Polycrystalline Ta2O5 inverse opal (IO) photonic crystal powders were synthesized using PMMA colloidal crystals as sacrificial templates. We prepared Ta2O5 IO powders with vibrant structural colors at UV–vis wavelengths. The photonic bandgaps (PBGs) in the Ta2O5 IO powders red-shifted as a function of both the macropore diameter and the refractive index of the medium filling the macropores. Owing to their polycrystalline structure, the Ta2O5 IO powders exposed PBGs for various FCC facets, making investigation of their optical properties significantly more complex than Ta2O5 IO thin films that preferentially expose only (111) planes as studied previously. Due to the overlap of the PBGs from different FCC facets and the defects that cause light scattering, much of the typical angle-dependent structural color observed in IO thin films was lost in the Ta2O5 IO powders. This study offers new insights into the optical properties of IO powders.
{"title":"Synthesis of polycrystalline Ta₂O₅ inverse opal photonic crystal powders and their optical characterization","authors":"Taiki Maekawa , Hiroyuki Maekawa , Yuto Ikeda , Tomoya Onoe , Geoffrey I.N. Waterhouse , Kei-ichiro Murai , Toshihiro Moriga","doi":"10.1016/j.oceram.2024.100688","DOIUrl":"10.1016/j.oceram.2024.100688","url":null,"abstract":"<div><div>Polycrystalline Ta<sub>2</sub>O<sub>5</sub> inverse opal (IO) photonic crystal powders were synthesized using PMMA colloidal crystals as sacrificial templates. We prepared Ta<sub>2</sub>O<sub>5</sub> IO powders with vibrant structural colors at UV–vis wavelengths. The photonic bandgaps (PBGs) in the Ta<sub>2</sub>O<sub>5</sub> IO powders red-shifted as a function of both the macropore diameter and the refractive index of the medium filling the macropores. Owing to their polycrystalline structure, the Ta<sub>2</sub>O<sub>5</sub> IO powders exposed PBGs for various FCC facets, making investigation of their optical properties significantly more complex than Ta<sub>2</sub>O<sub>5</sub> IO thin films that preferentially expose only (111) planes as studied previously. Due to the overlap of the PBGs from different FCC facets and the defects that cause light scattering, much of the typical angle-dependent structural color observed in IO thin films was lost in the Ta<sub>2</sub>O<sub>5</sub> IO powders. This study offers new insights into the optical properties of IO powders.</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":"142442208","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 : 2024-09-26DOI: 10.1016/j.oceram.2024.100687
Mohammed Ali M. Rihan , Richard Ocharo Onchiri , Naftary Gathimba , Bernadette Sabuni
Geopolymer or alkali-activated binders are being recognized as an eco-friendly, sustainable substitute for ordinary Portland cement (OPC). The development of high-performance concrete with improved durability and mechanical properties and the addition of environmentally friendly components is a continuous effort. Therefore, the current work examines the durability of fly ash-sugarcane bagasse ash mechanical characteristics in terms of water absorption, exposure to elevated temperatures, and acid resistance. The mechanical properties of the geopolymer concrete (GPC) and OPC concrete specimens were evaluated after being subjected to elevated temperatures of 200 °C, 400 °C, 600 °C, and 800 °C. The acid resistance was determined by submerging the concrete specimens in 3 % sulfuric acid (H2SO4). The acid resistance of the specimens was evaluated through visual inspection, weight variation, and the percentage loss in compressive strength (CR). According to the study, CR typically drops as temperature increases from ambient temperature to 800 °C. However, the rate of decline reduced as temperature increased from ambient temperature to 200 °C. Moreover, the GPC specimens showed a strength loss between 13 % and 21 % following 28 days of sulfuric acid immersion. In contrast, exposure to sulfuric acid caused a 51 % drop in strength for the OPC concrete samples.
{"title":"Assessing the durability performance of geopolymer concrete utilizing fly ash and sugarcane bagasse ash as sustainable binders","authors":"Mohammed Ali M. Rihan , Richard Ocharo Onchiri , Naftary Gathimba , Bernadette Sabuni","doi":"10.1016/j.oceram.2024.100687","DOIUrl":"10.1016/j.oceram.2024.100687","url":null,"abstract":"<div><div>Geopolymer or alkali-activated binders are being recognized as an eco-friendly, sustainable substitute for ordinary Portland cement (OPC). The development of high-performance concrete with improved durability and mechanical properties and the addition of environmentally friendly components is a continuous effort. Therefore, the current work examines the durability of fly ash-sugarcane bagasse ash mechanical characteristics in terms of water absorption, exposure to elevated temperatures, and acid resistance. The mechanical properties of the geopolymer concrete (GPC) and OPC concrete specimens were evaluated after being subjected to elevated temperatures of 200 °C, 400 °C, 600 °C, and 800 °C. The acid resistance was determined by submerging the concrete specimens in 3 % sulfuric acid (H<sub>2</sub>SO<sub>4</sub>). The acid resistance of the specimens was evaluated through visual inspection, weight variation, and the percentage loss in compressive strength (C<sub>R</sub>). According to the study, C<sub>R</sub> typically drops as temperature increases from ambient temperature to 800 °C. However, the rate of decline reduced as temperature increased from ambient temperature to 200 °C. Moreover, the GPC specimens showed a strength loss between 13 % and 21 % following 28 days of sulfuric acid immersion. In contrast, exposure to sulfuric acid caused a 51 % drop in strength for the OPC concrete samples.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357412","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}
In this study, the influence of different additives on a geopolymer matrix composite (GMC) was explored as an alternative to a ceramic matrix composite (CMC) for thermostructural applications. Different GMCs using an N610 textile (10 × 10 cm2) and various additives (SrCO3, BaCO3, BaSO4, MgO and Al2O3 and mullite-rich powder) were cured under 6 MPa at 120 °C for 2 h. The mechanical, microstructural and structural data of the composites were compared with those of the geopolymer matrix after thermal treatment at 1150 °C. The results showed that the addition of alkali-earth barium carbonate or sulfate to the geopolymer matrix facilitated the formation of alkali-earth aluminosilicate crystalline phases and a higher viscous flow apparition temperature (990 °C), which did not enhance its mechanical properties (50 MPa) due to poor impregnation of the textile. Refractory additives such as MgO and Al2O3 in the geopolymer matrix support fiber impregnation with a low-viscous-flow apparition temperature (865 °C) and the formation of crystalline phases such as forsterite, spinel and sapphirine, which act as reinforcements, allowing a flexural strength up to 80 MPa. The addition of a refractory compound, such as mullite, leads to better embedding of fibers and a flexural strength reaching 100 MPa. To conclude, mixing the geopolymer matrix with refractory compounds results in a successful thermo-structural geopolymer composite.
{"title":"Influences of additives on the properties of geopolymer matrix composites (GMCS) for high-temperature applications (1150 °C)","authors":"Quentin Cligny , Ameni Gharzouni , Patrice Duport , Damien Brandt , Sylvie Rossignol","doi":"10.1016/j.oceram.2024.100685","DOIUrl":"10.1016/j.oceram.2024.100685","url":null,"abstract":"<div><div>In this study, the influence of different additives on a geopolymer matrix composite (GMC) was explored as an alternative to a ceramic matrix composite (CMC) for thermostructural applications. Different GMCs using an N610 textile (10 × 10 cm<sup>2</sup>) and various additives (SrCO<sub>3</sub>, BaCO<sub>3</sub>, BaSO<sub>4</sub>, MgO and Al<sub>2</sub>O<sub>3</sub> and mullite-rich powder) were cured under 6 MPa at 120 °C for 2 h. The mechanical, microstructural and structural data of the composites were compared with those of the geopolymer matrix after thermal treatment at 1150 °C. The results showed that the addition of alkali-earth barium carbonate or sulfate to the geopolymer matrix facilitated the formation of alkali-earth aluminosilicate crystalline phases and a higher viscous flow apparition temperature (990 °C), which did not enhance its mechanical properties (50 MPa) due to poor impregnation of the textile. Refractory additives such as MgO and Al<sub>2</sub>O<sub>3</sub> in the geopolymer matrix support fiber impregnation with a low-viscous-flow apparition temperature (865 °C) and the formation of crystalline phases such as forsterite, spinel and sapphirine, which act as reinforcements, allowing a flexural strength up to 80 MPa. The addition of a refractory compound, such as mullite, leads to better embedding of fibers and a flexural strength reaching 100 MPa. To conclude, mixing the geopolymer matrix with refractory compounds results in a successful thermo-structural geopolymer composite.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421928","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 : 2024-09-21DOI: 10.1016/j.oceram.2024.100686
Tim Stötzel , Swantje Funk , Tobias Fey
The presence of pores in a ceramic leads to a lower Young's modulus compared to dense material. For the development of porous ceramics with tailored elastic properties, an exact determination of the Young's modulus is required, especially for industrial applications. Therefore, we investigated the suitability of the non-destructive impulse excitation technique for measuring the dynamic Young's modulus of two-dimensional ceramics with low porosity (P < 19 %). For rectangular samples it was shown that the measurement results depend on the geometric pore position, as added pores outside the nodal lines of the fundamental flexural vibration had no influence on the result. Pores in the inner part of the sample led to a decrease of the Young's modulus that is in good agreement with empirical and analytical models. For the investigated interval of porosity range, the influence of pore size and geometric position on the reduction of the Young's modulus was determined.
{"title":"The sound of porosity: Suitability of the impulse excitation technique (IET) to determine the Young's modulus of 2D macroporous ceramics","authors":"Tim Stötzel , Swantje Funk , Tobias Fey","doi":"10.1016/j.oceram.2024.100686","DOIUrl":"10.1016/j.oceram.2024.100686","url":null,"abstract":"<div><div>The presence of pores in a ceramic leads to a lower Young's modulus compared to dense material. For the development of porous ceramics with tailored elastic properties, an exact determination of the Young's modulus is required, especially for industrial applications. Therefore, we investigated the suitability of the non-destructive impulse excitation technique for measuring the dynamic Young's modulus of two-dimensional ceramics with low porosity (P < 19 %). For rectangular samples it was shown that the measurement results depend on the geometric pore position, as added pores outside the nodal lines of the fundamental flexural vibration had no influence on the result. Pores in the inner part of the sample led to a decrease of the Young's modulus that is in good agreement with empirical and analytical models. For the investigated interval of porosity range, the influence of pore size and geometric position on the reduction of the Young's modulus was determined.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666539524001500/pdfft?md5=949bfb5f0a3940870461e6621efc0076&pid=1-s2.0-S2666539524001500-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142316156","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 : 2024-09-19DOI: 10.1016/j.oceram.2024.100683
Oxel Urra , B. Ferrari , A.J. Sanchez-Herencia , Giorgia Franchin , Paolo Colombo
Progressing towards a sustainable energy model, safer new generation high-performance energy storage devices with large energy density and power are needed. In this sense, the improvement in terms of efficiency and sustainability has led to the interest in solid-state batteries (SSBs). Lately, sodium-ion batteries (SIBs) have become an emerging alternative due to the abundance of raw materials, low cost, and improvements in terms of fast sodium-ion conductor solid electrolytes (SCSEs). Among all the SCSEs, the sodium superionic conductor (NASICON) type electrolyte is one of the most well-known electrolytes, being widely developed in terms of synthesis and materials. However, the processing and manufacturing of these electrolytes have gone almost unnoticed, without considering that well-designed structures of electrodes/electrolytes are the bridge toward turning advanced energy materials into high-performance devices. This work presents the fabrication of 3D complex structures based on NASICON sodium solid electrolytes, obtained for the first time by direct ink writing (DIW). Through a colloidal route, fine NASICON phase powder with high pureness was prepared, enabling the manufacturing of intricate NASICON-printed electrolytes in a one-step fabrication process. By optimizing the ink, a dense electrolyte layer, acting as an ionic conductor and separator, was inserted between two complex porous pattern layers obtaining a device with a total height below 1.15 mm. Further, the densification of the 3D electrolyte was enhanced, reaching high ionic conductivities at room temperature (3.10−4 S cm−1). Thus, a high-performance sodium ion conductor NASICON solid electrolyte with shorter diffusion pathways and larger interfacial surface areas between electrode/electrolyte was obtained, improving the overall electrochemical performance of the device by a 3D layer-by-layer design.
{"title":"Colloidal route towards sodium ionic conductor (NASICON) 3D complex solid electrolyte structures fabricated by direct ink writing (DIW)","authors":"Oxel Urra , B. Ferrari , A.J. Sanchez-Herencia , Giorgia Franchin , Paolo Colombo","doi":"10.1016/j.oceram.2024.100683","DOIUrl":"10.1016/j.oceram.2024.100683","url":null,"abstract":"<div><div>Progressing towards a sustainable energy model, safer new generation high-performance energy storage devices with large energy density and power are needed. In this sense, the improvement in terms of efficiency and sustainability has led to the interest in solid-state batteries (SSBs). Lately, sodium-ion batteries (SIBs) have become an emerging alternative due to the abundance of raw materials, low cost, and improvements in terms of fast sodium-ion conductor solid electrolytes (SCSEs). Among all the SCSEs, the sodium superionic conductor (NASICON) type electrolyte is one of the most well-known electrolytes, being widely developed in terms of synthesis and materials. However, the processing and manufacturing of these electrolytes have gone almost unnoticed, without considering that well-designed structures of electrodes/electrolytes are the bridge toward turning advanced energy materials into high-performance devices. This work presents the fabrication of 3D complex structures based on NASICON sodium solid electrolytes, obtained for the first time by direct ink writing (DIW). Through a colloidal route, fine NASICON phase powder with high pureness was prepared, enabling the manufacturing of intricate NASICON-printed electrolytes in a one-step fabrication process. By optimizing the ink, a dense electrolyte layer, acting as an ionic conductor and separator, was inserted between two complex porous pattern layers obtaining a device with a total height below 1.15 mm. Further, the densification of the 3D electrolyte was enhanced, reaching high ionic conductivities at room temperature (3.10<sup>−4</sup> S cm<sup>−1</sup>). Thus, a high-performance sodium ion conductor NASICON solid electrolyte with shorter diffusion pathways and larger interfacial surface areas between electrode/electrolyte was obtained, improving the overall electrochemical performance of the device by a 3D layer-by-layer design.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666539524001470/pdfft?md5=a6302eca655d69581ed0b7a3ca04f7d7&pid=1-s2.0-S2666539524001470-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312599","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 : 2024-09-19DOI: 10.1016/j.oceram.2024.100684
Rosa Maria da Rocha , Francisco Cristovão Lourenço de Melo , Frank Ferrer Sene , João Marcos Kruszynski de Assis , Miriam Kasumi Hwang Yassuda
The ability to enhance mechanical and oxidation properties for severe environmental applications has led to substantial academic interest in multiphase ultra-high temperature ceramics (UHTC). The purpose of this work is to study the in-situ solid solution formation of (Zr,Ti)B2 from ZrB2 and TiO2 in a ZrB2-SiC composite using hot pressing reaction sintering. For this, a mixture of 10, 20, and 30 % vol% SiC with ZrB2 was mixed with 2.0 wt% TiO2. Hot pressing sintering was performed with a load of 20 MPa at a final temperature of 1850 °C/30 min in an argon atmosphere. The microstructures, crystalline phases, densities, mechanical properties, and oxidation resistance of the composites were examined and compared with ZrB2-SiC samples lacking TiO2. In samples where TiO2 was added, the matrix grain size slightly decreased, the fracture mode was mainly intergranular, and the SiC grain morphology changed the aspect ratio to be more equiaxed. The solid solution (Zr,Ti)B2 was produced, and it was demonstrated by EDS elemental map images and the XRD analysis that Ti atoms incorporate into the ZrB2 crystalline structure. The development of solid solutions showed no impact on relative densities or Vickers hardness. However, the solid solution formation favored an improvement in fracture toughness, probably owing to the smaller matrix grain size and intergranular fracture mode. Samples exhibiting (Zr,Ti)B2 formation presented lower oxidation resistance than undoped samples in the same oxidizing condition.
{"title":"Characterization of (Zr,Ti)B2-SiC composites obtained by hot press sintering of ZrB2-SiC-TiO2 powder mixtures","authors":"Rosa Maria da Rocha , Francisco Cristovão Lourenço de Melo , Frank Ferrer Sene , João Marcos Kruszynski de Assis , Miriam Kasumi Hwang Yassuda","doi":"10.1016/j.oceram.2024.100684","DOIUrl":"10.1016/j.oceram.2024.100684","url":null,"abstract":"<div><div>The ability to enhance mechanical and oxidation properties for severe environmental applications has led to substantial academic interest in multiphase ultra-high temperature ceramics (UHTC). The purpose of this work is to study the in-situ solid solution formation of (Zr,Ti)B<sub>2</sub> from ZrB<sub>2</sub> and TiO<sub>2</sub> in a ZrB<sub>2</sub>-SiC composite using hot pressing reaction sintering. For this, a mixture of 10, 20, and 30 % vol% SiC with ZrB<sub>2</sub> was mixed with 2.0 wt% TiO<sub>2</sub>. Hot pressing sintering was performed with a load of 20 MPa at a final temperature of 1850 °C/30 min in an argon atmosphere. The microstructures, crystalline phases, densities, mechanical properties, and oxidation resistance of the composites were examined and compared with ZrB<sub>2</sub>-SiC samples lacking TiO<sub>2</sub>. In samples where TiO<sub>2</sub> was added, the matrix grain size slightly decreased, the fracture mode was mainly intergranular, and the SiC grain morphology changed the aspect ratio to be more equiaxed. The solid solution (Zr,Ti)B<sub>2</sub> was produced, and it was demonstrated by EDS elemental map images and the XRD analysis that Ti atoms incorporate into the ZrB<sub>2</sub> crystalline structure. The development of solid solutions showed no impact on relative densities or Vickers hardness. However, the solid solution formation favored an improvement in fracture toughness, probably owing to the smaller matrix grain size and intergranular fracture mode. Samples exhibiting (Zr,Ti)B<sub>2</sub> formation presented lower oxidation resistance than undoped samples in the same oxidizing condition.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666539524001482/pdfft?md5=9ab1ee2a0414ae11a8f658ae073b69be&pid=1-s2.0-S2666539524001482-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312600","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 : 2024-09-18DOI: 10.1016/j.oceram.2024.100682
Andrea Volfi , Laura Esposito , Valentina Biasini , Andreana Piancastelli , Jan Hostaša
Transparent ceramics is a unique class of materials, with performance comparable to single crystals, but a high process flexibility given by ceramic technology. Currently, traditional ceramic shaping technologies reliably produce components but are limited in terms of shapes and the use of multiple compositions in a single component. The presented review aims to illustrate how the introduction of additive manufacturing (AM) technology in the production of transparent ceramic components opens new possibilities, both thanks to the high variability of shapes and thanks to the high precision in producing parts with a controlled variation of composition. Within this review, several AM techniques and their current state of the art are analysed, with focus on their advantages in producing transparent ceramics, along with the associated challenges and limitations. The future perspective and possibilities for an industrial production are discussed, with emphasis on the most promising AM techniques, direct ink writing and vat photopolymerisation, pointing out the future scenario for the transparent ceramics market.
透明陶瓷是一类独特的材料，其性能可与单晶体相媲美，但陶瓷技术赋予了其高度的工艺灵活性。目前，传统的陶瓷成型技术可以可靠地生产部件，但在形状和在单个部件中使用多种成分方面受到限制。本综述旨在说明在透明陶瓷部件的生产中引入快速成型（AM）技术是如何开辟新的可能性的，这既得益于形状的高可变性，也得益于在生产部件时对成分变化的高精度控制。在这篇综述中，分析了几种 AM 技术及其当前的技术水平，重点是它们在生产透明陶瓷方面的优势，以及相关的挑战和局限性。文章还讨论了工业化生产的未来前景和可能性，重点是最有前途的 AM 技术、直接墨水写入技术和大桶光聚合技术，并指出了透明陶瓷市场的未来前景。
{"title":"Industrial potential of additive manufacturing of transparent ceramics: A review","authors":"Andrea Volfi , Laura Esposito , Valentina Biasini , Andreana Piancastelli , Jan Hostaša","doi":"10.1016/j.oceram.2024.100682","DOIUrl":"10.1016/j.oceram.2024.100682","url":null,"abstract":"<div><div>Transparent ceramics is a unique class of materials, with performance comparable to single crystals, but a high process flexibility given by ceramic technology. Currently, traditional ceramic shaping technologies reliably produce components but are limited in terms of shapes and the use of multiple compositions in a single component. The presented review aims to illustrate how the introduction of additive manufacturing (AM) technology in the production of transparent ceramic components opens new possibilities, both thanks to the high variability of shapes and thanks to the high precision in producing parts with a controlled variation of composition. Within this review, several AM techniques and their current state of the art are analysed, with focus on their advantages in producing transparent ceramics, along with the associated challenges and limitations. The future perspective and possibilities for an industrial production are discussed, with emphasis on the most promising AM techniques, direct ink writing and vat photopolymerisation, pointing out the future scenario for the transparent ceramics market.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142357413","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}
The relationship between the intrinsic properties of seven different types of fly ash and the compressive strength of the resulting geopolymers was investigated. A comprehensive examination of the effect of chemical and mineralogical compositions, particle size distribution, on the compressive strength of the fly ash-based geopolymers were performed. Results revealed that particle size distribution had a more significant impact on reaction activity than amorphous phase content or average particle size alone. Therefore, a novel concept of 'reaction volume' based on the geopolymerization reaction mechanism was proposed, which reveals a high correlation between the reactivity of fly ash and the compressive strength of geopolymers, thereby enhancing the predictability of the process. The degree of reactivity, formulated through the integration of reaction volume and amorphous silica-aluminum content, was identified as a robust predictor of compressive strength, which can serve as a crucial tool for evaluating fly ash for the production of alkali-activated materials.
{"title":"Innovative assessment of reactivity in fly ash: The role of particle size distribution characteristics","authors":"Rui Gao , Zhangjian Zhou , Jing Yang , Jinquan Zhang","doi":"10.1016/j.oceram.2024.100680","DOIUrl":"10.1016/j.oceram.2024.100680","url":null,"abstract":"<div><div>The relationship between the intrinsic properties of seven different types of fly ash and the compressive strength of the resulting geopolymers was investigated. A comprehensive examination of the effect of chemical and mineralogical compositions, particle size distribution, on the compressive strength of the fly ash-based geopolymers were performed. Results revealed that particle size distribution had a more significant impact on reaction activity than amorphous phase content or average particle size alone. Therefore, a novel concept of 'reaction volume' based on the geopolymerization reaction mechanism was proposed, which reveals a high correlation between the reactivity of fly ash and the compressive strength of geopolymers, thereby enhancing the predictability of the process. The degree of reactivity, formulated through the integration of reaction volume and amorphous silica-aluminum content, was identified as a robust predictor of compressive strength, which can serve as a crucial tool for evaluating fly ash for the production of alkali-activated materials.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666539524001445/pdfft?md5=39c22ce4413049a67538525701dc09c6&pid=1-s2.0-S2666539524001445-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312648","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 : 2024-09-17DOI: 10.1016/j.oceram.2024.100681
Frank Kern, Bettina Osswald
4.4 Ca-TZP was hot pressed in the temperature range between 1200 and 1325 °C for 1 h at 60 MPa pressure. The material was characterized with respect to phase composition, mechanical properties and microstructure. The mechanical properties and phase composition of the Ca-TZP react very sensitively to changes in sintering temperature and average grain size. Fracture toughness continuously increases with sintering temperature from 5 MPa√m to 8.5 MPa√m while bending strength reaches an optimum of 1160 MPa combined with fracture toughness of 5 MPa√m at 1250 °C sintering temperature. The microstructure of the materials is ultrafine. The onset of monoclinic and cubic phase formation is observed at a sintering temperature of 1300 °C and a grain size of ∼140 nm. Indentation at elevated temperature was applied to suppress crack trapping which would lead to extreme overestimation of indentation toughness values.
{"title":"Structure property relations in hot pressed 4.4 mol% calcia stabilized zirconia","authors":"Frank Kern, Bettina Osswald","doi":"10.1016/j.oceram.2024.100681","DOIUrl":"10.1016/j.oceram.2024.100681","url":null,"abstract":"<div><div>4.4 Ca-TZP was hot pressed in the temperature range between 1200 and 1325 °C for 1 h at 60 MPa pressure. The material was characterized with respect to phase composition, mechanical properties and microstructure. The mechanical properties and phase composition of the Ca-TZP react very sensitively to changes in sintering temperature and average grain size. Fracture toughness continuously increases with sintering temperature from 5 MPa√m to 8.5 MPa√m while bending strength reaches an optimum of 1160 MPa combined with fracture toughness of 5 MPa√m at 1250 °C sintering temperature. The microstructure of the materials is ultrafine. The onset of monoclinic and cubic phase formation is observed at a sintering temperature of 1300 °C and a grain size of ∼140 nm. Indentation at elevated temperature was applied to suppress crack trapping which would lead to extreme overestimation of indentation toughness values.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2666539524001457/pdfft?md5=87343c4067854ad2b24f977ea3d3e84f&pid=1-s2.0-S2666539524001457-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142312649","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}
Mg-stabilised Na-β’’-alumina solid electrolyte (Mg-BASE) for Na-ion batteries was synthesised and fabricated into 3D structures via direct ink writing (DIW), an extrusion-based additive manufacturing process. To produce a water-based ink with optimum viscoelastic properties and supreme printing quality, a comprehensive investigation of ink formulation and printing parameters was conducted. The sintered 3D structures of Mg-BASE, fabricated via direct ink writing, achieved relative density of 98.0 ± 1.1 % with β’’ phase fraction of 99.7 wt% whilst bulk ionic conductivity of 0.081 S⋅cm−1 at 350 °C was obtained. XRD results indicated that Mg-BASE fabricated via DIW may have different c-axis orientation than conventional dry-pressed pellets, leading to the improved bulk ionic conductivity.
{"title":"Performance of Mg stabilised Na-β’’-alumina solid electrolytes prepared by direct ink writing","authors":"Dongrui Xie , Athanasios Goulas , Bala Vaidhyanathan , Sina Saremi-Yarahmadi","doi":"10.1016/j.oceram.2024.100674","DOIUrl":"10.1016/j.oceram.2024.100674","url":null,"abstract":"<div><div>Mg-stabilised Na-β’’-alumina solid electrolyte (Mg-BASE) for Na-ion batteries was synthesised and fabricated into 3D structures via direct ink writing (DIW), an extrusion-based additive manufacturing process. To produce a water-based ink with optimum viscoelastic properties and supreme printing quality, a comprehensive investigation of ink formulation and printing parameters was conducted. The sintered 3D structures of Mg-BASE, fabricated via direct ink writing, achieved relative density of 98.0 ± 1.1 % with β’’ phase fraction of 99.7 wt% whilst bulk ionic conductivity of 0.081 S⋅cm<sup>−1</sup> at 350 °C was obtained. XRD results indicated that Mg-BASE fabricated via DIW may have different c-axis orientation than conventional dry-pressed pellets, leading to the improved bulk ionic conductivity.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142421935","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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