconia crowns and titanium abutments. In addition, a novel technique for constructing an artificial, bi-layered bone holder was successfully developed to mimic the natural structure of the jawbone.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-03-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44403317","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":"Potentials of Numerical Methods for Increasing the Productivity of Additive Manufacturing Processes","authors":"U. Scheithauer, Tetyana Romanova, Oleksandr Pankratov, Eric Schwarzer-Fischer, M. Schwentenwein, F. Ertl, A. Fischer","doi":"10.3390/ceramics6010038","DOIUrl":"https://doi.org/10.3390/ceramics6010038","url":null,"abstract":"Thanks to the layer-by-layer creation of components, additive manufacturing (AM) processes enable the flexible production of components with highly complex geometries, that were previously not realizable or only with very great effort. While AM technologies are very widespread in the research sector, they have so far only been used industrially in a few individual areas of application. The manufacturing costs are one reason for this. In this work, a new approach for the optimized arrangement of components in the building box and its potential for reducing the manufacturing costs are presented, illustrated by a selected example, and a discussion. Three types of cylinders, which differ in geometry and/or inclination, are required in quantities of around 1000 each. The optimization aims at an arrangement with the smallest possible number of printing jobs. Compared to the solution obtained by the current automatic software tool that is based on the bounding box method, the optimized arrangement leads to a 70% increase in the number of components on a building platform or, in other words, to a 44% reduction in the number of building platforms needed to manufacture 980 components of each type. Finally, a three-step method is proposed, to optimize the manufacturing preparation for AM components automatically in the future.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45265758","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":"Synthesis and Dielectric Relaxation Studies of KxFeyTi8-yO16 (x = 1.4–1.8 and y = 1.4–1.6) Ceramics with Hollandite Structure","authors":"A. Tsyganov, D. Artyukhov, M. Vikulova, N. Morozova, Ilya Zotov, Sergey Brudnik, Aleksandra Asmolova, Denis Zheleznov, A. Gorokhovsky, N. Gorshkov","doi":"10.3390/ceramics6010037","DOIUrl":"https://doi.org/10.3390/ceramics6010037","url":null,"abstract":"Some solid solutions with the chemical composition KxFeyTi8-yO16 (KFTO) and a hollandite-like structure were successfully synthesized by modified sol–gel method. The obtained powders were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The ceramic pellets based on KFTO powders were obtained by compressing and sintering at 1080 °C for 4 h. The sinters were characterized by X-ray and impedance spectroscopy. XRD results show that KFTO powders have a mono-phase tetragonal structure at x = 1.4–1.8 and y = 1.4–1.6. However, it was recognized that the hollandite-like phase could be broken during sintering to form TiO2 and Fe2TiO5 crystals distributed throughout the volume of the ceramics. A frequency dependency of dielectric properties for the sinters was studied by impedance spectroscopy. It was found that an increase in the TiO2 (rutile) phase during the sintering contributes to a decrease in dielectric losses. At the same time, the KFTO ceramics with reduced content of potassium had increased permittivity. The contribution of electron-pinned defect dipoles (EPDD) and internal barrier layer capacitance (IBLC) in the permittivity of the obtained ceramics was estimated using the Havriliak–Negami equation. It is shown that the KFTO ceramics have the polydisperse characteristic of dielectric relaxation. The observed grain and grain boundary dipole relaxation times were 1.03 × 10−6 to 5.51 × 10−6 s and 0.197 to 0.687 s, respectively.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41929420","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 Materials in Na2O-CaO-P2O5 System, Obtained via Heat Treatment of Cement-Salt Stone Based on Powder Mixture of Ca3(C6H5O7)2 ∙ 4H2O, Ca(H2PO4)2 ∙ H2O and NaH2PO4","authors":"O. Toshev, T. Safronova, T. Shatalova, Yu. S. Lukina","doi":"10.3390/ceramics6010036","DOIUrl":"https://doi.org/10.3390/ceramics6010036","url":null,"abstract":"Ceramic materials in Na2O-CaO-P2O5 system were obtained by firing cement-salt stone made from pastes based on powder mixtures including calcium citrate tetrahydrate Ca3(C6H5O7)2 ∙ 4H2O, monocalcium phosphate monohydrate (MCPM) Ca(H2PO4)2 ∙ H2O and/or sodium dihydrogen phosphate NaH2PO4. The phase composition of the obtained samples of cement-salt stone after adding water, hardening and drying included brushite CaHPO4 ∙ 2H2O, monetite CaHPO4 and also unreacted Ca3(C6H5O7)2 ∙ 4H2O, Ca(H2PO4)2 ∙ H2O and/or NaH2PO4. The phase composition of ceramics in Na2O-CaO-P2O5 system obtained by firing cement-salt stone was formed due to thermal conversion of hydrated salt and heterophase reactions between components presented in samples during firing. The phase composition of ceramic samples based on powder mixture of Ca3(C6H5O7)2 ∙ 4H2O and Ca(H2PO4)2 ∙ H2O after firing at 900 °C included β-calcium pyrophosphate (CPP) β-Ca2P2O7. The phase composition of ceramic samples based on powder mixture of Ca3(C6H5O7)2 ∙ 4H2O, and NaH2PO4 after firing at 900 °C included β-sodium rhenanite β-CaNaPO4. The phase composition of ceramic samples based on powder mixture of Ca3(C6H5O7)2 ∙ 4H2O, Ca(H2PO4)2 ∙H2O and NaH2PO4 after firing at 900 °C included β-Ca2P2O7, β-CaNaPO4, double calcium-sodium pyrophosphate Na2CaP2O7, and Na-substituted tricalcium phosphate Сa10Na(PO4)7. Obtained ceramic materials in Na2O-CaO-P2O5 system including biocompatible and biodegradable phases could be important for treatments of bone tissue defects by means of approaches of regenerative medicine.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45606202","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":"Bucchero Ware from the Etruscan Town of Tarquinia (Italy): A Study of the Production Site and Technology through Spectroscopic Techniques and Multivariate Data Analysis","authors":"Margherita Longoni, Noemi Calore, Matilde Marzullo, Daniele Teseo, Veronica Duranti, G. Bagnasco Gianni, S. Bruni","doi":"10.3390/ceramics6010035","DOIUrl":"https://doi.org/10.3390/ceramics6010035","url":null,"abstract":"Bucchero is a well-known class of Etruscan ceramics, characterized by being entirely black both on the surface and in the body. In the present investigation, a representative set of bucchero sherds from the excavations of the Etruscan town of Tarquinia (Viterbo, Italy) was analyzed through flame atomic absorption spectroscopy (FAAS), Fourier-transform infrared spectroscopy (FTIR) and near-infrared (NIR) reflection spectroscopy. Both elemental and mineralogical composition data were treated with methods of multivariate analysis. It was thus possible to discriminate between local and imported production, to estimate the firing temperature and to verify the origin of the grey-black color in this peculiar ceramic class. Furthermore, a virtual reconstruction of a bucchero vase starting from fragments was also attempted on the basis of chemical analysis data.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42773125","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":"Powders Synthesized from Solutions of Calcium Chloride, Sodium Hydrogen Phosphate, and Sodium Sulfate for Bioceramics Production","authors":"T. Safronova, Alexander S. Khantimirov, T. Shatalova, Y. Filippov, I. Kolesnik, A. Knotko","doi":"10.3390/ceramics6010034","DOIUrl":"https://doi.org/10.3390/ceramics6010034","url":null,"abstract":"Fine powders of brushite CaHPO4·2H2O, ardealite Ca(HPO4)x(SO4)1−x·2H2O (Ca(HPO4)0.5(SO4)0.5·2H2O), and calcium sulfate dihydrate CaSO4·2H2O—all containing sodium chloride NaCl as a reaction by-product—were synthesized from 0.5 M aqueous solution of calcium chloride CaCl2, sodium hydrophosphate Na2HPO4 and/or sodium sulfate Na2SO4. Powder of ardealite Ca(HPO4)x(SO4)1−x·2H2O (Ca(HPO4)0.5(SO4)0.5·2H2O) was synthesized by precipitation from aqueous solution of calcium chloride CaCl2 and mixed-anionic solution simultaneously containing the hydrogen phosphate anion HPO42− (Na2HPO4) and sulfate anion SO42− (Na2SO4). Sodium chloride NaCl, presenting in compacts based on synthesized powders of brushite CaHPO4·2H2O, ardealite Ca(HPO4)x(SO4)1−x·2H2O (Ca(HPO4)0.5(SO4)0.5·2H2O) and calcium sulfate dihydrate CaSO4·2H2O, was responsible for both low-temperature melt formation and the creation of phase composition of ceramics. Heterophase interaction of components led to the resulting phase composition of the ceramic samples during heating, including the formation of chlorapatite Ca5(PO4)3Cl in powders of brushite and ardealite. The phase composition of the ceramics based on the powder of brushite CaHPO4·2H2O containing NaCl as a by-product after firing at 800–1000 °C included β-Ca2P2O7, and Ca5(PO4)3Cl. The phase composition of ceramics based on the powder of ardealite Ca(HPO4)x(SO4)1−x·2H2O (Ca(HPO4)0.5(SO4)0.5·2H2O) containing NaCl as a by-product after firing at 800 and 900 °C included β-Ca2P2O7, CaSO4, and Ca5(PO4)3Cl; after firing at 1000 °C, it includedCaSO4, Ca5(PO4)3Cl and Ca3(PO4)2/Ca10Na(PO4)7, and after firing at 1100 °C, it included CaSO4 and Ca5(PO4)3Cl. The phase composition of ceramics based on powder of calcium sulfate dihydrate CaSO4·2H2O containing NaCl as a by-product after firing at 800–1100 °C included CaSO4 as the predominant phase. The phase composition of all ceramic samples under investigation consisted of biocompatible crystalline phases with different abilities to biodegrade. For this reason, the created ceramics can be recommended for testing as materials for treatment of bone defects using regenerative medicine methods.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":2.8,"publicationDate":"2023-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49167079","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}