Pub Date : 2023-01-02DOI: 10.1080/17436753.2023.2184593
Pongpen Kaewdee, A. Limpichaipanit, Chamnan Randorn, Sujitra Tandorn
ABSTRACT Lanthanum-doped strontium titanate powder, La0.05Sr0.95TiO3+δ, was fabricated by peroxide-based route and calcination of freshly prepared precipitate and precipitate after ageing was carried out. The starting titanium precursor was titanium nitride, which underwent the reaction to form titanium peroxohydroxide and then compound containing strontium and lanthanum. A perovskite structure of strontium titanate with 5 mol-% doped lanthanum was obtained after calcination of the freshly-prepared precipitate at 500°C. However, the ageing powder revealed the presence of the second phase of strontium carbonate after calcination at the same condition. Thermogravimetric results showed that the decomposition of ammonia promoted a reaction to form the pure phase of ceramic oxide only in the freshly calcined sample.
{"title":"Facile and composition controllable synthesis of lanthanum-doped strontium titanate via peroxide route","authors":"Pongpen Kaewdee, A. Limpichaipanit, Chamnan Randorn, Sujitra Tandorn","doi":"10.1080/17436753.2023.2184593","DOIUrl":"https://doi.org/10.1080/17436753.2023.2184593","url":null,"abstract":"ABSTRACT Lanthanum-doped strontium titanate powder, La0.05Sr0.95TiO3+δ, was fabricated by peroxide-based route and calcination of freshly prepared precipitate and precipitate after ageing was carried out. The starting titanium precursor was titanium nitride, which underwent the reaction to form titanium peroxohydroxide and then compound containing strontium and lanthanum. A perovskite structure of strontium titanate with 5 mol-% doped lanthanum was obtained after calcination of the freshly-prepared precipitate at 500°C. However, the ageing powder revealed the presence of the second phase of strontium carbonate after calcination at the same condition. Thermogravimetric results showed that the decomposition of ammonia promoted a reaction to form the pure phase of ceramic oxide only in the freshly calcined sample.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"1 1","pages":"17 - 21"},"PeriodicalIF":2.2,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88632365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-02DOI: 10.1080/17436753.2023.2193783
A. Paksoy, P. Xiao
ABSTRACT SiC-reinforced SiC ceramic matrix composites (SiC/SiC CMCs) are considered promising candidates to replace their super alloy counterparts due to higher temperature capabilities and lower densities. However, high-temperature and high-pressure water vapour sourced from the hydrocarbons’ combustion reactions inhibit the potential of SiC/SiC CMCs by leading to rapid surface recession. In order to address this challenge, environmental barrier coatings (EBCs) have been developed. The emphasis of this review is on the materials and processing techniques for the development of EBC systems. In the first part of the review, the characteristics of the SiC/SiC CMCs and the most common EBC materials are summarised. Then, the interrelationship between processing methods, microstructures and the resulting properties is reviewed. Finally, an overview of the future directions is outlined to assist developments in advanced and novel EBCs for next generation gas turbines.
{"title":"Review of processing and design methodologies of environmental barrier coatings for next generation gas turbine applications","authors":"A. Paksoy, P. Xiao","doi":"10.1080/17436753.2023.2193783","DOIUrl":"https://doi.org/10.1080/17436753.2023.2193783","url":null,"abstract":"ABSTRACT SiC-reinforced SiC ceramic matrix composites (SiC/SiC CMCs) are considered promising candidates to replace their super alloy counterparts due to higher temperature capabilities and lower densities. However, high-temperature and high-pressure water vapour sourced from the hydrocarbons’ combustion reactions inhibit the potential of SiC/SiC CMCs by leading to rapid surface recession. In order to address this challenge, environmental barrier coatings (EBCs) have been developed. The emphasis of this review is on the materials and processing techniques for the development of EBC systems. In the first part of the review, the characteristics of the SiC/SiC CMCs and the most common EBC materials are summarised. Then, the interrelationship between processing methods, microstructures and the resulting properties is reviewed. Finally, an overview of the future directions is outlined to assist developments in advanced and novel EBCs for next generation gas turbines.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"51 1","pages":"36 - 56"},"PeriodicalIF":2.2,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75546994","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-02DOI: 10.1080/17436753.2023.2182993
Takashi Kojima, Tsukasa Baba, Kohei Inamoto, Rena Isowaki, Chieko Yukita, Kazuya Ujiie, Akiko Takeda, F. Shiba, N. Uekawa
ABSTRACT Uniform-sized amorphous hydrous titania particles (HTPs) with nonporous or porous surface were prepared and subjected to hot-water or hydrothermal treatment to induce crystallisation of the titania phase for preparing porous titania particles with high specific surface area (SSA) and outer diameter in a micron order. Porous HTPs were crystallised under milder treatment conditions than those required to crystallise nonporous spherical HTPs. This difference was attributed to the difference in the polycondensation states of hydrous titania. The SSA of the porous titania particles crystallised by hot-water treatment at 80°C for 24 h was 216 m2 g−1, despite their micron-order particle size. This simple method can synthesise highly functional titania particles at low temperatures and is a general-purpose method for preparing porous particles for use as adsorbents, catalysts and catalyst supports.
{"title":"Preparation of porous titania particles by partial dissolution and hot-water or hydrothermal treatment of hydrous titania","authors":"Takashi Kojima, Tsukasa Baba, Kohei Inamoto, Rena Isowaki, Chieko Yukita, Kazuya Ujiie, Akiko Takeda, F. Shiba, N. Uekawa","doi":"10.1080/17436753.2023.2182993","DOIUrl":"https://doi.org/10.1080/17436753.2023.2182993","url":null,"abstract":"ABSTRACT Uniform-sized amorphous hydrous titania particles (HTPs) with nonporous or porous surface were prepared and subjected to hot-water or hydrothermal treatment to induce crystallisation of the titania phase for preparing porous titania particles with high specific surface area (SSA) and outer diameter in a micron order. Porous HTPs were crystallised under milder treatment conditions than those required to crystallise nonporous spherical HTPs. This difference was attributed to the difference in the polycondensation states of hydrous titania. The SSA of the porous titania particles crystallised by hot-water treatment at 80°C for 24 h was 216 m2 g−1, despite their micron-order particle size. This simple method can synthesise highly functional titania particles at low temperatures and is a general-purpose method for preparing porous particles for use as adsorbents, catalysts and catalyst supports.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"108 1","pages":"10 - 16"},"PeriodicalIF":2.2,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81512754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-17DOI: 10.1080/17436753.2022.2156066
Shafique Ahmed, L. Zou, Haixue Yan
ABSTRACT Yttria-stabilised zirconia (Y-TZP) ceramics are widely used for dental and prosthesis applications; however, they are susceptible to low-temperature degradation (LTD). Despite several explanations of the LTD mechanism, it is not fully understood yet. Commercial TZ-3Y-E grade powder was used to further study the LTD before sintering it. Hydrothermal ageing treatment was applied to samples at 134°C for 5 h. STA analysis confirmed that the powder is binderfree. SEM and XRD analyses show homogeneous particle size and tetragonal as a major phase and monoclinic as a minor phase, respectively. BET method analysis shows a slight change in the pore size, pore volume and surface area of the powder samples, before and after heating at 400°C. Particle size distribution (SD) calculated from SEM images shows ∼ 40–50 nm particle size range of the powders. The results show that LTD was not observed in the powder after hydrothermal ageing treatment.
{"title":"Stability of 3Y-TZP nano zirconia powder after hydrothermal ageing treatment","authors":"Shafique Ahmed, L. Zou, Haixue Yan","doi":"10.1080/17436753.2022.2156066","DOIUrl":"https://doi.org/10.1080/17436753.2022.2156066","url":null,"abstract":"ABSTRACT Yttria-stabilised zirconia (Y-TZP) ceramics are widely used for dental and prosthesis applications; however, they are susceptible to low-temperature degradation (LTD). Despite several explanations of the LTD mechanism, it is not fully understood yet. Commercial TZ-3Y-E grade powder was used to further study the LTD before sintering it. Hydrothermal ageing treatment was applied to samples at 134°C for 5 h. STA analysis confirmed that the powder is binderfree. SEM and XRD analyses show homogeneous particle size and tetragonal as a major phase and monoclinic as a minor phase, respectively. BET method analysis shows a slight change in the pore size, pore volume and surface area of the powder samples, before and after heating at 400°C. Particle size distribution (SD) calculated from SEM images shows ∼ 40–50 nm particle size range of the powders. The results show that LTD was not observed in the powder after hydrothermal ageing treatment.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"386 1","pages":"159 - 165"},"PeriodicalIF":2.2,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80024995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-17DOI: 10.1080/17436753.2022.2152595
Yu Wang, Yuehua Wu, Guo-hua Zhang, K. Chou
ABSTRACT Zirconium diboride (ZrB2) is a typical ultra-high temperature ceramic material (UHTC). In this work, the preparation of ZrB2 by reducing zirconia (ZrO2) with calcium hexaboride (CaB6) was studied in detail. With the assistance of molten salt, the reduction rate was dramatically enhanced. Additionally, the results showed that ZrB2 products with different particle shapes were prepared by changing the type of molten salt (NaCl, KCl, MgCl2, and CaCl2). However, the particle size of products could not be properly refined when nano-ZrO2 was used as the raw material. During the process of reducing ZrO2 by CaB6, B2O3 could be formed, which would cause the loss of B source. To decrease the consumption of CaB6, Ca-assisted reduction was performed, and monophase ZrB2 was obtained. The varied morphologies of ZrB2 particles obtained by Ca-assisted reduction were the result of complex reaction mechanisms.
{"title":"Preparation of zirconium diboride by reduction of zirconia with calcium hexaboride","authors":"Yu Wang, Yuehua Wu, Guo-hua Zhang, K. Chou","doi":"10.1080/17436753.2022.2152595","DOIUrl":"https://doi.org/10.1080/17436753.2022.2152595","url":null,"abstract":"ABSTRACT Zirconium diboride (ZrB2) is a typical ultra-high temperature ceramic material (UHTC). In this work, the preparation of ZrB2 by reducing zirconia (ZrO2) with calcium hexaboride (CaB6) was studied in detail. With the assistance of molten salt, the reduction rate was dramatically enhanced. Additionally, the results showed that ZrB2 products with different particle shapes were prepared by changing the type of molten salt (NaCl, KCl, MgCl2, and CaCl2). However, the particle size of products could not be properly refined when nano-ZrO2 was used as the raw material. During the process of reducing ZrO2 by CaB6, B2O3 could be formed, which would cause the loss of B source. To decrease the consumption of CaB6, Ca-assisted reduction was performed, and monophase ZrB2 was obtained. The varied morphologies of ZrB2 particles obtained by Ca-assisted reduction were the result of complex reaction mechanisms.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"1 1","pages":"177 - 184"},"PeriodicalIF":2.2,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80415105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-17DOI: 10.1080/17436753.2023.2167680
S. Saran, Y. Eker, Ş. Ateş, G. Çelik, Hadi Baveghar, O. M. Özkendir, Ü. Atav, W. Klysubun
ABSTRACT Garnet-type solid-state electrolytes are promising candidates for solid-state lithium batteries, nevertheless their ionic conductivity is still not enough for commercial applications. On the other hand, doping still is the common way to improve the ionic conductivities of these solid electrolytes. In this study, mono and dual-doped garnet-type solid electrolytes were synthesised by substituting indium (In), gallium (Ga), indium-titanium (In-Ti) and gallium-titanium (Ga-Ti) to the Li7La3Zr2O12 structure by a solid-state reaction method. The contribution of substitutions to the formation of crystal phases was investigated by X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS). On the other hand, morphological analyses were done by scanning electron microscope (SEM) and the ionic conductivities of the solid electrolytes were determined by electrochemical impedance spectroscopy (EIS). The study showed that while Li7-3xInxLa3Zr2O12 (for x = 0.05, 0.10, 0.15, 0.20) and Li7-3xGaxLa3Zr2O12 (for x = 0.05) samples were formed in tetragonal phase with a space group of I41/acd:2, dual substituted Li7-3xInxLa3Zr1.8Ti0.2O12 and Li7-3xGaxLa3Zr1.8Ti0.2O12 solid electrolytes for all x values were formed in cubic phase with a space group of I-43d. The highest conductivity is reached for Li6.85Ga0.05La3Zr1.8Ti0.2O12. The radial distribution function studies showed that when more In and Ga atoms take place in the sites of Li atoms, more O atoms take place in the vicinity of both substituted In and Ga atoms within the Li7La3Zr1.8Ti0.2O12 (LLZTO) crystal framework which can eventuate in a change in the conduction mechanism.
{"title":"The effect of Ti to the crystal structure of Li7-3xMxLa3Zr1.8Ti0.2O12 (M= Ga, In) garnet-type solid electrolytes as a second dopant","authors":"S. Saran, Y. Eker, Ş. Ateş, G. Çelik, Hadi Baveghar, O. M. Özkendir, Ü. Atav, W. Klysubun","doi":"10.1080/17436753.2023.2167680","DOIUrl":"https://doi.org/10.1080/17436753.2023.2167680","url":null,"abstract":"ABSTRACT Garnet-type solid-state electrolytes are promising candidates for solid-state lithium batteries, nevertheless their ionic conductivity is still not enough for commercial applications. On the other hand, doping still is the common way to improve the ionic conductivities of these solid electrolytes. In this study, mono and dual-doped garnet-type solid electrolytes were synthesised by substituting indium (In), gallium (Ga), indium-titanium (In-Ti) and gallium-titanium (Ga-Ti) to the Li7La3Zr2O12 structure by a solid-state reaction method. The contribution of substitutions to the formation of crystal phases was investigated by X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS). On the other hand, morphological analyses were done by scanning electron microscope (SEM) and the ionic conductivities of the solid electrolytes were determined by electrochemical impedance spectroscopy (EIS). The study showed that while Li7-3xInxLa3Zr2O12 (for x = 0.05, 0.10, 0.15, 0.20) and Li7-3xGaxLa3Zr2O12 (for x = 0.05) samples were formed in tetragonal phase with a space group of I41/acd:2, dual substituted Li7-3xInxLa3Zr1.8Ti0.2O12 and Li7-3xGaxLa3Zr1.8Ti0.2O12 solid electrolytes for all x values were formed in cubic phase with a space group of I-43d. The highest conductivity is reached for Li6.85Ga0.05La3Zr1.8Ti0.2O12. The radial distribution function studies showed that when more In and Ga atoms take place in the sites of Li atoms, more O atoms take place in the vicinity of both substituted In and Ga atoms within the Li7La3Zr1.8Ti0.2O12 (LLZTO) crystal framework which can eventuate in a change in the conduction mechanism.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"12 1","pages":"238 - 246"},"PeriodicalIF":2.2,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87995390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-17DOI: 10.1080/17436753.2023.2164997
Xinduo Huang, Tingting Zhao, Tongcai Wang, Shan Li, Gong Wang
ABSTRACT The binder jetting (BJ) process shows significant superiority in manufacturing ceramic parts with a complex structure. The performance of the green part is highly reliant on the features of raw materials. A kind of grading zirconia powder M0 was designed, its intrinsic characteristics including microstructure, size and size distribution, bulk density, porosity, hall velocity and spread performance were systematically evaluated. The design principles of M0 were illustrated in detail. Meanwhile, a kind of organic epoxy binder was prepared and its properties including density, viscosity and surface tension were estimated. The jet ability of binder was evaluated quantitatively. The compatibility and bonding strength between binder and powder were assessed through contact angle, infiltration time and microstructure of M0. As a result, M0 and epoxy binder can be successfully applied in the printer, the zirconia structure with good dimensional accuracy (shrinkage rate ≤ ±2%) and flexible strength (1.74 ± 0.28 MPa) were achieved.
{"title":"Binder jetting printing of zirconia structures via grading powder and epoxy binder","authors":"Xinduo Huang, Tingting Zhao, Tongcai Wang, Shan Li, Gong Wang","doi":"10.1080/17436753.2023.2164997","DOIUrl":"https://doi.org/10.1080/17436753.2023.2164997","url":null,"abstract":"ABSTRACT The binder jetting (BJ) process shows significant superiority in manufacturing ceramic parts with a complex structure. The performance of the green part is highly reliant on the features of raw materials. A kind of grading zirconia powder M0 was designed, its intrinsic characteristics including microstructure, size and size distribution, bulk density, porosity, hall velocity and spread performance were systematically evaluated. The design principles of M0 were illustrated in detail. Meanwhile, a kind of organic epoxy binder was prepared and its properties including density, viscosity and surface tension were estimated. The jet ability of binder was evaluated quantitatively. The compatibility and bonding strength between binder and powder were assessed through contact angle, infiltration time and microstructure of M0. As a result, M0 and epoxy binder can be successfully applied in the printer, the zirconia structure with good dimensional accuracy (shrinkage rate ≤ ±2%) and flexible strength (1.74 ± 0.28 MPa) were achieved.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"23 1","pages":"231 - 237"},"PeriodicalIF":2.2,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83118806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT Carbon fibre has excellent mechanical properties at high temperatures but weak oxidation resistance. The paper prepared the anti-oxidative silica coating on the surface of needled carbon fibre felt by the sol–gel method and discussed the effects of sol content and sintering temperature on the coatings’ performance. The phase composition, density, thermal conductivity and thermal stability of derived composites were characterised, and the structure and morphology of SiO2 coatings were also analysed by scanning electron microscopy. The results indicated that a uniform and complete coating could be formed on the fibre surface when the sol content exceeds 20%. Ceramic particles sintered below 1200°C were amorphous silica, while those sintered at 1350°C were cristobalite. Compared with other processes, 20% silica sol content or sintering at 1350°C could provide better antioxidant protection. The new coating process is significant for retarding fibre oxidation in a high-temperature environment.
{"title":"Effects of sol contents and sintering temperatures on SiO2 coated needled carbon fibre felt composites","authors":"Shuang Wang, Qunjiao Chen, Haiming Huang, Weijie Li, Buyue Zhao","doi":"10.1080/17436753.2022.2155370","DOIUrl":"https://doi.org/10.1080/17436753.2022.2155370","url":null,"abstract":"ABSTRACT Carbon fibre has excellent mechanical properties at high temperatures but weak oxidation resistance. The paper prepared the anti-oxidative silica coating on the surface of needled carbon fibre felt by the sol–gel method and discussed the effects of sol content and sintering temperature on the coatings’ performance. The phase composition, density, thermal conductivity and thermal stability of derived composites were characterised, and the structure and morphology of SiO2 coatings were also analysed by scanning electron microscopy. The results indicated that a uniform and complete coating could be formed on the fibre surface when the sol content exceeds 20%. Ceramic particles sintered below 1200°C were amorphous silica, while those sintered at 1350°C were cristobalite. Compared with other processes, 20% silica sol content or sintering at 1350°C could provide better antioxidant protection. The new coating process is significant for retarding fibre oxidation in a high-temperature environment.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"1 1","pages":"193 - 201"},"PeriodicalIF":2.2,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74073756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT Anti-oxidation coatings of MoSi2-SiC-Si-ZrB2 were prepared on the graphite surface by laser cladding. The XRD, scratching bonding force, SEM and isothermal oxidation tests were used to investigate the microstructure and properties of the coatings. The coating with 40 wt% ZrB2 added (MoSi2:SiC:Si:ZrB2 = 16:4:5:16.6) has the lowest degree of oxidation, the best oxidation resistance and the highest bonding strength between coating and matrix. The scratching bonding force still maintained at about 9.9 N after laser ablation, and there were no obvious destructive defects but some pores and cracks on the coating. After a Si-enriched amorphous layer was formed, the relative oxygen permeability was significantly decreased and the oxidation of the coating was passivated, which prevented the matrix from further oxidation.
{"title":"Preparation and oxidation behaviour of MoSi2-SiC-Si-ZrB2 composite coatings on carbon surface via laser cladding","authors":"Xuemei Liu, Weixin Chen, X. Tao, Heliang Fan, Zhangsheng Liu, Y. Ling, Litong Guo","doi":"10.1080/17436753.2022.2155372","DOIUrl":"https://doi.org/10.1080/17436753.2022.2155372","url":null,"abstract":"ABSTRACT Anti-oxidation coatings of MoSi2-SiC-Si-ZrB2 were prepared on the graphite surface by laser cladding. The XRD, scratching bonding force, SEM and isothermal oxidation tests were used to investigate the microstructure and properties of the coatings. The coating with 40 wt% ZrB2 added (MoSi2:SiC:Si:ZrB2 = 16:4:5:16.6) has the lowest degree of oxidation, the best oxidation resistance and the highest bonding strength between coating and matrix. The scratching bonding force still maintained at about 9.9 N after laser ablation, and there were no obvious destructive defects but some pores and cracks on the coating. After a Si-enriched amorphous layer was formed, the relative oxygen permeability was significantly decreased and the oxidation of the coating was passivated, which prevented the matrix from further oxidation.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"1 1","pages":"202 - 210"},"PeriodicalIF":2.2,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88023930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-11-17DOI: 10.1080/17436753.2023.2170618
Cristian Casut, R. Bucur, N. Miclău, I. Malaescu, M. Miclau
ABSTRACT From a new perspective, polymorphism is now often considered as a functional property that extends the applications of many materials. BiFeO3 is still an interesting material from both fundamental and applied points of view. A unique characteristic of BiFeO3 film, the polymorphism was stabilised only using the epitaxial strain caused by the substrate of the film. Here we report the hydrothermal synthesis of biphasic BiFeO3 ceramics using low NaOH concentration and temperature. The ability of BiFeO3 ceramics to morph into tetragonal and rhombohedral allotropic phases was demonstrated, confirming the theoretical prediction that the polymorphism can be stabilised even in powder form. Based on our experimental study NaOH(aq) is proposed as responsible for the strain on the structure of the rhombohedral phase. In addition, the in-depth characterisation of this biphasic ceramic opens up new opportunities for the technological applications of BiFeO3 material.
{"title":"Biphasic BiFeO3 ceramics based on rhombohedral and tetragonal polymorphs","authors":"Cristian Casut, R. Bucur, N. Miclău, I. Malaescu, M. Miclau","doi":"10.1080/17436753.2023.2170618","DOIUrl":"https://doi.org/10.1080/17436753.2023.2170618","url":null,"abstract":"ABSTRACT From a new perspective, polymorphism is now often considered as a functional property that extends the applications of many materials. BiFeO3 is still an interesting material from both fundamental and applied points of view. A unique characteristic of BiFeO3 film, the polymorphism was stabilised only using the epitaxial strain caused by the substrate of the film. Here we report the hydrothermal synthesis of biphasic BiFeO3 ceramics using low NaOH concentration and temperature. The ability of BiFeO3 ceramics to morph into tetragonal and rhombohedral allotropic phases was demonstrated, confirming the theoretical prediction that the polymorphism can be stabilised even in powder form. Based on our experimental study NaOH(aq) is proposed as responsible for the strain on the structure of the rhombohedral phase. In addition, the in-depth characterisation of this biphasic ceramic opens up new opportunities for the technological applications of BiFeO3 material.","PeriodicalId":7224,"journal":{"name":"Advances in Applied Ceramics","volume":"24 1","pages":"247 - 254"},"PeriodicalIF":2.2,"publicationDate":"2022-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74314494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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