Pub Date : 2024-10-21DOI: 10.1016/j.oceram.2024.100698
Cynthia Sin Ting Chang , Marcus Wyss , Michal Andrzejewski , Geoffrey Darut , Lukas Graf , Vladimir Novak , Margie Olbinado , Susanne Erpel , Alexander Vogel , Simon Bode , Michael de Wild , Armando Salito
The microstructure, crystallographic phases, and mechanical properties of a newly developed Al2O3 – TiO2 – ZrO2 ternary ceramic coating were characterized. The coatings were produced by atmospheric plasma spraying as a preblended powder on Ti-6Al-4 V substrates using the new generation of the Debye-Larmor cascaded plasma torch. The 400 μm thick as-sprayed ternary ceramic coating is compact and neither delamination nor inter-/trans-granular cracks were found. The coating consists of single phase α-Al2O3, monoclinic m-ZrO2, and a nanocrystalline dual phase structure of α-Al2O3 and m-ZrO2. Ti is either present as ZrTiO4 or as solute in the dual phase. Cracking from the tip of the indent is rare and delamination was not observed after the progressive scratch test. The coating has potential in high wear applications for example in medical devices.
{"title":"Microstructures, phase and mechanical characterisation of Al2O3-ZrO2-TiO2 coating produced by atmospheric plasma spraying","authors":"Cynthia Sin Ting Chang , Marcus Wyss , Michal Andrzejewski , Geoffrey Darut , Lukas Graf , Vladimir Novak , Margie Olbinado , Susanne Erpel , Alexander Vogel , Simon Bode , Michael de Wild , Armando Salito","doi":"10.1016/j.oceram.2024.100698","DOIUrl":"10.1016/j.oceram.2024.100698","url":null,"abstract":"<div><div>The microstructure, crystallographic phases, and mechanical properties of a newly developed Al<sub>2</sub>O<sub>3</sub> – TiO<sub>2</sub> – ZrO<sub>2</sub> ternary ceramic coating were characterized. The coatings were produced by atmospheric plasma spraying as a preblended powder on Ti-6Al-4 V substrates using the new generation of the Debye-Larmor cascaded plasma torch. The 400 μm thick as-sprayed ternary ceramic coating is compact and neither delamination nor inter-/trans-granular cracks were found. The coating consists of single phase α-Al<sub>2</sub>O<sub>3</sub>, monoclinic m-ZrO<sub>2,</sub> and a nanocrystalline dual phase structure of α-Al<sub>2</sub>O<sub>3</sub> and m-ZrO<sub>2</sub>. Ti is either present as ZrTiO<sub>4</sub> or as solute in the dual phase. Cracking from the tip of the indent is rare and delamination was not observed after the progressive scratch test. The coating has potential in high wear applications for example in medical devices.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-16DOI: 10.1016/j.oceram.2024.100697
Walid Bin Ali, Shintaro Adachi, Fumiko Kimura, Shigeru Horii
In this study, we introduce an original method for quantifying tri-axial magnetic anisotropy in [Ca2CoO3-δ]0.62CoO2, and its rare earth (RE)-doped variants, [(Ca1-xREx)2CoO3-δ]0.62CoO2, utilizing a modulated rotating magnetic field of 10 T. Our findings reveal a significant correlation between the magnetic anisotropy and local structure of RE ions, particularly bond lengths and coordination numbers, which influence the magnetization axes of these magnetically aligned powders. We introduce an analytical methodology employing linear equations to calculate the magnetic susceptibilities along distinct crystallographic axes, enabling the prediction of tri-axial magnetic anisotropies at elevated concentrations of Er ions. This research not only advances our understanding of magnetic anisotropy control but also paves the way for the successful fabrication of triaxially-aligned ceramics using magneto-science techniques.
在本研究中，我们介绍了一种利用 10 T 调制旋转磁场量化[Ca2CoO3-δ]0.62CoO2 及其掺杂稀土 (RE) 的变体[(Ca1-xREx)2CoO3-δ]0.62CoO2 的三轴磁各向异性的独创方法。我们的研究结果表明，磁各向异性与 RE 离子的局部结构（尤其是键长和配位数）之间存在着显著的相关性，而键长和配位数会影响这些磁性排列粉末的磁化轴。我们引入了一种分析方法，利用线性方程计算沿不同结晶轴的磁感应强度，从而能够预测高浓度铒离子的三轴磁各向异性。这项研究不仅加深了我们对磁各向异性控制的理解，还为利用磁科学技术成功制造三轴排列陶瓷铺平了道路。
{"title":"Tri-axial magnetic alignment and magnetic anisotropies in misfit-layered calcium-based cobaltites doped with rare-earth ions","authors":"Walid Bin Ali, Shintaro Adachi, Fumiko Kimura, Shigeru Horii","doi":"10.1016/j.oceram.2024.100697","DOIUrl":"10.1016/j.oceram.2024.100697","url":null,"abstract":"<div><div>In this study, we introduce an original method for quantifying tri-axial magnetic anisotropy in [Ca<sub>2</sub>CoO<sub>3-δ</sub>]<sub>0.62</sub>CoO<sub>2</sub>, and its rare earth (RE)-doped variants, [(Ca<sub>1-<em>x</em></sub>RE<sub><em>x</em></sub>)<sub>2</sub>CoO<sub>3-δ</sub>]<sub>0.62</sub>CoO<sub>2</sub>, utilizing a modulated rotating magnetic field of 10 T. Our findings reveal a significant correlation between the magnetic anisotropy and local structure of RE ions, particularly bond lengths and coordination numbers, which influence the magnetization axes of these magnetically aligned powders. We introduce an analytical methodology employing linear equations to calculate the magnetic susceptibilities along distinct crystallographic axes, enabling the prediction of tri-axial magnetic anisotropies at elevated concentrations of Er ions. This research not only advances our understanding of magnetic anisotropy control but also paves the way for the successful fabrication of triaxially-aligned ceramics using magneto-science techniques.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142531377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-10DOI: 10.1016/j.oceram.2024.100696
Pietro Galizia , Andrea Uccello , Francesco Ghezzi , Luca Labate , Bruno Tiribilli , Ondrej Hanzel , Martina Salvadori , Fernando Brandi , Simone Failla , Cesare Melandri , Anna Cremona , Matteo Pedroni , Marco De Angeli , Enrico Perelli Cippo , Leonida Antonio Gizzi , Peter Tatarko , Diletta Sciti
The thermal properties of ultra-high temperature ceramics (UHTCs) in the MB2-WC (M = Ti, Zr, Hf) system and tungsten were studied for potential application as plasma-facing materials in fusion power plants. The sintered UHTC and tungsten samples were subjected to deuterium plasma or protons irradiation. Thermal diffusivity was measured using the laser flash method, and superficial thermal conductivity was analyzed through atomic force microscopy. Results showed that the thermal properties did not degrade when exposed to relevant environments and remained stable over a range of temperatures, unlike the reference tungsten material. Thermal conductivity ranged from 61 to 68 W m−1 K−1 for TiB2-2(WC-6Co), from 53 to 63 W m−1 K−1 for ZrB2-6WC, from 67 to 75 W m−1 K−1 for HfB2-6WC, and from 180 to 119 W m−1 K−1 for tungsten across the temperature range from room temperature to 1200 °C. The increasing trend of thermal effusivity, over 19000 J s−0.5 m−2 K−1 at 1200 °C, justifies further testing and of UHTC materials for fusion applications.
研究了MB2-WC（M = Ti、Zr、Hf）系超高温陶瓷（UHTC）和钨的热特性，以探讨其作为等离子体面材料应用于核聚变发电厂的可能性。对烧结的超高纯钛和钨样品进行了氘等离子体或质子辐照。使用激光闪光法测量了热扩散率，并通过原子力显微镜分析了表面热导率。结果表明，与参考钨材料不同，热性能在暴露于相关环境时不会退化，并且在一定温度范围内保持稳定。在室温至 1200 °C 的温度范围内，TiB2-2(WC-6Co) 的热导率介于 61 至 68 W m-1 K-1 之间，ZrB2-6WC 的热导率介于 53 至 63 W m-1 K-1 之间，HfB2-6WC 的热导率介于 67 至 75 W m-1 K-1 之间，钨的热导率介于 180 至 119 W m-1 K-1 之间。热效率呈上升趋势，在 1200 ℃ 时超过 19000 J s-0.5 m-2 K-1，这证明有理由对用于聚变应用的超高导热系数材料进行进一步测试。
{"title":"Thermal properties of MB2-WC (M = Ti, Zr, Hf) and tungsten and their stability after deuterium plasma exposure","authors":"Pietro Galizia , Andrea Uccello , Francesco Ghezzi , Luca Labate , Bruno Tiribilli , Ondrej Hanzel , Martina Salvadori , Fernando Brandi , Simone Failla , Cesare Melandri , Anna Cremona , Matteo Pedroni , Marco De Angeli , Enrico Perelli Cippo , Leonida Antonio Gizzi , Peter Tatarko , Diletta Sciti","doi":"10.1016/j.oceram.2024.100696","DOIUrl":"10.1016/j.oceram.2024.100696","url":null,"abstract":"<div><div>The thermal properties of ultra-high temperature ceramics (UHTCs) in the MB<sub>2</sub>-WC (M = Ti, Zr, Hf) system and tungsten were studied for potential application as plasma-facing materials in fusion power plants. The sintered UHTC and tungsten samples were subjected to deuterium plasma or protons irradiation. Thermal diffusivity was measured using the laser flash method, and superficial thermal conductivity was analyzed through atomic force microscopy. Results showed that the thermal properties did not degrade when exposed to relevant environments and remained stable over a range of temperatures, unlike the reference tungsten material. Thermal conductivity ranged from 61 to 68 W m<sup>−1</sup> K<sup>−1</sup> for TiB<sub>2</sub>-2(WC-6Co), from 53 to 63 W m<sup>−1</sup> K<sup>−1</sup> for ZrB<sub>2</sub>-6WC, from 67 to 75 W m<sup>−1</sup> K<sup>−1</sup> for HfB<sub>2</sub>-6WC, and from 180 to 119 W m<sup>−1</sup> K<sup>−1</sup> for tungsten across the temperature range from room temperature to 1200 °C. The increasing trend of thermal effusivity, over 19000 J s<sup>−0.5</sup> m<sup>−2</sup> K<sup>−1</sup> at 1200 °C, justifies further testing and of UHTC materials for fusion applications.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142444847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-10DOI: 10.1016/j.oceram.2024.100695
Oleksandr Vasiliev, Vladyslav Bilyi
Boron carbide (B4C), known for its hardness and low density, is prone to local amorphization under high non-hydrostatic loads, limiting its applications. Aluminum doping is promising due to aluminum's atomic size, fitting into the B4C crystal lattice, particularly the intericosahedra chain, potentially reducing amorphization. This work uses first-principles calculations to study aluminum placement in B4C. We examine the potential for Al substitution in the icosahedron and intericosahedra chain, identifying possible locations. Results show that aluminum can't replace atoms in the icosahedron, but substituting one central atom in the intericosahedra chain with aluminum is energetically favorable and likely changes the chain configuration to an angular one. Additionally, aluminum can substitute one carbon in the (C-B-C) chain of B12(C-B-C) boron carbide. Comparative analysis suggests these configurations may coexist. Our study offers a theoretical model that can guide future experimental efforts and provides valuable insights into the structural specifics of aluminum-doped boron carbide.
{"title":"Specifics of Al substitution into boron carbide: A DFT study","authors":"Oleksandr Vasiliev, Vladyslav Bilyi","doi":"10.1016/j.oceram.2024.100695","DOIUrl":"10.1016/j.oceram.2024.100695","url":null,"abstract":"<div><div>Boron carbide (B<sub>4</sub>C), known for its hardness and low density, is prone to local amorphization under high non-hydrostatic loads, limiting its applications. Aluminum doping is promising due to aluminum's atomic size, fitting into the B<sub>4</sub>C crystal lattice, particularly the intericosahedra chain, potentially reducing amorphization. This work uses first-principles calculations to study aluminum placement in B<sub>4</sub>C. We examine the potential for Al substitution in the icosahedron and intericosahedra chain, identifying possible locations. Results show that aluminum can't replace atoms in the icosahedron, but substituting one central atom in the intericosahedra chain with aluminum is energetically favorable and likely changes the chain configuration to an angular one. Additionally, aluminum can substitute one carbon in the (C-B-C) chain of B<sub>12</sub>(C-B-C) boron carbide. Comparative analysis suggests these configurations may coexist. Our study offers a theoretical model that can guide future experimental efforts and provides valuable insights into the structural specifics of aluminum-doped boron carbide.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-09DOI: 10.1016/j.oceram.2024.100694
Milan Parchovianský , Monika Michálková , Ivana Parchovianská , Beáta Pecušová , Dušan Galusek , Amirhossein Pakseresht
The aim of this study was to explore the effect of different solid phases and varied amounts of polyvinyl alcohol (PVA) on granule size of plasma-sprayable yttria-stabilised zirconia (YSZ) with YSZ whiskers (YSZ/W) and lanthanum cerate (La2Ce2O7, LC) with YSZ whiskers (LC/W) as composite powders. The initial phase of this study involved the preparation and optimization of a YSZ suspension using varying solid loadings of YSZ powder (ranging from 30 to 75 wt%) and PVA serving as both a binder and dispersant. The suspension was subjected to rigorous optimization procedures to meet the required standards. The suspensions were spray dried, and the resulting granulates were examined using SEM to determine their shape and size. The particle size of YSZ granules increased with increasing solid loading of YSZ in the suspension. The optimum amount of dispersant was found to be 1 wt% related to the weight of solid, while the solid loading was 75 wt% of YSZ. In some cases, excessive YSZ solid loading and dispersant impaired the formation of spherical granules. Composite YSZ/W and LC/W granules were also prepared with spherical, lemon, or irregular shapes, with the whiskers embedded in the YSZ or LC powder.
{"title":"Yttria-stabilised zirconia and lanthanum cerate granules with YSZ whiskers prepared by spray drying for thermal barrier coatings","authors":"Milan Parchovianský , Monika Michálková , Ivana Parchovianská , Beáta Pecušová , Dušan Galusek , Amirhossein Pakseresht","doi":"10.1016/j.oceram.2024.100694","DOIUrl":"10.1016/j.oceram.2024.100694","url":null,"abstract":"<div><div>The aim of this study was to explore the effect of different solid phases and varied amounts of polyvinyl alcohol (PVA) on granule size of plasma-sprayable yttria-stabilised zirconia (YSZ) with YSZ whiskers (YSZ/W) and lanthanum cerate (La<sub>2</sub>Ce<sub>2</sub>O<sub>7</sub>, LC) with YSZ whiskers (LC/W) as composite powders. The initial phase of this study involved the preparation and optimization of a YSZ suspension using varying solid loadings of YSZ powder (ranging from 30 to 75 wt%) and PVA serving as both a binder and dispersant. The suspension was subjected to rigorous optimization procedures to meet the required standards. The suspensions were spray dried, and the resulting granulates were examined using SEM to determine their shape and size. The particle size of YSZ granules increased with increasing solid loading of YSZ in the suspension. The optimum amount of dispersant was found to be 1 wt% related to the weight of solid, while the solid loading was 75 wt% of YSZ. In some cases, excessive YSZ solid loading and dispersant impaired the formation of spherical granules. Composite YSZ/W and LC/W granules were also prepared with spherical, lemon, or irregular shapes, with the whiskers embedded in the YSZ or LC powder.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-05DOI: 10.1016/j.oceram.2024.100693
Lenka Ďaková , Alexandra Kovalčíková , Monika Hrubovčáková , Jana Andrejovská , František Kromka , Ján Dusza
Dense (Ti0.2Zr0.2Hf0.2Nb0.2Ta0.2)C with up to 10 wt % SiC whisker were prepared by spark plasma sintering. The influence of SiCw on the microstructure development, mechanical and tribological properties has been investigated. Nanohardness of HEC and SiCw phases varied between 38 GPa and 40 GPa, and indentation modulus of elasticity was ∼605 GPa. The hardness of the composites increased from 22 GPa to 27 GPa and indentation fracture resistance from 3.55 MPa m1/2 to 4.59 MPa m1/2 with increasing SiCw content. The main toughening mechanisms were crack deflection, crack branching, and crack bridging. The system HEC +5 wt% of SiCw was found to possess the highest bending strength of 623 ± 25 MPa. The composites exhibited similar coefficients of frictions with around 0.3 and wear rates approximately 1.50 × 10−6 mm3/N⋅m at 5 N and 2.66 × 10−6 mm3/N⋅m at 25 N with positive influence of SiC phase on the wear mechanisms.
{"title":"Improved mechanical and tribological properties of (TiZrHfNbTa)C with the addition of silicon carbide whiskers","authors":"Lenka Ďaková , Alexandra Kovalčíková , Monika Hrubovčáková , Jana Andrejovská , František Kromka , Ján Dusza","doi":"10.1016/j.oceram.2024.100693","DOIUrl":"10.1016/j.oceram.2024.100693","url":null,"abstract":"<div><div>Dense (Ti<sub>0.2</sub>Zr<sub>0.2</sub>Hf<sub>0.2</sub>Nb<sub>0.2</sub>Ta<sub>0.2</sub>)C with up to 10 wt % SiC whisker were prepared by spark plasma sintering. The influence of SiC<sub>w</sub> on the microstructure development, mechanical and tribological properties has been investigated. Nanohardness of HEC and SiC<sub>w</sub> phases varied between 38 GPa and 40 GPa, and indentation modulus of elasticity was ∼605 GPa. The hardness of the composites increased from 22 GPa to 27 GPa and indentation fracture resistance from 3.55 MPa m<sup>1/2</sup> to 4.59 MPa m<sup>1/2</sup> with increasing SiC<sub>w</sub> content. The main toughening mechanisms were crack deflection, crack branching, and crack bridging. The system HEC +5 wt% of SiC<sub>w</sub> was found to possess the highest bending strength of 623 ± 25 MPa. The composites exhibited similar coefficients of frictions with around 0.3 and wear rates approximately 1.50 × 10<sup>−6</sup> mm<sup>3</sup>/N⋅m at 5 N and 2.66 × 10<sup>−6</sup> mm<sup>3</sup>/N⋅m at 25 N with positive influence of SiC phase on the wear mechanisms.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.oceram.2024.100692
Sonia Marín-Cortés , Mattia Biesuz , Aida Serrano , Emanuele De Bona , Esther Enríquez , José F. Fernández , Vincenzo M. Sglavo
A ceramic composition containing 95 wt% of construction and demolition waste-like material was consolidated by cold sintering process at 200 °C using KOH water solutions as the liquid medium. The relative density of the samples reaches ∼90 % of the theoretical one for process conditions of 600 MPa and 60 min. A post-annealing process at 1100 °C of the as-cold sintered samples causes a slight increase in the relative density and of their mechanical strength compared with conventionally sintered samples at 1100 °C and increases the shape factor of the Weibull distribution, thus increasing the reliability of the component. It is shown that cold sintering of the material avoids its high pyroplasticity, providing low shrinkage and reducing internal defects in the ceramic. This work represents the first exploration of the viability of manufacturing ceramic tiles with high recycled content contributing to the transition to a greener world.
以 KOH 水溶液为液体介质，在 200 °C 下通过冷烧结工艺固结了含有 95% 建筑和拆除废料类材料的陶瓷组合物。在 600 兆帕和 60 分钟的工艺条件下，样品的相对密度达到理论值的 90%。与传统的 1100 °C 烧结样品相比，在 1100 °C 下对冷烧结样品进行后退火处理可使相对密度和机械强度略有增加，并提高威布尔分布的形状系数，从而提高部件的可靠性。研究表明，材料的冷烧结可避免其较高的热塑性，提供较低的收缩率并减少陶瓷的内部缺陷。这项研究首次探索了制造高回收利用率瓷砖的可行性，有助于向绿色世界过渡。
{"title":"Promoting the circularity of ceramic materials through cold sintering of aggregates from construction and demolition waste","authors":"Sonia Marín-Cortés , Mattia Biesuz , Aida Serrano , Emanuele De Bona , Esther Enríquez , José F. Fernández , Vincenzo M. Sglavo","doi":"10.1016/j.oceram.2024.100692","DOIUrl":"10.1016/j.oceram.2024.100692","url":null,"abstract":"<div><div>A ceramic composition containing 95 wt% of construction and demolition waste-like material was consolidated by cold sintering process at 200 °C using KOH water solutions as the liquid medium. The relative density of the samples reaches ∼90 % of the theoretical one for process conditions of 600 MPa and 60 min. A post-annealing process at 1100 °C of the as-cold sintered samples causes a slight increase in the relative density and of their mechanical strength compared with conventionally sintered samples at 1100 °C and increases the shape factor of the Weibull distribution, thus increasing the reliability of the component. It is shown that cold sintering of the material avoids its high pyroplasticity, providing low shrinkage and reducing internal defects in the ceramic. This work represents the first exploration of the viability of manufacturing ceramic tiles with high recycled content contributing to the transition to a greener world.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-02DOI: 10.1016/j.oceram.2024.100691
Md Elias , Ehsanur Rahman , Sonia Akter , Mohammad Awlad Hossain , Rumana A. Jahan , Md Nizam Uddin , Shakhawat H. Firoz
The growing interest in combining the photocatalytic properties of semiconductors like ZnO and TiO2 with the superior electron conduction capabilities of graphene has resulted in the successful synthesis of in-situ reduced graphene oxide (rGO) supported ZnO-TiO2 nanostructures through a simple microwave-assisted synthesis method. X-ray Diffraction Spectroscopy (XRD), Field Emission Scanning Electron Microscope (FESEM), UV–visible spectroscopy (UV–vis), and Fourier Transform Infrared Spectroscopy (FTIR) were employed to characterize structural, morphological and optical properties as well as surface functional groups of the synthesized products. The XRD measurements of our synthesized samples confirm both structural crystallinity and phase purity, while the FTIR analysis verifies the complete reduction of graphene oxide (GO) to reduced graphene oxide (rGO). The synthesized ternary nanocomposite ZnO-TiO2-rGO exhibited a remarkable 100 % adsorption-assisted removal efficiency for 20 mg/L methylene blue (MB) dye under ultraviolet light illumination within 120 min, along with a 56 % dye adsorption removal efficiency in the same time interval. In comparison, pure ZnO showed 0 % adsorption and only 31 % photocatalytic efficiency at the similar condition. Remarkably, the ZnO-TiO2-rGO nanocomposite exhibited exceptional photocatalytic activity mediated by adsorption, achieving complete degradation of MB dye within 5 min under sunlight irradiation. The photocatalytic efficiency and dye adsorption capacity were found to be significantly lower for the anionic dye methyl orange (MO) compared to the cationic MB dye. The study thoroughly investigated the influence of catalyst dose and initial dye concentration on photodegradation. The proposed mechanism indicates that the extensive surface area and numerous active sites on the rGO promote adsorption, which is then followed by degradation through the metal oxides. Overall, the results unveil that the microwave-assisted synthesis of ZnO-TiO2-rGO nanocomposite is a promising and environmentally friendly approach for efficiently degrading dyes from contaminated wastewater using both UV light and natural sunlight irradiation.
{"title":"Eco-friendly fabrication of ZnO-TiO2-rGO nanocomposite for efficient adsorption-assisted organic dyes elimination","authors":"Md Elias , Ehsanur Rahman , Sonia Akter , Mohammad Awlad Hossain , Rumana A. Jahan , Md Nizam Uddin , Shakhawat H. Firoz","doi":"10.1016/j.oceram.2024.100691","DOIUrl":"10.1016/j.oceram.2024.100691","url":null,"abstract":"<div><div>The growing interest in combining the photocatalytic properties of semiconductors like ZnO and TiO<sub>2</sub> with the superior electron conduction capabilities of graphene has resulted in the successful synthesis of in-situ reduced graphene oxide (rGO) supported ZnO-TiO<sub>2</sub> nanostructures through a simple microwave-assisted synthesis method. X-ray Diffraction Spectroscopy (XRD), Field Emission Scanning Electron Microscope (FESEM), UV–visible spectroscopy (UV–vis), and Fourier Transform Infrared Spectroscopy (FTIR) were employed to characterize structural, morphological and optical properties as well as surface functional groups of the synthesized products. The XRD measurements of our synthesized samples confirm both structural crystallinity and phase purity, while the FTIR analysis verifies the complete reduction of graphene oxide (GO) to reduced graphene oxide (rGO). The synthesized ternary nanocomposite ZnO-TiO<sub>2</sub>-rGO exhibited a remarkable 100 % adsorption-assisted removal efficiency for 20 mg/L methylene blue (MB) dye under ultraviolet light illumination within 120 min, along with a 56 % dye adsorption removal efficiency in the same time interval. In comparison, pure ZnO showed 0 % adsorption and only 31 % photocatalytic efficiency at the similar condition. Remarkably, the ZnO-TiO<sub>2</sub>-rGO nanocomposite exhibited exceptional photocatalytic activity mediated by adsorption, achieving complete degradation of MB dye within 5 min under sunlight irradiation. The photocatalytic efficiency and dye adsorption capacity were found to be significantly lower for the anionic dye methyl orange (MO) compared to the cationic MB dye. The study thoroughly investigated the influence of catalyst dose and initial dye concentration on photodegradation. The proposed mechanism indicates that the extensive surface area and numerous active sites on the rGO promote adsorption, which is then followed by degradation through the metal oxides. Overall, the results unveil that the microwave-assisted synthesis of ZnO-TiO<sub>2</sub>-rGO nanocomposite is a promising and environmentally friendly approach for efficiently degrading dyes from contaminated wastewater using both UV light and natural sunlight irradiation.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-30DOI: 10.1016/j.oceram.2024.100690
Francesco Baino , Federico Gaido , Roberta Gabrieli , Dario Alidoost , Alessandro Schiavi , Mehdi Mohammadi , Martin Schwentenwein , Dilshat Tulyaganov , Enrica Verné
The introduction of additive manufacturing technologies in the field of biomaterials science has opened new horizons for regenerative medicine. In this work, we pushed the potential of vat polymerization to the limit for fabricating ultra-porous bioactive SiO2-CaO-MgO-P2O5-CaF2-Na2O glass scaffolds with bone-like architectural characteristics. The tomographic reconstruction of an open-cell foam was used as input file to the printing system and reliably reproduced in all its exquisite details, as assessed by morphological analyses of sintered scaffolds (thickness of single struts 35 μm, exceptionally high porosity around 94 vol%, most pores with size from 500 to 900 μm). Immersion studies in simulated body fluid (SBF) revealed the apatite-forming ability (i.e., in vitro bioactivity) of the scaffolds, the surface of which started being coated by calcium phosphate after just 3 days from the beginning of the experiments. Taken together, these results show great promise for application of such scaffolds in bone defect repair.
{"title":"Vat photopolymerization of ultra-porous bioactive glass foams","authors":"Francesco Baino , Federico Gaido , Roberta Gabrieli , Dario Alidoost , Alessandro Schiavi , Mehdi Mohammadi , Martin Schwentenwein , Dilshat Tulyaganov , Enrica Verné","doi":"10.1016/j.oceram.2024.100690","DOIUrl":"10.1016/j.oceram.2024.100690","url":null,"abstract":"<div><div>The introduction of additive manufacturing technologies in the field of biomaterials science has opened new horizons for regenerative medicine. In this work, we pushed the potential of vat polymerization to the limit for fabricating ultra-porous bioactive SiO<sub>2</sub>-CaO-MgO-P<sub>2</sub>O<sub>5</sub>-CaF<sub>2</sub>-Na<sub>2</sub>O glass scaffolds with bone-like architectural characteristics. The tomographic reconstruction of an open-cell foam was used as input file to the printing system and reliably reproduced in all its exquisite details, as assessed by morphological analyses of sintered scaffolds (thickness of single struts 35 μm, exceptionally high porosity around 94 vol%, most pores with size from 500 to 900 μm). Immersion studies in simulated body fluid (SBF) revealed the apatite-forming ability (i.e., in vitro bioactivity) of the scaffolds, the surface of which started being coated by calcium phosphate after just 3 days from the beginning of the experiments. Taken together, these results show great promise for application of such scaffolds in bone defect repair.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-30DOI: 10.1016/j.oceram.2024.100689
Ahmed Gamal Abd-Elsatar , Hamada Elsayed , Hana Kanková , Branislav Hruška , Jozef Kraxner , Enrico Bernardo , Dušan Galusek
Pharmaceutical containers for parenteral use, including vials, ampoules, prefilled syringes, and cartridges, are traditionally made of glass. However, the most commonly used type, borosilicate glass, is susceptible to issues such as breakage, corrosion, and delamination, which can jeopardize the safety and efficacy of the enclosed drugs. To address these concerns without compromising the visual or qualitative aspects of borosilicate medical glass vials, this study aimed at the enhancement of their mechanical, chemical, and corrosion resistance. A single ion exchange treatment (IET) in a salt bath of molten KNO3 at temperatures of 400, 450, and 500 °C for 2, 12, and 24 h was applied. The effects of the ion exchange process performed under different conditions were assessed by measuring Vickers hardness, crushing load, and chemical durability. The mechanical load required to crush full-body vials after the ion exchange process at 500 °C for 2, 12, and 24 h showed an increase in the applied force values (1650 ± 80, 2340 ± 80, and 2325 ± 40 N) compared to untreated vials (1157 ± 20 N).
No radial cracks were observed on the surface of treated glass vials after indentation, indicating the presence of compressive stresses that prevented the initiation and propagation of cracks. The EDS analysis confirmed an increase in potassium concentration and a decrease in sodium content near the surface of samples modified by ion exchange treatment. The treated samples showed appropriate chemical stability in different acidic, basic, and neutral solutions. Conspicuous changes are noticed in the Raman spectra after IET, specifically in the Qn species region. The results indicate the potential of the ion exchange treatment in enhancing the properties of borosilicate glass vials by relatively simple and easily scalable techniques.
{"title":"Ion-exchange enhancement of borosilicate glass vials for pharmaceutical packaging","authors":"Ahmed Gamal Abd-Elsatar , Hamada Elsayed , Hana Kanková , Branislav Hruška , Jozef Kraxner , Enrico Bernardo , Dušan Galusek","doi":"10.1016/j.oceram.2024.100689","DOIUrl":"10.1016/j.oceram.2024.100689","url":null,"abstract":"<div><div>Pharmaceutical containers for parenteral use, including vials, ampoules, prefilled syringes, and cartridges, are traditionally made of glass. However, the most commonly used type, borosilicate glass, is susceptible to issues such as breakage, corrosion, and delamination, which can jeopardize the safety and efficacy of the enclosed drugs. To address these concerns without compromising the visual or qualitative aspects of borosilicate medical glass vials, this study aimed at the enhancement of their mechanical, chemical, and corrosion resistance. A single ion exchange treatment (IET) in a salt bath of molten KNO<sub>3</sub> at temperatures of 400, 450, and 500 °C for 2, 12, and 24 h was applied. The effects of the ion exchange process performed under different conditions were assessed by measuring Vickers hardness, crushing load, and chemical durability. The mechanical load required to crush full-body vials after the ion exchange process at 500 °C for 2, 12, and 24 h showed an increase in the applied force values (1650 ± 80, 2340 ± 80, and 2325 ± 40 N) compared to untreated vials (1157 ± 20 N).</div><div>No radial cracks were observed on the surface of treated glass vials after indentation, indicating the presence of compressive stresses that prevented the initiation and propagation of cracks. The EDS analysis confirmed an increase in potassium concentration and a decrease in sodium content near the surface of samples modified by ion exchange treatment. The treated samples showed appropriate chemical stability in different acidic, basic, and neutral solutions. Conspicuous changes are noticed in the Raman spectra after IET, specifically in the Q<sub>n</sub> species region. The results indicate the potential of the ion exchange treatment in enhancing the properties of borosilicate glass vials by relatively simple and easily scalable techniques.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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