Pub Date : 2024-12-01DOI: 10.1016/j.oceram.2024.100713
N.M.P. Truong , M. Michálková , M. Sedano , M.J. Pascual , R. Klement
Glasses of compositions 40SiO2-25Al2O3-18Li2O-7LiF-(10-x-y)YF3-xErF3-yYbF3 (mol.%, x = 0.1, 0.5; y = 0, 0.4, 2, 4) were prepared by melt-quenching technique and milled into powders. Glass powder pellets were treated by hot pressing at defined temperatures to obtain the corresponding glass-ceramics (GCs). High-resolution TEM and XRD analysis revealed the crystallization of LiYF4 and LiAlSiO4 phases with nano-crystal size below 50 nm, resulting in translucent GCs. The density of GCs was 98–99.5 % compared to parent glasses. GCs exhibited intense up-conversion emission when excited by near-infrared light at 980 nm. As Er3+ concentration increased from 0.1 to 0.5 mol.% in the samples, notable enhancement in green and red emission intensities was indicated. Yb3+ ions significantly facilitated up-conversion emission through energy transfer to Er3+ ions, resulting in a higher luminescence yield compared to Er3+ single-doped GCs. The tuning of the red to green emission intensity ratio can be achieved by varying Er3+ and Yb3+ concentrations and Er3+/Yb3+ ratio.
{"title":"Pressure-assisted sintering approaches for up-converting LiYF4:Er/Yb transparent oxyfluoride glass-ceramics","authors":"N.M.P. Truong , M. Michálková , M. Sedano , M.J. Pascual , R. Klement","doi":"10.1016/j.oceram.2024.100713","DOIUrl":"10.1016/j.oceram.2024.100713","url":null,"abstract":"<div><div>Glasses of compositions 40SiO<sub>2</sub>-25Al<sub>2</sub>O<sub>3</sub>-18Li<sub>2</sub>O-7LiF-(10-x-y)YF<sub>3</sub>-xErF<sub>3</sub>-yYbF<sub>3</sub> (mol.%, <em>x</em> = 0.1, 0.5; <em>y</em> = 0, 0.4, 2, 4) were prepared by melt-quenching technique and milled into powders. Glass powder pellets were treated by hot pressing at defined temperatures to obtain the corresponding glass-ceramics (GCs). High-resolution TEM and XRD analysis revealed the crystallization of LiYF<sub>4</sub> and LiAlSiO<sub>4</sub> phases with nano-crystal size below 50 nm, resulting in translucent GCs. The density of GCs was 98–99.5 % compared to parent glasses. GCs exhibited intense up-conversion emission when excited by near-infrared light at 980 nm. As Er<sup>3+</sup> concentration increased from 0.1 to 0.5 mol.% in the samples, notable enhancement in green and red emission intensities was indicated. Yb<sup>3+</sup> ions significantly facilitated up-conversion emission through energy transfer to Er<sup>3+</sup> ions, resulting in a higher luminescence yield compared to Er<sup>3+</sup> single-doped GCs. The tuning of the red to green emission intensity ratio can be achieved by varying Er<sup>3+</sup> and Yb<sup>3+</sup> concentrations and Er<sup>3+</sup>/Yb<sup>3+</sup> ratio.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":"20 ","pages":"Article 100713"},"PeriodicalIF":2.9,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142746868","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 : 2024-11-19DOI: 10.1016/j.oceram.2024.100711
Muthukumar Abishek , Marija Prekajski Đorđević , Svetlana Butulija , Branko Matović , Ravi Kumar
Two compositionally complex oxides (CCOs) of the type (Hf0.2Zr0.2Ce0.2Gd0.2 RE0.2)O2-δ, were synthesized via self-propagating room temperature synthesis where RE=Yb for one of the two, while in the other case, Yb was replaced by equal concentrations of Pr and Nd. Heat-treatment at varied temperatures between 900 °C – 1500 °C and phase evolution studies revealed the formation of a single phase with a FCC structure with the Yb containing oxide. However, the substitution of Yb with Pr and Nd resulted in an additional secondary FCC phase. Furthermore, Raman spectroscopy confirmed pyrochlore-type ordering in both compounds with exemplification of superlattice planes in high-resolution transmission electron microscopic images. The presence of 3+ and 4+ cations confirmed by X-ray photoelectron spectroscopy, is in accordance with the results on the pyrochlore structure containing two different cationic species.
{"title":"Self-propagating room temperature synthesis and structural characterization of transition metal-rare earth based compositionally complex oxides","authors":"Muthukumar Abishek , Marija Prekajski Đorđević , Svetlana Butulija , Branko Matović , Ravi Kumar","doi":"10.1016/j.oceram.2024.100711","DOIUrl":"10.1016/j.oceram.2024.100711","url":null,"abstract":"<div><div>Two compositionally complex oxides (CCOs) of the type (Hf<sub>0.2</sub>Zr<sub>0.2</sub>Ce<sub>0.2</sub>Gd<sub>0.2</sub> RE<sub>0.2</sub>)O<sub>2-δ,</sub> were synthesized via self-propagating room temperature synthesis where RE=Yb for one of the two, while in the other case, Yb was replaced by equal concentrations of Pr and Nd. Heat-treatment at varied temperatures between 900 °C – 1500 °C and phase evolution studies revealed the formation of a single phase with a FCC structure with the Yb containing oxide. However, the substitution of Yb with Pr and Nd resulted in an additional secondary FCC phase. Furthermore, Raman spectroscopy confirmed pyrochlore-type ordering in both compounds with exemplification of superlattice planes in high-resolution transmission electron microscopic images. The presence of 3+ and 4+ cations confirmed by X-ray photoelectron spectroscopy, is in accordance with the results on the pyrochlore structure containing two different cationic species.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":"20 ","pages":"Article 100711"},"PeriodicalIF":2.9,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702162","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 : 2024-11-19DOI: 10.1016/j.oceram.2024.100705
Johannes Schubert , Pascal Friederich , Benedikt Burchard , Frederik Zanger
Additive manufacturing by vat photopolymerization (VPP) enables the flexible production of ceramic components. The process requires ceramic slurries consisting of a photosensitive binder system and ceramic powder. To prevent defects during debinding and sintering, the highest possible content of ceramic particles is desired. At the same time, a certain viscosity must not be exceeded to ensure the processability in the VPP process. This conflict of objectives requires a precise adjustment of the large amount of slurry constituents. Hence, an experimental slurry development and optimization is very expensive and time-consuming. Therefore, Bayesian optimization, an artificial intelligence (AI) approach, was used to enhance an experimental optimization of the slurry composition. Using this approach, it was possible to achieve in less than 40 optimization steps an aluminum oxide (Al2O3) slurry suitable for VPP with a content of 65 vol.% ceramic powder, the highest currently known fraction for Al2O3 in VPP slurries.
{"title":"Development of aluminum oxide slurries for additive manufacturing by Bayesian optimization","authors":"Johannes Schubert , Pascal Friederich , Benedikt Burchard , Frederik Zanger","doi":"10.1016/j.oceram.2024.100705","DOIUrl":"10.1016/j.oceram.2024.100705","url":null,"abstract":"<div><div>Additive manufacturing by vat photopolymerization (VPP) enables the flexible production of ceramic components. The process requires ceramic slurries consisting of a photosensitive binder system and ceramic powder. To prevent defects during debinding and sintering, the highest possible content of ceramic particles is desired. At the same time, a certain viscosity must not be exceeded to ensure the processability in the VPP process. This conflict of objectives requires a precise adjustment of the large amount of slurry constituents. Hence, an experimental slurry development and optimization is very expensive and time-consuming. Therefore, Bayesian optimization, an artificial intelligence (AI) approach, was used to enhance an experimental optimization of the slurry composition. Using this approach, it was possible to achieve in less than 40 optimization steps an aluminum oxide (Al<sub>2</sub>O<sub>3</sub>) slurry suitable for VPP with a content of 65 vol.% ceramic powder, the highest currently known fraction for Al<sub>2</sub>O<sub>3</sub> in VPP slurries.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":"20 ","pages":"Article 100705"},"PeriodicalIF":2.9,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702161","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 : 2024-11-19DOI: 10.1016/j.oceram.2024.100706
Jessica Lippert, Marcela Arango-Ospina, Aldo R. Boccaccini
Bioactive glasses (BGs) are highly researched biomaterials in the field of bone tissue engineering. Besides their good biocompatibility and biodegradability, they also develop osteogenic and angiogenic effects due to the release of several biologically active ions through the dissolution process. To further improve the functionality of BGs, different biomolecules can be added, which are then released into the body together with the BG ionic dissolution products. For this purpose, phytotherapeutic agents can be used, which have the potential advantage of inducing less undesirable side effects than synthetic drugs and can exhibit anti-inflammatory and antibacterial activity. A well-known example of such natural compounds is the Manuka honey from New Zealand, which was used in this project. The aim of this study was thus to investigate the synergistic effects of the dissolution products of bioactive glasses in combination with Manuka honey (MH). Different relevant bioactive glass compositions (45S5 BG, 13–93 BG and 0106-B1 BG) were combined with MH. Cell biology (osteoblast-like cell line MG-63) and antibacterial assays (E. coli and S. aureus) were performed. The results indicated synergistic effects of BGs and MH, particularly in relation to the antibacterial activity of BG-MH combinations, which resulted in overall bacteria viabilities of < 40% compared to 80% of viable bacteria for BG samples without MH. Interestingly, the ionic dissolution products from 13-93 BG and 0106-B1 BG showed superior effects on MG-63 cells when combined with MH compared with 45S5 BG at the same concentrations. These findings suggest that combining BGs with MH enhances the stimulatory effects on cells and bacteria, supporting the potential use of BGs in combination with natural compounds for tissue engineering applications.
{"title":"Study of the synergistic effects of bioactive glasses with Manuka honey","authors":"Jessica Lippert, Marcela Arango-Ospina, Aldo R. Boccaccini","doi":"10.1016/j.oceram.2024.100706","DOIUrl":"10.1016/j.oceram.2024.100706","url":null,"abstract":"<div><div>Bioactive glasses (BGs) are highly researched biomaterials in the field of bone tissue engineering. Besides their good biocompatibility and biodegradability, they also develop osteogenic and angiogenic effects due to the release of several biologically active ions through the dissolution process. To further improve the functionality of BGs, different biomolecules can be added, which are then released into the body together with the BG ionic dissolution products. For this purpose, phytotherapeutic agents can be used, which have the potential advantage of inducing less undesirable side effects than synthetic drugs and can exhibit anti-inflammatory and antibacterial activity. A well-known example of such natural compounds is the Manuka honey from New Zealand, which was used in this project. The aim of this study was thus to investigate the synergistic effects of the dissolution products of bioactive glasses in combination with Manuka honey (MH). Different relevant bioactive glass compositions (45S5 BG, 13–93 BG and 0106-B1 BG) were combined with MH. Cell biology (osteoblast-like cell line MG-63) and antibacterial assays (<em>E. coli</em> and <em>S. aureus</em>) were performed. The results indicated synergistic effects of BGs and MH, particularly in relation to the antibacterial activity of BG-MH combinations, which resulted in overall bacteria viabilities of < 40% compared to 80% of viable bacteria for BG samples without MH. Interestingly, the ionic dissolution products from 13-93 BG and 0106-B1 BG showed superior effects on MG-63 cells when combined with MH compared with 45S5 BG at the same concentrations. These findings suggest that combining BGs with MH enhances the stimulatory effects on cells and bacteria, supporting the potential use of BGs in combination with natural compounds for tissue engineering applications.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":"21 ","pages":"Article 100706"},"PeriodicalIF":2.9,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747749","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 : 2024-11-17DOI: 10.1016/j.oceram.2024.100709
Durgaprasad D. Ramteke , Miroslava Hujova , Jozef Kraxner , Dusan Galusek , Hamada Elsayed , Paolo Colombo , Enrico Bernardo
Discarded soda-lime glass (SLG) may contain small amounts of ceramic, metallic, and polymeric contaminants, therefore recycling of this material is far from ideal. The quality of newly made glass products made by remelting of cullet, as a result, declines. Consolidation at low temperatures to form materials similar to geopolymers could enable the complete re-use of contaminated cullet. SLG powders, either as received or after pre-washing in an acid solution, were added to a sodium aluminate solution and mechanically stirred at a low speed for three hours at room temperature. The formation of microporous semi-crystalline monoliths involved suspensions casting into plastic molds, followed by an overnight cure at 75 °C. The monoliths prepared from both untreated SLG particles and pre-washed SLG particles contained crystalline phases of zeolite LTA and hydrosodalite. The mechanical characteristics showed good agreement with the properties of cementitious materials, with compressive strength ranging from 22 to 29 MPa and flexural strength ranging from 13.2 to 19.9 MPa. Furthermore, the technique effectively produced Venetian terrazzo-like samples by adding coarse glass particles as fillers with particle sizes of up to 3 mm, which could lead to significant material and energy savings in their fabrication. The suggested method could be expanded to include other challenging-to-reuse glass formulations, providing attractive and versatile recycled materials.
{"title":"Attack of discarded soda-lime glass with sodium aluminate for the manufacturing of sustainable geopolymer components","authors":"Durgaprasad D. Ramteke , Miroslava Hujova , Jozef Kraxner , Dusan Galusek , Hamada Elsayed , Paolo Colombo , Enrico Bernardo","doi":"10.1016/j.oceram.2024.100709","DOIUrl":"10.1016/j.oceram.2024.100709","url":null,"abstract":"<div><div>Discarded soda-lime glass (SLG) may contain small amounts of ceramic, metallic, and polymeric contaminants, therefore recycling of this material is far from ideal. The quality of newly made glass products made by remelting of cullet, as a result, declines. Consolidation at low temperatures to form materials similar to geopolymers could enable the complete re-use of contaminated cullet. SLG powders, either as received or after pre-washing in an acid solution, were added to a sodium aluminate solution and mechanically stirred at a low speed for three hours at room temperature. The formation of microporous semi-crystalline monoliths involved suspensions casting into plastic molds, followed by an overnight cure at 75 °C. The monoliths prepared from both untreated SLG particles and pre-washed SLG particles contained crystalline phases of zeolite LTA and hydrosodalite. The mechanical characteristics showed good agreement with the properties of cementitious materials, with compressive strength ranging from 22 to 29 MPa and flexural strength ranging from 13.2 to 19.9 MPa. Furthermore, the technique effectively produced Venetian terrazzo-like samples by adding coarse glass particles as fillers with particle sizes of up to 3 mm, which could lead to significant material and energy savings in their fabrication. The suggested method could be expanded to include other challenging-to-reuse glass formulations, providing attractive and versatile recycled materials.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":"20 ","pages":"Article 100709"},"PeriodicalIF":2.9,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702163","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}
A new group of boro-tellurite glasses (BCa20, BCa17, BCa14, BCa11) was fabricated using the melt quench method for potential radiation shielding and optical applications. The mechanical, optical, and radiation shielding properties were studied with varying oxide compositions. A decrease in B2O3 and CaO content, with increasing TeO2, led to a reduction in elastic modulus and bulk modulus (from 69.638 to 61.331 GPa), as well as a decrease in packing density (0.673 to 0.636). The optical band gap also gradually reduced (from 3.637 to 3.504 eV), while Urbach energy increased (from 0.293 to 0.354 eV). Optical basicity increased, and optical electronegativity decreased, indicating a shift toward ionic bonding and reduced glass stability. Radiation shielding performance improved with the addition of TeO2, as confirmed by the linear attenuation coefficient (LAC) results using Phy-X software. These findings suggest potential for these glasses in radiation shielding and optical material applications.
{"title":"Development of and study of boro-tellurite glasses for optical and radiation shielding applications","authors":"M.I. Sayyed , M.H.A. Mhareb , Heryanto heryanto , Yasser Maghrbi","doi":"10.1016/j.oceram.2024.100708","DOIUrl":"10.1016/j.oceram.2024.100708","url":null,"abstract":"<div><div>A new group of boro-tellurite glasses (BCa20, BCa17, BCa14, BCa11) was fabricated using the melt quench method for potential radiation shielding and optical applications. The mechanical, optical, and radiation shielding properties were studied with varying oxide compositions. A decrease in B<sub>2</sub>O<sub>3</sub> and CaO content, with increasing TeO<sub>2</sub>, led to a reduction in elastic modulus and bulk modulus (from 69.638 to 61.331 GPa), as well as a decrease in packing density (0.673 to 0.636). The optical band gap also gradually reduced (from 3.637 to 3.504 eV), while Urbach energy increased (from 0.293 to 0.354 eV). Optical basicity increased, and optical electronegativity decreased, indicating a shift toward ionic bonding and reduced glass stability. Radiation shielding performance improved with the addition of TeO<sub>2</sub>, as confirmed by the linear attenuation coefficient (LAC) results using Phy-X software. These findings suggest potential for these glasses in radiation shielding and optical material applications.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":"20 ","pages":"Article 100708"},"PeriodicalIF":2.9,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702159","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 : 2024-11-14DOI: 10.1016/j.oceram.2024.100707
Michael W. Mervosh , Sevag Momjian , Javier Mena-Garcia , Clive A. Randall
Conventional varistors rely on the formation of a Double Schottky Barrier within the intergranular region of ZnO via acceptor doping and a Bi2O3 phase. This work has been able to yield varistor-like behavior via cold sintered ZnO composites by placing 2D hBN flakes on the grain boundaries within the ZnO matrix. Above the percolation threshold, a network of resistive hBN barriers is formed which prevents current from flowing through the more conductive ZnO. However, at a given voltage, electrons can tunnel through the hBN if the layers are kept thin enough. Within this narrow band of hBN content, samples have been fabricated with α values as high as 9.5. The composite system demonstrated Schottky conduction at low fields before switching to Fowler-Nordheim tunneling at high fields. This microstructural design was able to show greater nonlinearity compared to previous attempts at creating varistor materials through the unique cold sintering process (CSP).
{"title":"Using percolation to design ZnO composites with hBN modified grain boundaries to obtain varistor-like behavior","authors":"Michael W. Mervosh , Sevag Momjian , Javier Mena-Garcia , Clive A. Randall","doi":"10.1016/j.oceram.2024.100707","DOIUrl":"10.1016/j.oceram.2024.100707","url":null,"abstract":"<div><div>Conventional varistors rely on the formation of a Double Schottky Barrier within the intergranular region of ZnO via acceptor doping and a Bi<sub>2</sub>O<sub>3</sub> phase. This work has been able to yield varistor-like behavior via cold sintered ZnO composites by placing 2D hBN flakes on the grain boundaries within the ZnO matrix. Above the percolation threshold, a network of resistive hBN barriers is formed which prevents current from flowing through the more conductive ZnO. However, at a given voltage, electrons can tunnel through the hBN if the layers are kept thin enough. Within this narrow band of hBN content, samples have been fabricated with α values as high as 9.5. The composite system demonstrated Schottky conduction at low fields before switching to Fowler-Nordheim tunneling at high fields. This microstructural design was able to show greater nonlinearity compared to previous attempts at creating varistor materials through the unique cold sintering process (CSP).</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":"20 ","pages":"Article 100707"},"PeriodicalIF":2.9,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702157","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 : 2024-11-13DOI: 10.1016/j.oceram.2024.100702
Jinping Cui, Kang Guan, Pinggen Rao
Comprehensive research on crack propagation in SiCf/SiC composites is essential for understanding fracture mechanisms, enhancing toughening capabilities, extending service life in engineering applications, and driving new methodologies and theories in strength design. Despite their importance, the defect sensitivity and crack propagation resistance (CPR) of SiCf/SiC composites remain underexplored, with the influence of component parameters on CPR still unclear. Herein, we develop a novel approach and propose a new three-dimensional finite element model that incorporates varying interface layer thicknesses and randomly distributed fibers, using the single-edged pre-crack beam method. By introducing the critical strain parameter, the model quantitatively evaluates fracture energy and the effects of mesoscopic components on CPR. Our findings provide valuable insights into optimizing the mesoscopic components for enhanced toughness in SiCf/SiC composites.
{"title":"Critical strain as a metric for crack propagation resistance in SiCf/SiC composites","authors":"Jinping Cui, Kang Guan, Pinggen Rao","doi":"10.1016/j.oceram.2024.100702","DOIUrl":"10.1016/j.oceram.2024.100702","url":null,"abstract":"<div><div>Comprehensive research on crack propagation in SiC<sub>f</sub>/SiC composites is essential for understanding fracture mechanisms, enhancing toughening capabilities, extending service life in engineering applications, and driving new methodologies and theories in strength design. Despite their importance, the defect sensitivity and crack propagation resistance (CPR) of SiC<sub>f</sub>/SiC composites remain underexplored, with the influence of component parameters on CPR still unclear. Herein, we develop a novel approach and propose a new three-dimensional finite element model that incorporates varying interface layer thicknesses and randomly distributed fibers, using the single-edged pre-crack beam method. By introducing the critical strain parameter, the model quantitatively evaluates fracture energy and the effects of mesoscopic components on CPR. Our findings provide valuable insights into optimizing the mesoscopic components for enhanced toughness in SiC<sub>f</sub>/SiC composites.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":"20 ","pages":"Article 100702"},"PeriodicalIF":2.9,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702156","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 : 2024-11-13DOI: 10.1016/j.oceram.2024.100704
Mursaleen Shahid, Vincenzo M. Sglavo
Quick setting cement-based materials were produced in the present work using the binder jetting 3D printing (BJ3DP) technique with the aim at investigating how processing parameters like water-to-cement ratio and aggregate size affect the final properties of the products. Commercially available quick-setting cement and siliceous sand were utilized. Dimensional accuracy, compressive and flexural strength were measured for variable processing conditions and their individual effect was analysed. The results showed that the properties of printed parts are significantly influenced by the considered processing variables and, in particular, a larger water-to-cement ratio has a beneficial effect on the mechanical performances, the improvement being higher when coarser siliceous sand is used. It was also shown that the employment of finer sand results in more limited dimensional accuracy.
{"title":"Effect of water-to-quick setting cement ratio and aggregate size on mechanical properties and dimensional accuracy of binder jetting 3D-printed bodies","authors":"Mursaleen Shahid, Vincenzo M. Sglavo","doi":"10.1016/j.oceram.2024.100704","DOIUrl":"10.1016/j.oceram.2024.100704","url":null,"abstract":"<div><div>Quick setting cement-based materials were produced in the present work using the binder jetting 3D printing (BJ3DP) technique with the aim at investigating how processing parameters like water-to-cement ratio and aggregate size affect the final properties of the products. Commercially available quick-setting cement and siliceous sand were utilized. Dimensional accuracy, compressive and flexural strength were measured for variable processing conditions and their individual effect was analysed. The results showed that the properties of printed parts are significantly influenced by the considered processing variables and, in particular, a larger water-to-cement ratio has a beneficial effect on the mechanical performances, the improvement being higher when coarser siliceous sand is used. It was also shown that the employment of finer sand results in more limited dimensional accuracy.</div></div>","PeriodicalId":34140,"journal":{"name":"Open Ceramics","volume":"20 ","pages":"Article 100704"},"PeriodicalIF":2.9,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657431","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 : 2024-11-08DOI: 10.1016/j.oceram.2024.100700
Yan Wang , Zhihe Xiao , Jian Gu , Weibin Sun , Junyang Jin , Xin Sun
With aim to prepare nano-microwave absorption material with excellent microwave absorption performance, core-shell structured C@TiC nanocomposites with tunable nanostructures and morphologies were successfully synthesized through one-step pyrolysis of the Ti-based MOFs precursors at a low temperature. Effects of various metal/linker ratio, solvent types and Hacac addition on the microstructures and properties of the C@TiC nanocomposites were thoroughly investigated, demonstrating that the TiC core-C shell structure could be effectively tailored. Compared to pure TiC nanoparticles, the C@TiC nanocomposites exhibited significantly improved microwave absorption performance, including the stronger RL peak of -35.64 dB (10.72 GHz) at 2.4 mm thicknesses and the enhanced effective microwave wave absorption width (EAB, RL≤-10 dB) spanning the entire C-band and X-band, which is ascribed to the better impedance matching and richer microwave loss mechanisms. As a result, C@TiC nanocomposites show great potential to be applied as absorbers with strong microwave absorption and wide absorption bandwidth.
为了制备具有优异微波吸收性能的纳米微波吸收材料，通过在低温下一步热解钛基MOFs前驱体，成功合成了具有可调纳米结构和形态的核壳结构C@TiC纳米复合材料。深入研究了不同金属/连接体比例、溶剂类型和 Hacac 添加量对 C@TiC 纳米复合材料微观结构和性能的影响，结果表明 TiC 核-壳结构可有效定制。与纯 TiC 纳米颗粒相比，C@TiC 纳米复合材料的微波吸收性能得到了显著改善，包括在厚度为 2.4 mm 时具有更强的 RL 峰值 -35.64 dB（10.72 GHz），有效微波吸收宽度（EAB，RL≤-10 dB）横跨整个 C 波段和 X 波段，这归因于更好的阻抗匹配和更丰富的微波损耗机制。因此，C@TiC 纳米复合材料在用作具有强微波吸收能力和宽吸收带宽的吸收体方面显示出巨大的应用潜力。
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