The authentication and dating of rare ceramics is generally carried out using subjective criteria, mainly based on visual interpretation. However, the scientific study and evaluation of the materials used could contribute objectively. The analytical data relating to the major and minor elements of the coloring agents of the decoration or the base marks, and the characteristics of the raw materials (related to geology and ore processing), can be obtained on the conservation site non-invasively using a pXRF instrument and the phases formed may be identified using Raman microspectroscopy. This approach is applied to 28 objects assigned to the production of the Meissen Factory, from the collection of the Musée National de Céramique, Cité de la Céramique, Sèvres. They have polychromic or blue-and-white decorations and are supposed to have been produced in the 18th and 19th centuries. Some have a production date that has been perfectly established, others may have been produced using an earlier mold, or even have been decorated on an unknown date different from that of the firing of the biscuit. The combination of several classification criteria concerning the type of glaze, previously identified in the study of French and Chinese 17th and 18th centuries productions, i.e., the elements associated with cobalt present in the mark or the blue decoration and the relative levels of impurities of the glaze matrix, both characteristic of the raw materials and giving a strong XRF signal, leads to the identification of groups of homogeneous objects (respectively, counting seven, three, two and two objects for which at least four out of five criteria are identical); the other objects present too many differences to be considered as having been produced with the same raw materials. The first group brings together almost all the objects with a reliable pedigree made before ~1750, but includes two objects with decoration types closer to those of the 1800s. The comparison of the pXRF signals confirms the possibility of identifying the use of European ingredients for the production of painted enamels in the Qing dynasty.
稀有陶瓷的鉴定和定年一般采用主观标准进行，主要基于视觉解读。然而，对所用材料的科学研究和评价可以客观地作出贡献。利用pXRF仪器，可以在保护现场无创地获得与装饰或基础标记着色剂的主要元素和次要元素有关的分析数据，以及原材料的特征(与地质和矿石加工有关)，并可以利用拉曼显微光谱识别形成的相。这一方法适用于分配给Meissen工厂生产的28件物品，这些物品来自mus de la csamramique, cit de la csamramique, s的收集。它们有多色或蓝白装饰，应该是在18世纪和19世纪生产的。有些饼干的生产日期已经完全确定，有些饼干可能是用更早的模具生产的，甚至装饰的日期与饼干的烧制日期不同。先前在对法国和中国17世纪和18世纪产品的研究中确定的几种分类标准，即标记或蓝色装饰中存在的与钴相关的元素以及釉基质中杂质的相对水平，这两者都是原材料的特征，并发出强烈的XRF信号，导致识别同质物体组(分别计数7,3，两个和两个对象，至少五个标准中的四个是相同的);其他物体呈现出太多的差异，以至于不能被认为是用相同的原材料生产的。第一组汇集了几乎所有在1750年以前制造的具有可靠血统的物品，但包括两件装饰类型更接近于19世纪的物品。pXRF信号的比较证实了在清朝使用欧洲成分生产彩釉的可能性。
{"title":"Non-Invasive On-Site XRF and Raman Classification and Dating of Ancient Ceramics: Application to 18th and 19th Century Meissen Porcelain (Saxony) and Comparison with Chinese Porcelain","authors":"Philippe Colomban, Gulsu Simsek Franci, Mareike Gerken, Michele Gironda, Viviane Mesqui","doi":"10.3390/ceramics6040134","DOIUrl":"https://doi.org/10.3390/ceramics6040134","url":null,"abstract":"The authentication and dating of rare ceramics is generally carried out using subjective criteria, mainly based on visual interpretation. However, the scientific study and evaluation of the materials used could contribute objectively. The analytical data relating to the major and minor elements of the coloring agents of the decoration or the base marks, and the characteristics of the raw materials (related to geology and ore processing), can be obtained on the conservation site non-invasively using a pXRF instrument and the phases formed may be identified using Raman microspectroscopy. This approach is applied to 28 objects assigned to the production of the Meissen Factory, from the collection of the Musée National de Céramique, Cité de la Céramique, Sèvres. They have polychromic or blue-and-white decorations and are supposed to have been produced in the 18th and 19th centuries. Some have a production date that has been perfectly established, others may have been produced using an earlier mold, or even have been decorated on an unknown date different from that of the firing of the biscuit. The combination of several classification criteria concerning the type of glaze, previously identified in the study of French and Chinese 17th and 18th centuries productions, i.e., the elements associated with cobalt present in the mark or the blue decoration and the relative levels of impurities of the glaze matrix, both characteristic of the raw materials and giving a strong XRF signal, leads to the identification of groups of homogeneous objects (respectively, counting seven, three, two and two objects for which at least four out of five criteria are identical); the other objects present too many differences to be considered as having been produced with the same raw materials. The first group brings together almost all the objects with a reliable pedigree made before ~1750, but includes two objects with decoration types closer to those of the 1800s. The comparison of the pXRF signals confirms the possibility of identifying the use of European ingredients for the production of painted enamels in the Qing dynasty.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135037054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The freeze-drying method creates a scaffold with a composite mesoporous structure with many advantages. However, everyday materials such as β-tricalcium phosphate (β-TCP) have been used as an orthopedic implant for canine tribal bone defects for decades, for instance, for grafting material of even shapes to form an implant for our teeth. However, this material is still not entirely expected to be the best implant due to its high biodegradability. Besides that, using the piezoelectric effect on the bone can lead to more efficiency in cell growth and a faster healing time for patients. Based on this phenomenon, a scaffold composite with a piezoelectric material such as barium titanate (BaTiO3/BT) has been tested. Based on the BT/β-TCP ratio, the scaffold composite of BT and β-TCP produces a porous structure with porosity ranging from 30.25 ± 11.28 to 15.25 ± 11.28 μm. The BT/β-TCP ratio influences the samples’ pore type, which affects each sample’s mechanical properties. In our result, the scaffold of 45.0 wt% BT/45.0 wt% β-TCP/10.0 wt% collagen has achieved a significant value of 0.5 MPa for maximum stress with a sufficient pore size of 25.32 ± 8.05 μm. Finally, we performed a viability test to see the sample’s piezoelectric effect, which showed that the piezoelectric effect does increase bone healing time when tested by growing MC3T3-E1 cells on the samples.
{"title":"Preparation and Characterization of Freeze-Dried β-Tricalcium Phosphate/Barium Titanate/Collagen Composite Scaffolds for Bone Tissue Engineering in Orthopedic Applications","authors":"Dwi Fortuna Anjusa Putra, Bramantyo Bayu Aji, Henni Setia Ningsih, Ting-Wei Wu, Akihiro Nakanishi, Toshihiro Moriga, Shao-Ju Shih","doi":"10.3390/ceramics6040132","DOIUrl":"https://doi.org/10.3390/ceramics6040132","url":null,"abstract":"The freeze-drying method creates a scaffold with a composite mesoporous structure with many advantages. However, everyday materials such as β-tricalcium phosphate (β-TCP) have been used as an orthopedic implant for canine tribal bone defects for decades, for instance, for grafting material of even shapes to form an implant for our teeth. However, this material is still not entirely expected to be the best implant due to its high biodegradability. Besides that, using the piezoelectric effect on the bone can lead to more efficiency in cell growth and a faster healing time for patients. Based on this phenomenon, a scaffold composite with a piezoelectric material such as barium titanate (BaTiO3/BT) has been tested. Based on the BT/β-TCP ratio, the scaffold composite of BT and β-TCP produces a porous structure with porosity ranging from 30.25 ± 11.28 to 15.25 ± 11.28 μm. The BT/β-TCP ratio influences the samples’ pore type, which affects each sample’s mechanical properties. In our result, the scaffold of 45.0 wt% BT/45.0 wt% β-TCP/10.0 wt% collagen has achieved a significant value of 0.5 MPa for maximum stress with a sufficient pore size of 25.32 ± 8.05 μm. Finally, we performed a viability test to see the sample’s piezoelectric effect, which showed that the piezoelectric effect does increase bone healing time when tested by growing MC3T3-E1 cells on the samples.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135086878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fatien I. Al-naqshabandi, Bahar Jaafar Selivany, Abdulsalam Rasheed Al-zahawi
This study aimed to assess the biomechanical behavior of endocrown-restored mandibular molars according to “margin design” and “coverage extent” using finite element analysis (FEA). Six 3D solid models were fabricated, namely, those with complete occlusal coverage: A (butt joint), B (anatomic margin); partial coverage (two mesial cusps): C (butt joint), D (anatomic margin); and partial coverage with mesial class II cavity: E (butt joint), F (anatomic margin). All models received lithium disilicate endocrowns (2.0 mm thickness and 4.0 mm central retainer cavity depth). A 300 N vertical load was applied to the occlusal surface, while a 250 N oblique load was applied at 45° to the lingual inclined planes of the buccal cusps. The maximum von Mises stress (VMS) distribution patterns were calculated for the endocrown, tooth structure, and cement layer. The VMS on the prepared teeth and cement layer showed subtle differences between the tested models under vertical loads. The anatomic margin (partial and complete coverage) exhibited a more homogeneous stress distribution and offered a more adhesive area of the tooth structure. Under oblique loading, the anatomic margin (complete and partial), except Model D, exhibited the lowest VMS in the cement layer. An anatomically based endocrown could be a promising alternative to the butt joint design, providing better-devised endocrown restorations, which could potentially yield a more benign stress dissipation.
{"title":"Biomechanical Behavior of Lithium-Disilicate-Modified Endocrown Restorations: A Three-Dimensional Finite Element Analysis","authors":"Fatien I. Al-naqshabandi, Bahar Jaafar Selivany, Abdulsalam Rasheed Al-zahawi","doi":"10.3390/ceramics6040133","DOIUrl":"https://doi.org/10.3390/ceramics6040133","url":null,"abstract":"This study aimed to assess the biomechanical behavior of endocrown-restored mandibular molars according to “margin design” and “coverage extent” using finite element analysis (FEA). Six 3D solid models were fabricated, namely, those with complete occlusal coverage: A (butt joint), B (anatomic margin); partial coverage (two mesial cusps): C (butt joint), D (anatomic margin); and partial coverage with mesial class II cavity: E (butt joint), F (anatomic margin). All models received lithium disilicate endocrowns (2.0 mm thickness and 4.0 mm central retainer cavity depth). A 300 N vertical load was applied to the occlusal surface, while a 250 N oblique load was applied at 45° to the lingual inclined planes of the buccal cusps. The maximum von Mises stress (VMS) distribution patterns were calculated for the endocrown, tooth structure, and cement layer. The VMS on the prepared teeth and cement layer showed subtle differences between the tested models under vertical loads. The anatomic margin (partial and complete coverage) exhibited a more homogeneous stress distribution and offered a more adhesive area of the tooth structure. Under oblique loading, the anatomic margin (complete and partial), except Model D, exhibited the lowest VMS in the cement layer. An anatomically based endocrown could be a promising alternative to the butt joint design, providing better-devised endocrown restorations, which could potentially yield a more benign stress dissipation.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135086720","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marvellous Oaikhena, Abimbola E. Oluwalana-Sanusi, Puseletso P. Mokoena, Nonhlangabezo Mabuba, Themba Tshabalala, Nhamo Chaukura
Overcoming the scarcity of safe and sustainable drinking water, particularly in low-income countries, is one of the key challenges of the 21st century. In these countries, the cost of centralized water treatment facilities is prohibitive. This work examines the application of low-cost ceramic filters as point-of-use (POU) devices for the removal of methylene blue, o-toluidine blue, Staphylococcus aureus, and Staphylococcus typhi from contaminated water. The ceramic filters had typical kaolinite functional groups, making them suitable for the removal of dyes and pathogens. Surface charge measurements indicated strongly anionic filters, while thermal properties confirmed the carbonization of the biowaste additive leaving behind a porous kaolinite structure which subsequently dehydroxylated into meta kaolinite. In addition, morphological data showed heterogeneous filter surfaces. Increased biomass content improved the permeability, water adsorption, flow rate, and apparent porosity of the filter. The ceramic filter removed methylene blue (42.99–59.74%), o-toluidine (79.95–92.71%), Staphylococcus aureus (98–100%), and Staphylococcus typhi (75–100%). Overall, the study demonstrated the effectiveness of POU ceramic filters in removing organic pollutants in contaminated water while serving as disinfectants.
{"title":"Ceramic Filters for the Efficient Removal of Azo Dyes and Pathogens in Water","authors":"Marvellous Oaikhena, Abimbola E. Oluwalana-Sanusi, Puseletso P. Mokoena, Nonhlangabezo Mabuba, Themba Tshabalala, Nhamo Chaukura","doi":"10.3390/ceramics6040131","DOIUrl":"https://doi.org/10.3390/ceramics6040131","url":null,"abstract":"Overcoming the scarcity of safe and sustainable drinking water, particularly in low-income countries, is one of the key challenges of the 21st century. In these countries, the cost of centralized water treatment facilities is prohibitive. This work examines the application of low-cost ceramic filters as point-of-use (POU) devices for the removal of methylene blue, o-toluidine blue, Staphylococcus aureus, and Staphylococcus typhi from contaminated water. The ceramic filters had typical kaolinite functional groups, making them suitable for the removal of dyes and pathogens. Surface charge measurements indicated strongly anionic filters, while thermal properties confirmed the carbonization of the biowaste additive leaving behind a porous kaolinite structure which subsequently dehydroxylated into meta kaolinite. In addition, morphological data showed heterogeneous filter surfaces. Increased biomass content improved the permeability, water adsorption, flow rate, and apparent porosity of the filter. The ceramic filter removed methylene blue (42.99–59.74%), o-toluidine (79.95–92.71%), Staphylococcus aureus (98–100%), and Staphylococcus typhi (75–100%). Overall, the study demonstrated the effectiveness of POU ceramic filters in removing organic pollutants in contaminated water while serving as disinfectants.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135241606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Inspired by the process of bone formation in living organisms, many studies have been conducted to develop organic–inorganic composite materials by preparing calcium phosphate crystals within solutions or dispersions of polymers with appropriate functional groups. Bones are composite materials consisting of organic polymers (mainly type I collagen), carbonated apatite, and water, with volume fractions of 35–45%, 35–45%, and 15–25%, respectively. Carbonated apatite in bone contributes to rigidity, while organic polymers and water contribute to toughness. The inorganic crystal, carbonated apatite, is a plate-shaped crystal with dimensions of 50 nm × 25 nm × 1–4 nm, generating a significant organic–inorganic interface, due to its nanoscale size. This interface is believed to absorb externally applied forces to dissipate mechanical energy to thermal energy. Creating such nanometer-scale structures using top-down approaches is challenging, making bottom-up methods, such as the coprecipitation of polymer and inorganic crystals, more suitable. In this account, efforts to develop eco-friendly mechanical materials using biomass, such as cellulose and starch, based on the bottom-up approach to bone-like composites are described.
{"title":"Bioinspired Mechanical Materials—Development of High-Toughness Ceramics through Complexation of Calcium Phosphate and Organic Polymers","authors":"Tadashi Mizutani, Natsuki Okuda","doi":"10.3390/ceramics6040130","DOIUrl":"https://doi.org/10.3390/ceramics6040130","url":null,"abstract":"Inspired by the process of bone formation in living organisms, many studies have been conducted to develop organic–inorganic composite materials by preparing calcium phosphate crystals within solutions or dispersions of polymers with appropriate functional groups. Bones are composite materials consisting of organic polymers (mainly type I collagen), carbonated apatite, and water, with volume fractions of 35–45%, 35–45%, and 15–25%, respectively. Carbonated apatite in bone contributes to rigidity, while organic polymers and water contribute to toughness. The inorganic crystal, carbonated apatite, is a plate-shaped crystal with dimensions of 50 nm × 25 nm × 1–4 nm, generating a significant organic–inorganic interface, due to its nanoscale size. This interface is believed to absorb externally applied forces to dissipate mechanical energy to thermal energy. Creating such nanometer-scale structures using top-down approaches is challenging, making bottom-up methods, such as the coprecipitation of polymer and inorganic crystals, more suitable. In this account, efforts to develop eco-friendly mechanical materials using biomass, such as cellulose and starch, based on the bottom-up approach to bone-like composites are described.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136022907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aluminum–ceramic materials based on A12O3 and AlN are widely used in the electronics industry and, according to a number of electrophysical and technical and economic parameters, are among the most suitable for the production of electrical and radio engineering products. In this study, it is shown that the treatment of ceramics based on A12O3 with an electron beam with a power of 200–1100 W and a current of 10–50 mA leads to heating of the ceramic surface to a temperature of 1700 °C. When heated to a temperature of 1500 °C and kept at this temperature for no more than 10 s, an increase in the roughness of the ceramic surface is observed by more than an order of magnitude. At the same time, for ceramic substrates based on aluminum nitride, an increase in the temperature of electron beam treatment from 1300 to 1700 °C leads to an increase in thermal conductivity from 1.5 to 2 times. The edge angle of water wetting of the AlN surface can vary from 20 to 100 degrees depending on the processing temperature, which allows one to control the transition of the material from a hydrophilic to a hydrophobic state. At the same time, electron beam exposure to Al2O3 does not change the wettability of this material so much. Electron beam processing in the forevacuum pressure region allows controlled changes in the electrophysical properties of ceramic materials based on A12O3 and AlN.
{"title":"Electron-Beam Processing of Aluminum-Containing Ceramics in the Forevacuum Pressure Range","authors":"Aleksandr Klimov, Ilya Bakeev, Aleksey Zenin","doi":"10.3390/ceramics6040129","DOIUrl":"https://doi.org/10.3390/ceramics6040129","url":null,"abstract":"Aluminum–ceramic materials based on A12O3 and AlN are widely used in the electronics industry and, according to a number of electrophysical and technical and economic parameters, are among the most suitable for the production of electrical and radio engineering products. In this study, it is shown that the treatment of ceramics based on A12O3 with an electron beam with a power of 200–1100 W and a current of 10–50 mA leads to heating of the ceramic surface to a temperature of 1700 °C. When heated to a temperature of 1500 °C and kept at this temperature for no more than 10 s, an increase in the roughness of the ceramic surface is observed by more than an order of magnitude. At the same time, for ceramic substrates based on aluminum nitride, an increase in the temperature of electron beam treatment from 1300 to 1700 °C leads to an increase in thermal conductivity from 1.5 to 2 times. The edge angle of water wetting of the AlN surface can vary from 20 to 100 degrees depending on the processing temperature, which allows one to control the transition of the material from a hydrophilic to a hydrophobic state. At the same time, electron beam exposure to Al2O3 does not change the wettability of this material so much. Electron beam processing in the forevacuum pressure region allows controlled changes in the electrophysical properties of ceramic materials based on A12O3 and AlN.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135413525","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The possibility of synthesizing a new hybrid phosphor CSSC (mixture of 0.5 CaSrSiO4:Eu2+: 0.29 Ca6Sr4Si6O21Cl2:Eu2+: 0.21 Ca10Si6O21Cl2:Eu2+) using a one-step microwave synthesis method is demonstrated. The concentrations of europium and calcium in the synthesized phosphors were optimized at 1 and 10 mol. %, respectively, to achieve maximum brightness and color rendering index. The optimal conditions for the synthesis of phosphors in a microwave furnace were determined as 750 °C for 10 min. The resulting phosphor exhibited a wide luminescence spectrum that covered the entire visible region, resulting in a high color rendering index and a warm white luminescence when used as a light source. It is shown that the sol–gel method for preparing the charge mixture for the new phosphor allows for a 35% higher luminescence brightness compared to the solid-phase method, due to a more uniform distribution of the activator.
{"title":"One-Step Microwave Synthesis of New Hybrid Phosphor (CSSC) for White Light-Emitting Diodes","authors":"Maxim Sychov, Mariia Keskinova, Andrey Dolgin, Igor Turkin, Kazuhiko Hara, Hiroko Kominami","doi":"10.3390/ceramics6040128","DOIUrl":"https://doi.org/10.3390/ceramics6040128","url":null,"abstract":"The possibility of synthesizing a new hybrid phosphor CSSC (mixture of 0.5 CaSrSiO4:Eu2+: 0.29 Ca6Sr4Si6O21Cl2:Eu2+: 0.21 Ca10Si6O21Cl2:Eu2+) using a one-step microwave synthesis method is demonstrated. The concentrations of europium and calcium in the synthesized phosphors were optimized at 1 and 10 mol. %, respectively, to achieve maximum brightness and color rendering index. The optimal conditions for the synthesis of phosphors in a microwave furnace were determined as 750 °C for 10 min. The resulting phosphor exhibited a wide luminescence spectrum that covered the entire visible region, resulting in a high color rendering index and a warm white luminescence when used as a light source. It is shown that the sol–gel method for preparing the charge mixture for the new phosphor allows for a 35% higher luminescence brightness compared to the solid-phase method, due to a more uniform distribution of the activator.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135778879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This work examines the effects of the formation of impurity inclusions in the structure of NiAl2O4 ceramics when aluminum nitride is added to them and the occurrence of a reinforcement effect that prevents hydrogenation processes and the subsequent destruction of conductive and thermophysical characteristics. The appeal of ceramics possessing a spinel crystal structure lies in their potential use as ceramic fuel cells for both hydrogen generation and storage. Simultaneously, addressing the challenges related to ceramic degradation during hydrogenation, a critical aspect of hydrogen production, can enhance the efficiency of these ceramics while lowering electricity production costs. The selection of aluminum nitride as an additive for ceramic modification is based on its remarkable resistance to structural damage accumulation, its potential to enhance resistance to high-temperature degradation, and its ability to bolster strength properties. Moreover, an examination of the alterations in the strength characteristics of the examined samples subjected to hydrogenation reveals that the stability of two-phase ceramics is enhanced by more than three to five times compared to the initial ceramics (those without the addition of AlN). Additionally, it was noted that the most significant alterations in both structure and strength become apparent at irradiation fluences exceeding 1014 proton/cm2, where atomic displacements in the damaged ceramic layer reach over 5 dpa. During the evaluation of thermophysical properties, it was discerned that ceramics featuring an impurity phase in their composition exhibit the highest stability. These ceramics demonstrated a reduction in the thermal conductivity coefficient of less than 1% at the peak irradiation fluence.
{"title":"The Effect of the Addition of Aluminum Nitride to the Composition of NiAl2O4 Ceramics on Hydrogenation Processes and the Increase in Resistance to Swelling and Degradation","authors":"Artem L. Kozlovskiy","doi":"10.3390/ceramics6040127","DOIUrl":"https://doi.org/10.3390/ceramics6040127","url":null,"abstract":"This work examines the effects of the formation of impurity inclusions in the structure of NiAl2O4 ceramics when aluminum nitride is added to them and the occurrence of a reinforcement effect that prevents hydrogenation processes and the subsequent destruction of conductive and thermophysical characteristics. The appeal of ceramics possessing a spinel crystal structure lies in their potential use as ceramic fuel cells for both hydrogen generation and storage. Simultaneously, addressing the challenges related to ceramic degradation during hydrogenation, a critical aspect of hydrogen production, can enhance the efficiency of these ceramics while lowering electricity production costs. The selection of aluminum nitride as an additive for ceramic modification is based on its remarkable resistance to structural damage accumulation, its potential to enhance resistance to high-temperature degradation, and its ability to bolster strength properties. Moreover, an examination of the alterations in the strength characteristics of the examined samples subjected to hydrogenation reveals that the stability of two-phase ceramics is enhanced by more than three to five times compared to the initial ceramics (those without the addition of AlN). Additionally, it was noted that the most significant alterations in both structure and strength become apparent at irradiation fluences exceeding 1014 proton/cm2, where atomic displacements in the damaged ceramic layer reach over 5 dpa. During the evaluation of thermophysical properties, it was discerned that ceramics featuring an impurity phase in their composition exhibit the highest stability. These ceramics demonstrated a reduction in the thermal conductivity coefficient of less than 1% at the peak irradiation fluence.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135729671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mustafa K. Alazzawi, Chawon Hwang, Victoria R. Tsarkova, Richard A. Haber
Controlling the feature resolution and dimension of printed products using stereolithography requires a comprehensive understanding of compositional and printing variables. Balancing these variables adds more complexity to manufacturing near net shape products. In this study, the compositional variables examined include particle size and solid content using two resins, and printing variables include layer thickness and energy dose. Choosing the energy dose for curing depends on compositional variables and consequently affects the degree of scattering. The results shows that light scattering determines the changes in the feature resolution and lateral dimensions. The layer thickness only affects the feature resolution and not the lateral dimensions. The vertical dimension does not significantly change with the chosen variables. In this study, fine-tuning the variables is shown to produce parts with high precision and resolution. Both compositional and printing variables play a key role in achieving near net shape products.
{"title":"The Feature Resolution and Dimensional Control in Freeform Solidification of Alumina Systems by Stereolithography","authors":"Mustafa K. Alazzawi, Chawon Hwang, Victoria R. Tsarkova, Richard A. Haber","doi":"10.3390/ceramics6040125","DOIUrl":"https://doi.org/10.3390/ceramics6040125","url":null,"abstract":"Controlling the feature resolution and dimension of printed products using stereolithography requires a comprehensive understanding of compositional and printing variables. Balancing these variables adds more complexity to manufacturing near net shape products. In this study, the compositional variables examined include particle size and solid content using two resins, and printing variables include layer thickness and energy dose. Choosing the energy dose for curing depends on compositional variables and consequently affects the degree of scattering. The results shows that light scattering determines the changes in the feature resolution and lateral dimensions. The layer thickness only affects the feature resolution and not the lateral dimensions. The vertical dimension does not significantly change with the chosen variables. In this study, fine-tuning the variables is shown to produce parts with high precision and resolution. Both compositional and printing variables play a key role in achieving near net shape products.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136033407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In assessing the bending attributes for geopolymer composites augmented with uni-directional fibers, methodologies aligned with the established American and European standards yield quantifiable values for flexural strength, denoted as σm*, and its corresponding elasticity modulus, E*. Notably, these values exhibit a pronounced dependency on the size of the testing parameters. Specifically, within a judicious range of support span L relative to specimen height H, spanning a ratio of 10 to 40, these metrics can vary by a factor between 2 and 4. By conducting evaluations across an extensive array of H/L ratios and adhering to the protocols set for comparable composites with a plastic matrix, it becomes feasible to determine the definitive flexural elastic modulus E and shear modulus G, both of which can be viewed as size-neutral material traits. A parallel methodology can be employed to deduce size-agnostic values for flexural strength, σm. The established linear relationship between the inverse practical value E* (1/E*) and the squared ratio (H/L)2 is acknowledged. However, a congruent 1/σm* relationship has been recently corroborated experimentally, aligning primarily with Tarnopolsky’s theoretical propositions. The parameter T, defined as the inverse gradient of 1/σm* about (H/L)2, is integral to these findings. Furthermore, the significance of the loading displacement rate is underscored, necessitating a tailored consideration for different scenarios.
{"title":"Size-Independent Flexure Test Technique for the Mechanical Properties of Geocomposites Reinforced by Unidirectional Fibers","authors":"Hung Tran Doan, Dora Kroisova, Oleg Bortnovsky","doi":"10.3390/ceramics6040126","DOIUrl":"https://doi.org/10.3390/ceramics6040126","url":null,"abstract":"In assessing the bending attributes for geopolymer composites augmented with uni-directional fibers, methodologies aligned with the established American and European standards yield quantifiable values for flexural strength, denoted as σm*, and its corresponding elasticity modulus, E*. Notably, these values exhibit a pronounced dependency on the size of the testing parameters. Specifically, within a judicious range of support span L relative to specimen height H, spanning a ratio of 10 to 40, these metrics can vary by a factor between 2 and 4. By conducting evaluations across an extensive array of H/L ratios and adhering to the protocols set for comparable composites with a plastic matrix, it becomes feasible to determine the definitive flexural elastic modulus E and shear modulus G, both of which can be viewed as size-neutral material traits. A parallel methodology can be employed to deduce size-agnostic values for flexural strength, σm. The established linear relationship between the inverse practical value E* (1/E*) and the squared ratio (H/L)2 is acknowledged. However, a congruent 1/σm* relationship has been recently corroborated experimentally, aligning primarily with Tarnopolsky’s theoretical propositions. The parameter T, defined as the inverse gradient of 1/σm* about (H/L)2, is integral to these findings. Furthermore, the significance of the loading displacement rate is underscored, necessitating a tailored consideration for different scenarios.","PeriodicalId":33263,"journal":{"name":"Ceramics-Switzerland","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136038271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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