Pub Date : 2024-11-07DOI: 10.1016/j.jeurceramsoc.2024.117061
Min Xu , Yue Xia , Haonan Li , Guanfeng Wu , Chengjie Zhao , Qian Liao , Hai Wang , Chunguang Li , Longcheng Liu , Hiroshi Watabe , Yuhong Li
A series of compositionally complex A2Zr2O7 nanocrystalline ceramics were successfully prepared using sol-gel and co-precipitation methods. The resultant ceramics possess a cubic defect fluorite structure, with the sol-gel method yielding an average grain size of approximately 50–70 nm, while the co-precipitation method result in an average grain size of about 40–60 nm. Leaching tests revealed that the smaller grain sizes are correlated with higher leaching rates. Furthermore, for ceramics with similar grain sizes, those with higher entropy values exhibited higher leaching rates. The increase in grain boundaries was found to reduce the leaching performance of the rare earth zirconate ceramics, and this effect became more pronounced with increasing entropy. This work provides insights into the selection of entropy values and grain sizes for the high-level radioactive waste matrices, which can be considered as a potential substrate for the simultaneous immobilization of multiple radionuclides.
{"title":"The effect of entropy on the structure and aqueous durability of nanocrystalline rare-earth zirconate ceramics","authors":"Min Xu , Yue Xia , Haonan Li , Guanfeng Wu , Chengjie Zhao , Qian Liao , Hai Wang , Chunguang Li , Longcheng Liu , Hiroshi Watabe , Yuhong Li","doi":"10.1016/j.jeurceramsoc.2024.117061","DOIUrl":"10.1016/j.jeurceramsoc.2024.117061","url":null,"abstract":"<div><div>A series of compositionally complex A<sub>2</sub>Zr<sub>2</sub>O<sub>7</sub> nanocrystalline ceramics were successfully prepared using sol-gel and co-precipitation methods. The resultant ceramics possess a cubic defect fluorite structure, with the sol-gel method yielding an average grain size of approximately 50–70 nm, while the co-precipitation method result in an average grain size of about 40–60 nm. Leaching tests revealed that the smaller grain sizes are correlated with higher leaching rates. Furthermore, for ceramics with similar grain sizes, those with higher entropy values exhibited higher leaching rates. The increase in grain boundaries was found to reduce the leaching performance of the rare earth zirconate ceramics, and this effect became more pronounced with increasing entropy. This work provides insights into the selection of entropy values and grain sizes for the high-level radioactive waste matrices, which can be considered as a potential substrate for the simultaneous immobilization of multiple radionuclides.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 3","pages":"Article 117061"},"PeriodicalIF":5.8,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-11-07DOI: 10.1016/j.jeurceramsoc.2024.117063
Seyed Ali Razavi , Gemma Fargas , Isabel Serrano , Miguel Ángel Laguna-Bercero , Luis Llanes , Jordi Llorca , Miguel Morales
Direct Ink Writing (DIW) is a promising technique for fabricating ceramic catalysts with complex geometries and enhanced catalytic performances, but these still require overcoming some challenges to maximize their catalytic and mechanical functionality. In this work, DIW yttria-doped zirconia (YDZ) catalysts were coated with a Co/YDZ catalyst layer. Two configurations based on a dense monolith and a porous one sintered at 1450ºC and 1300ºC were fabricated through DIW, using optimal rheological hydrogel-inks, to investigate the effect of porosity on the mechanical and catalytic performance in the ethanol steam reforming reaction. The monolith sintered at 1450°C achieved the best mechanical and catalytic performance, as it presented the highest Co concentration (2.3 at%) at the catalyst layer. In addition, this monolith exhibited excellent mechanical properties at the interface between contiguous filaments in the multilayer structure. Therefore, this simple approach is a promising method to produce enhanced catalytically and mechanically robust monoliths.
{"title":"Cobalt-Zirconia coated monoliths fabricated by Direct Ink Writing for catalytic applications","authors":"Seyed Ali Razavi , Gemma Fargas , Isabel Serrano , Miguel Ángel Laguna-Bercero , Luis Llanes , Jordi Llorca , Miguel Morales","doi":"10.1016/j.jeurceramsoc.2024.117063","DOIUrl":"10.1016/j.jeurceramsoc.2024.117063","url":null,"abstract":"<div><div>Direct Ink Writing (DIW) is a promising technique for fabricating ceramic catalysts with complex geometries and enhanced catalytic performances, but these still require overcoming some challenges to maximize their catalytic and mechanical functionality. In this work, DIW yttria-doped zirconia (YDZ) catalysts were coated with a Co/YDZ catalyst layer. Two configurations based on a dense monolith and a porous one sintered at 1450ºC and 1300ºC were fabricated through DIW, using optimal rheological hydrogel-inks, to investigate the effect of porosity on the mechanical and catalytic performance in the ethanol steam reforming reaction. The monolith sintered at 1450°C achieved the best mechanical and catalytic performance, as it presented the highest Co concentration (2.3 at%) at the catalyst layer. In addition, this monolith exhibited excellent mechanical properties at the interface between contiguous filaments in the multilayer structure. Therefore, this simple approach is a promising method to produce enhanced catalytically and mechanically robust monoliths.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 3","pages":"Article 117063"},"PeriodicalIF":5.8,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-11-06DOI: 10.1016/j.jeurceramsoc.2024.117058
Panpan Zhang , Yi Tang , Junmeng Jing , Ziwei Zheng , Jieshan Chang , Haoran Wang , Qi Wang , Zheng Yang , Zhibin Yang
Calcium-based perovskite La0.6Ca0.4Fe0.8Co0.2O3-δ (LCFC) with stable structure is the promising air electrode used in reversible solid oxide cells, and its application in cell stack must consider its Cr poisoning resistance ability. Herein, the Cr poisoning effect of it is studied in this work. The results indicate the strong reaction between LCFC and the Cr contaminations, forming undesirable CaCrO4 impurities, which significantly reduce the activity of ORR/OER. Both the decayed performance and reversible stability are also observed in SOFC and SOEC modes under the Cr contaminations, and the main reason comes from the reduced activity of the oxygen surface exchange processes and the blocked gas diffusion process by the impurities. A worse degenerated performance in SOFC mode than that in SOEC mode is also found in this work. Beyond that, the mechanism of the reaction between chromium contaminants and the Ca-segregation of the electrodes is discussed by the nucleation theory.
{"title":"Revealing the degradation mechanism of calcium-based air electrodes in reversible solid oxide cells under chromium contaminants","authors":"Panpan Zhang , Yi Tang , Junmeng Jing , Ziwei Zheng , Jieshan Chang , Haoran Wang , Qi Wang , Zheng Yang , Zhibin Yang","doi":"10.1016/j.jeurceramsoc.2024.117058","DOIUrl":"10.1016/j.jeurceramsoc.2024.117058","url":null,"abstract":"<div><div>Calcium-based perovskite La<sub>0.6</sub>Ca<sub>0.4</sub>Fe<sub>0.8</sub>Co<sub>0.2</sub>O<sub>3-δ</sub> (LCFC) with stable structure is the promising air electrode used in reversible solid oxide cells, and its application in cell stack must consider its Cr poisoning resistance ability. Herein, the Cr poisoning effect of it is studied in this work. The results indicate the strong reaction between LCFC and the Cr contaminations, forming undesirable CaCrO<sub>4</sub> impurities, which significantly reduce the activity of ORR/OER. Both the decayed performance and reversible stability are also observed in SOFC and SOEC modes under the Cr contaminations, and the main reason comes from the reduced activity of the oxygen surface exchange processes and the blocked gas diffusion process by the impurities. A worse degenerated performance in SOFC mode than that in SOEC mode is also found in this work. Beyond that, the mechanism of the reaction between chromium contaminants and the Ca-segregation of the electrodes is discussed by the nucleation theory.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 4","pages":"Article 117058"},"PeriodicalIF":5.8,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657701","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-11-06DOI: 10.1016/j.jeurceramsoc.2024.117055
Rui Zhao , Chao Ma , Hongtian He , Ying Li , Daoyang Han , Hongxia Lu , Hongliang Xu , Hailong Wang , Rui Zhang , Linan An , Gang Shao
The low–temperature plastic forming ability of ceramics with complex structures is unsatisfied due to the strong covalent and ionic bonds, restricting their widespread applications. Herein, a technique is proposed for the ultra–fast plastic forming of zirconia ceramics using a low temperature and high electric field. The high electric field–assisted plastic forming temperature and rate are 1000 °C and 10 mm/min, respectively, which are much lower and faster than those of conventional plastic forming methods for ceramics. The deformed “Ω”–shape zirconia part exhibits a uniform microstructure without microcracks/cavities and a high hardness, demonstrating that the high electric field–assisted plastic forming technique enables the rapid fabrication of complex ceramic components with beneficial properties at low temperatures.
{"title":"Ultra–fast plastic forming of zirconia ceramics under a low temperature and high electric field","authors":"Rui Zhao , Chao Ma , Hongtian He , Ying Li , Daoyang Han , Hongxia Lu , Hongliang Xu , Hailong Wang , Rui Zhang , Linan An , Gang Shao","doi":"10.1016/j.jeurceramsoc.2024.117055","DOIUrl":"10.1016/j.jeurceramsoc.2024.117055","url":null,"abstract":"<div><div>The low–temperature plastic forming ability of ceramics with complex structures is unsatisfied due to the strong covalent and ionic bonds, restricting their widespread applications. Herein, a technique is proposed for the ultra–fast plastic forming of zirconia ceramics using a low temperature and high electric field. The high electric field–assisted plastic forming temperature and rate are 1000 °C and 10 mm/min, respectively, which are much lower and faster than those of conventional plastic forming methods for ceramics. The deformed “Ω”–shape zirconia part exhibits a uniform microstructure without microcracks/cavities and a high hardness, demonstrating that the high electric field–assisted plastic forming technique enables the rapid fabrication of complex ceramic components with beneficial properties at low temperatures.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 4","pages":"Article 117055"},"PeriodicalIF":5.8,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The sintering of uranium dioxide was investigated for humidified Ar/5 vol% H2 gas mixtures up to 1700 °C. Three relative humidity levels were used: 100, 1200 and 7500 vpm. The sintering map has been built. It is unique and independent of the thermo-atmospheric conditions of the sintering cycle. All samples have a ratio of around 2.00. Whatever the value of the relative humidity level of the sintering gas mixture, it is proposed that densification is controlled by volume diffusion of the uranium cations and that grain growth is controlled by the grain boundaries. An apparent activation energy for densification has been calculated. The parameters of a shortened sintering cycle are finally proposed. They allow a reduction of approximately 50 % in the cold-to-cold duration, compared to what is currently done in the context of the manufacture of uranium dioxide fuel pellets for PWR reactors.
{"title":"Revisiting the sintering of uranium dioxide","authors":"Kaythleen Torrente , Christelle Duguay , Franck Doreau , F. Lebreton , Guillaume Bernard-Granger","doi":"10.1016/j.jeurceramsoc.2024.117032","DOIUrl":"10.1016/j.jeurceramsoc.2024.117032","url":null,"abstract":"<div><div>The sintering of uranium dioxide was investigated for humidified Ar/5 vol% H<sub>2</sub> gas mixtures up to 1700 °C. Three relative humidity levels were used: 100, 1200 and 7500 vpm. The sintering map has been built. It is unique and independent of the thermo-atmospheric conditions of the sintering cycle. All samples have a <span><math><mrow><mi>O</mi><mo>/</mo><mi>U</mi></mrow></math></span> ratio of around 2.00. Whatever the value of the relative humidity level of the sintering gas mixture, it is proposed that densification is controlled by volume diffusion of the uranium cations and that grain growth is controlled by the grain boundaries. An apparent activation energy for densification has been calculated. The parameters of a shortened sintering cycle are finally proposed. They allow a reduction of approximately 50 % in the cold-to-cold duration, compared to what is currently done in the context of the manufacture of uranium dioxide fuel pellets for PWR reactors.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 3","pages":"Article 117032"},"PeriodicalIF":5.8,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-11-06DOI: 10.1016/j.jeurceramsoc.2024.117057
Jinyan Qi , Chenshuo Yuan , Hui Ye , Pengkai Shan , Shuiqing Li , Shoucheng He , Han Chen , Lin Ge , Yifeng Zheng
Double perovskite PrBaFe2O5+δ (PBF) is a promising cathode material for solid oxide fuel cell (SOFCs) due to the favorable catalytic activity and superior electrochemical stability. Herein, to further tailor the oxygen-ion transport kinetics and electrochemical performance, unlike the typical approach through using higher valence, non-transition metal In3+ ion doping is initially investigated to partially replace Fe3+/Fe4+ site, forming the compositions of PrBaFe2−xInxO5+δ (PBFInx, x = 0, 0.05, 0.1, and 0.15). Xray diffraction (XRD) analysis indicates that PBFInx exhibit satisfactory chemical and thermal compatibility with the gadolinia-doped ceria (GDC) electrolyte. Expectedly, the polarization resistance (Rp) of PBFIn0.1 cathode is decreased by approximately 40 % and an anode-supported single cell with PBFIn0.1 cathode yields a 36 % higher peak power density (PPD) at 800 °C compared to that of PBF. Moreover, the single cell using PBFIn0.1 as the cathode can be operated stably at 0.4 A cm−2 for more than 50 h without obvious performance degradation. In addition, the X-ray photoelectron spectroscopy (XPS) results confirm that the low-valence state In3+ introduced into PBF have a positive impact on the oxygen vacancy concentration and boost the oxygen reduction reaction (ORR) activity, thus significantly enhancing the electrochemical performance of the PBF cathode. The results show that the non-transition metal In3+ ion doping is an effective method to improve the performance of the PBF cathode for SOFCs.
{"title":"Tailoring the catalytic activity of PrBaFe2O5+δ cathode material with non-transition metal In-doping for solid oxide fuel cells","authors":"Jinyan Qi , Chenshuo Yuan , Hui Ye , Pengkai Shan , Shuiqing Li , Shoucheng He , Han Chen , Lin Ge , Yifeng Zheng","doi":"10.1016/j.jeurceramsoc.2024.117057","DOIUrl":"10.1016/j.jeurceramsoc.2024.117057","url":null,"abstract":"<div><div>Double perovskite PrBaFe<sub>2</sub>O<sub>5+δ</sub> (PBF) is a promising cathode material for solid oxide fuel cell (SOFCs) due to the favorable catalytic activity and superior electrochemical stability. Herein, to further tailor the oxygen-ion transport kinetics and electrochemical performance, unlike the typical approach through using higher valence, non-transition metal In<sup>3+</sup> ion doping is initially investigated to partially replace Fe<sup>3+</sup>/Fe<sup>4+</sup> site, forming the compositions of PrBaFe<sub>2−x</sub>In<sub>x</sub>O<sub>5+δ</sub> (PBFInx, x = 0, 0.05, 0.1, and 0.15). Xray diffraction (XRD) analysis indicates that PBFInx exhibit satisfactory chemical and thermal compatibility with the gadolinia-doped ceria (GDC) electrolyte. Expectedly, the polarization resistance (Rp) of PBFIn<sub>0.1</sub> cathode is decreased by approximately 40 % and an anode-supported single cell with PBFIn<sub>0.1</sub> cathode yields a 36 % higher peak power density (PPD) at 800 °C compared to that of PBF. Moreover, the single cell using PBFIn<sub>0.1</sub> as the cathode can be operated stably at 0.4 A cm<sup>−2</sup> for more than 50 h without obvious performance degradation. In addition, the X-ray photoelectron spectroscopy (XPS) results confirm that the low-valence state In<sup>3+</sup> introduced into PBF have a positive impact on the oxygen vacancy concentration and boost the oxygen reduction reaction (ORR) activity, thus significantly enhancing the electrochemical performance of the PBF cathode. The results show that the non-transition metal In<sup>3+</sup> ion doping is an effective method to improve the performance of the PBF cathode for SOFCs.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 3","pages":"Article 117057"},"PeriodicalIF":5.8,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-11-06DOI: 10.1016/j.jeurceramsoc.2024.117039
L.R.M. Toller-Nordström , O. Gavalda-Diaz , L. Gale , D.E.J. Armstrong , R.J. Nicholls
Ceramic matrix composites of silicon carbide fibres in a silicon carbide matrix with boron nitride interphase are promising candidates for replacing superalloys in the hottest part of aerospace engines, reducing the need for cooling and increasing the fuel efficiency. This needs a thorough understanding of how these materials degrade under high levels of stress combined with high temperatures in an oxidative environment. This work presents a detailed investigation of the degradation in the interphase and surrounding interfaces. Advanced electron microscopy and electron energy loss spectroscopy are used to extract information on the degradation process. It was found that silica and boria form along with a migration of silica into the interphase. At 1000 °C the degradation along the surface leads to early fracture at the surface and eventually complete fracture of the composite, lower temperature allows for the oxidation to reach the centre of the sample before complete failure.
碳化硅基体中的碳化硅纤维与氮化硼相间的陶瓷基复合材料有望在航空航天发动机最热的部分取代超合金，从而减少冷却需求并提高燃料效率。这就需要深入了解这些材料在氧化环境中如何在高应力和高温的双重作用下发生降解。这项研究对相间和周围界面的降解情况进行了详细调查。先进的电子显微镜和电子能量损失光谱被用来提取降解过程的信息。研究发现，二氧化硅和硼砂的形成伴随着二氧化硅向相间的迁移。在 1000 ° C 时，沿表面的降解导致表面早期断裂，最终复合材料完全断裂，而较低的温度可使氧化作用在完全破坏之前到达样品的中心。
{"title":"Detailed study of interphase degradation in SiC/BN/SiC ceramic matrix composites after elevated temperature tensile testing","authors":"L.R.M. Toller-Nordström , O. Gavalda-Diaz , L. Gale , D.E.J. Armstrong , R.J. Nicholls","doi":"10.1016/j.jeurceramsoc.2024.117039","DOIUrl":"10.1016/j.jeurceramsoc.2024.117039","url":null,"abstract":"<div><div>Ceramic matrix composites of silicon carbide fibres in a silicon carbide matrix with boron nitride interphase are promising candidates for replacing superalloys in the hottest part of aerospace engines, reducing the need for cooling and increasing the fuel efficiency. This needs a thorough understanding of how these materials degrade under high levels of stress combined with high temperatures in an oxidative environment. This work presents a detailed investigation of the degradation in the interphase and surrounding interfaces. Advanced electron microscopy and electron energy loss spectroscopy are used to extract information on the degradation process. It was found that silica and boria form along with a migration of silica into the interphase. At 1000 °C the degradation along the surface leads to early fracture at the surface and eventually complete fracture of the composite, lower temperature allows for the oxidation to reach the centre of the sample before complete failure.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 4","pages":"Article 117039"},"PeriodicalIF":5.8,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-05DOI: 10.1016/j.jeurceramsoc.2024.117035
Shahin Takht Firouzeh , Martin Abendroth , Tony Wetzig , Christos G. Aneziris , Bjoern Kiefer
The Brazilian disc test (BDT) and the ball-on-three-ball (B3B) test, both adapted for utilizing miniaturized specimens, are used to characterize the strength of ceramic filter materials made from carbon-bonded alumina (Al2O3-C) at temperatures up to 1500 °C. Conventionally manufactured Al2O3-C and environmentally friendly coal tar pitch-free variations of filter materials are investigated. To determine the fracture stresses and the Weibull distribution of the material’s strength, finite element models and the maximum likelihood method are used. Scanning electron microscopy of fracture surfaces gives insight into the microstructure of tested samples. The material strength of the pitch-free Al2O3-C was found to be inferior to the conventional alternative. The volume-related Weibull stress distributions revealed that the uniaxial strength of the conventional filter materials exhibited an increasing trend as temperature increased, which was contrary to the biaxial strength.
{"title":"Employing miniaturized test methods to determine high-temperature strength of carbon-bonded alumina","authors":"Shahin Takht Firouzeh , Martin Abendroth , Tony Wetzig , Christos G. Aneziris , Bjoern Kiefer","doi":"10.1016/j.jeurceramsoc.2024.117035","DOIUrl":"10.1016/j.jeurceramsoc.2024.117035","url":null,"abstract":"<div><div>The Brazilian disc test (BDT) and the ball-on-three-ball (B3B) test, both adapted for utilizing miniaturized specimens, are used to characterize the strength of ceramic filter materials made from carbon-bonded alumina (Al<sub>2</sub>O<sub>3</sub>-C) at temperatures up to 1500 °C. Conventionally manufactured Al<sub>2</sub>O<sub>3</sub>-C and environmentally friendly coal tar pitch-free variations of filter materials are investigated. To determine the fracture stresses and the Weibull distribution of the material’s strength, finite element models and the maximum likelihood method are used. Scanning electron microscopy of fracture surfaces gives insight into the microstructure of tested samples. The material strength of the pitch-free Al<sub>2</sub>O<sub>3</sub>-C was found to be inferior to the conventional alternative. The volume-related Weibull stress distributions revealed that the uniaxial strength of the conventional filter materials exhibited an increasing trend as temperature increased, which was contrary to the biaxial strength.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 3","pages":"Article 117035"},"PeriodicalIF":5.8,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-05DOI: 10.1016/j.jeurceramsoc.2024.117054
Yabin Zhu , Lijuan Niu , Jianlong Chai , Ji Wang , Peng Jin , Boyu Chen , Dong Wang , Yuanfei Li , Tongmin Zhang , Tielong Shen , Cunfeng Yao , Zhiguang Wang
Ceramic composites with high temperature strengths and low neutron cross-sections are promising candidates for core materials in advanced nuclear systems. In present work, SiC-20 vol% ZrC composites were irradiated with 500 keV He-ions at 25, 500 and 800 °C to evaluate the effect of irradiation temperature on the structural damage and bubble evolution in ceramic composites. XRD and Raman spectra analysis give that the irradiation resulted in structural damages of both SiC and ZrC. TEM observations reveal the formation of helium bubbles and defect clusters after irradiation. Moreover, the occurrence of micro-cracks in ZrC grains and amorphization of SiC are observed for the samples irradiated at room temperature. Nanoindentation test showed that there is irradiation induced hardening or softening of the composites which depends on the irradiation temperature or fluence. The correlation between microstructural evolution and mechanical properties response is discussed.
具有高温强度和低中子截面的陶瓷复合材料有望成为先进核系统的核心材料。在本研究中，SiC-20 Vol% ZrC 复合材料分别在 25、500 和 800 ℃ 下接受了 500 keV He 离子的辐照，以评估辐照温度对陶瓷复合材料结构损伤和气泡演化的影响。XRD 和拉曼光谱分析表明，辐照导致碳化硅和碳化锆的结构损坏。TEM 观察显示，辐照后形成了氦气泡和缺陷簇。此外，在室温下辐照的样品还观察到 ZrC 晶粒出现微裂纹和 SiC 非晶化现象。纳米压痕测试表明，复合材料存在辐照诱导的硬化或软化现象，这取决于辐照温度或能量。本文讨论了微观结构演变与机械性能响应之间的相关性。
{"title":"Structural damage and bubble evolution in SiC-ZrC composite irradiated with 500 keV He-ions at various temperatures","authors":"Yabin Zhu , Lijuan Niu , Jianlong Chai , Ji Wang , Peng Jin , Boyu Chen , Dong Wang , Yuanfei Li , Tongmin Zhang , Tielong Shen , Cunfeng Yao , Zhiguang Wang","doi":"10.1016/j.jeurceramsoc.2024.117054","DOIUrl":"10.1016/j.jeurceramsoc.2024.117054","url":null,"abstract":"<div><div>Ceramic composites with high temperature strengths and low neutron cross-sections are promising candidates for core materials in advanced nuclear systems. In present work, SiC-20 vol% ZrC composites were irradiated with 500 keV He-ions at 25, 500 and 800 °C to evaluate the effect of irradiation temperature on the structural damage and bubble evolution in ceramic composites. XRD and Raman spectra analysis give that the irradiation resulted in structural damages of both SiC and ZrC. TEM observations reveal the formation of helium bubbles and defect clusters after irradiation. Moreover, the occurrence of micro-cracks in ZrC grains and amorphization of SiC are observed for the samples irradiated at room temperature. Nanoindentation test showed that there is irradiation induced hardening or softening of the composites which depends on the irradiation temperature or fluence. The correlation between microstructural evolution and mechanical properties response is discussed.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 3","pages":"Article 117054"},"PeriodicalIF":5.8,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 : 2024-11-05DOI: 10.1016/j.jeurceramsoc.2024.117056
Xianqi Cao , Kunlong Zhao , Laiming Song , Jianxin Tang , Chunhong Zhang , Jianwei Bai , Lijia Liu , Wenxin Cao , Yize Wu , Jinlong Xue , Yun Zhang
Si3N4 ceramics are widely employed in the aerospace and automotive sectors owing to exceptional mechanical performances, anti-oxidant nature, and corrosion resistance properties. However, their brittleness makes manufacturing complex components challenging, while the intricate nature of welding restricts its use. A Si3N4 ceramic adhesive joint capable of withstanding high-temperature conditions was formed under ambient conditions. Polycarbosilane was introduced into the phosphate adhesive to improve high-temperature thermal matching between the adhesive and substrate, At 600 and 800 ℃, the compressive shear strength increased by 25 % and 83 %, respectively. After 48 h at 1000 ℃, the compressive shear strength was 8.6 MPa, indicating excellent oxidation resistance. The adhesive penetrated the matrix pores under capillary action, forming network bonding, and an interfacial reaction generated Si5AlON7, buffering thermal stress. This represents the first phosphate adhesive for bonding Si3N4 ceramics, demonstrating excellent forming capabilities, with bond strengths comparable to that of conventional welds, showing high potential for engineering applications.
{"title":"Polycarbosilane-modified phosphate adhesives for porous Si3N4 ceramic pressure-free bonding at high temperatures","authors":"Xianqi Cao , Kunlong Zhao , Laiming Song , Jianxin Tang , Chunhong Zhang , Jianwei Bai , Lijia Liu , Wenxin Cao , Yize Wu , Jinlong Xue , Yun Zhang","doi":"10.1016/j.jeurceramsoc.2024.117056","DOIUrl":"10.1016/j.jeurceramsoc.2024.117056","url":null,"abstract":"<div><div>Si<sub>3</sub>N<sub>4</sub> ceramics are widely employed in the aerospace and automotive sectors owing to exceptional mechanical performances, anti-oxidant nature, and corrosion resistance properties. However, their brittleness makes manufacturing complex components challenging, while the intricate nature of welding restricts its use. A Si<sub>3</sub>N<sub>4</sub> ceramic adhesive joint capable of withstanding high-temperature conditions was formed under ambient conditions. Polycarbosilane was introduced into the phosphate adhesive to improve high-temperature thermal matching between the adhesive and substrate, At 600 and 800 ℃, the compressive shear strength increased by 25 % and 83 %, respectively. After 48 h at 1000 ℃, the compressive shear strength was 8.6 MPa, indicating excellent oxidation resistance. The adhesive penetrated the matrix pores under capillary action, forming network bonding, and an interfacial reaction generated Si<sub>5</sub>AlON<sub>7</sub>, buffering thermal stress. This represents the first phosphate adhesive for bonding Si<sub>3</sub>N<sub>4</sub> ceramics, demonstrating excellent forming capabilities, with bond strengths comparable to that of conventional welds, showing high potential for engineering applications.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 4","pages":"Article 117056"},"PeriodicalIF":5.8,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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