Pengcheng Hao, Xiaojun Lv, Zexun Han, Yongcong Wu, Xuan Tan
Air oxidation is the main cause of the excessive consumption of prebaked anodes, which not only wastes carbon resources but also increases carbon emissions. In this study, a quasi-molten coating with self-healing for prebaked anode by using the slurry method was proposed. This coating utilizes the viscous molten liquid phases to bond the carbon anode, absorbs thermal stress, insulates the carbon anode from the air, and provides self-healing capabilities at elevated temperatures, while the solid phase provides toughening properties. A series of oxidation experiments have shown that the coating has superior oxidation resistance than coatings reported in the literature.
{"title":"The oxidation resistance study of a novel quasi-molten coating for the prebaked anode","authors":"Pengcheng Hao, Xiaojun Lv, Zexun Han, Yongcong Wu, Xuan Tan","doi":"10.1111/ijac.14864","DOIUrl":"10.1111/ijac.14864","url":null,"abstract":"<p>Air oxidation is the main cause of the excessive consumption of prebaked anodes, which not only wastes carbon resources but also increases carbon emissions. In this study, a quasi-molten coating with self-healing for prebaked anode by using the slurry method was proposed. This coating utilizes the viscous molten liquid phases to bond the carbon anode, absorbs thermal stress, insulates the carbon anode from the air, and provides self-healing capabilities at elevated temperatures, while the solid phase provides toughening properties. A series of oxidation experiments have shown that the coating has superior oxidation resistance than coatings reported in the literature.</p>","PeriodicalId":13903,"journal":{"name":"International Journal of Applied Ceramic Technology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141866062","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}
Xiongwei Dong, Fenglan Han, Ning Li, Fuyuan Dong, Haipeng Liu, Yu Neng, Maohui Li
High‐strength foamed ceramics were synthesized employing silicon‐manganese slag (SM) and fluorgypsum (FG) as raw materials, with SiC serving as the foaming agent. Investigations into the influence of firing temperature and FG content on the phase structure, microstructure, and physical properties of foam ceramics were conducted. Characterization of the samples was performed through X‐ray diffraction and scanning electron microscopy. Results indicate that an increase in FG content lowers the matrix melting point, promotes crystal growth, enhances compressive strength, and forms a uniform pore structure. At an FG content of 11%, ceramics prepared at a firing temperature of 1130°C exhibit a density of 0.56 g/cm3, porosity of 78.45%, and compressive strength of 3.05 MPa. This study explores the use of FG as a cost‐effective alternative to borax, demonstrating a sustainable approach for foam ceramics preparation using silicomanganese slag and FG synergy.
{"title":"Preparation and characterization of foamed ceramics from silicomanganese and fluorgypsum waste","authors":"Xiongwei Dong, Fenglan Han, Ning Li, Fuyuan Dong, Haipeng Liu, Yu Neng, Maohui Li","doi":"10.1111/ijac.14850","DOIUrl":"https://doi.org/10.1111/ijac.14850","url":null,"abstract":"High‐strength foamed ceramics were synthesized employing silicon‐manganese slag (SM) and fluorgypsum (FG) as raw materials, with SiC serving as the foaming agent. Investigations into the influence of firing temperature and FG content on the phase structure, microstructure, and physical properties of foam ceramics were conducted. Characterization of the samples was performed through X‐ray diffraction and scanning electron microscopy. Results indicate that an increase in FG content lowers the matrix melting point, promotes crystal growth, enhances compressive strength, and forms a uniform pore structure. At an FG content of 11%, ceramics prepared at a firing temperature of 1130°C exhibit a density of 0.56 g/cm<jats:sup>3</jats:sup>, porosity of 78.45%, and compressive strength of 3.05 MPa. This study explores the use of FG as a cost‐effective alternative to borax, demonstrating a sustainable approach for foam ceramics preparation using silicomanganese slag and FG synergy.","PeriodicalId":13903,"journal":{"name":"International Journal of Applied Ceramic Technology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141866061","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}
Elnaz Irom, Mohammad Zakeri, Mansour Razavi, Mohammad Farvizi
This study investigated the influences of WC and HfB2 additives along with SiC reinforcement (with various particle sizes) on densification, microstructure, and mechanical properties of ZrB2–SiC composites. The results showed that WC and HfB2 addition formed a solid solution of (Zr,W,Hf)B2 with a core–shell structure, whereas the remaining WC transformed into WB. Moreover, nano‐sized SiC caused a much better impact on densification compared to micro‐sized SiC. A small fraction of localized phases like ZrC, HfB, and (Hf,Zr)C in the form of solid solution were also formed. The maximum room temperature flexural strength and the fracture toughness of the sample containing 150 nm SiC and 8.9 wt.% WB were measured to be 682 17 MPa and 6.5 .3 MPa m1/2, respectively.
{"title":"ZrB2‐based ultrahigh‐temperature ceramic with various SiC particle size: Microstructure, thermodynamical behavior, and mechanical properties","authors":"Elnaz Irom, Mohammad Zakeri, Mansour Razavi, Mohammad Farvizi","doi":"10.1111/ijac.14855","DOIUrl":"https://doi.org/10.1111/ijac.14855","url":null,"abstract":"This study investigated the influences of WC and HfB<jats:sub>2</jats:sub> additives along with SiC reinforcement (with various particle sizes) on densification, microstructure, and mechanical properties of ZrB<jats:sub>2</jats:sub>–SiC composites. The results showed that WC and HfB<jats:sub>2</jats:sub> addition formed a solid solution of (Zr,W,Hf)B<jats:sub>2</jats:sub> with a core–shell structure, whereas the remaining WC transformed into WB. Moreover, nano‐sized SiC caused a much better impact on densification compared to micro‐sized SiC. A small fraction of localized phases like ZrC, HfB, and (Hf,Zr)C in the form of solid solution were also formed. The maximum room temperature flexural strength and the fracture toughness of the sample containing 150 nm SiC and 8.9 wt.% WB were measured to be 682 17 MPa and 6.5 .3 MPa m<jats:sup>1/2</jats:sup>, respectively.","PeriodicalId":13903,"journal":{"name":"International Journal of Applied Ceramic Technology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141778520","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}
Panpan Tang, Yangkai Xiong, Lei Huang, Zhiqiang Fang, Hao Jiang, Guoqing Wang
By using tartaric acid (TA) as a wet‐method modifier to modify steel slag powder (SS), it is helpful to reduce the content of free calcium oxide (f‐CaO) in SS and further improve the mechanical properties and soundness of SS as supplementing cementitious materials (SCM) in the mortar. The results indicate that with the addition of 2 wt% of TA, the number of large particles bigger than 45 µm in the SS decreased, resulting in predominantly smaller particles smaller than 45 µm. While the specific surface area increased from 417 to 704 m2/kg, the water consumption at standard consistency was significantly reduced. The soundness of the paste SS as SCM had improved including the f‐CaO content decreased from 4.81% to 0.95%, and the Le Chatelier expansion reduced from 4.5 to 1.5 mm. The mechanical properties were significantly enhanced, with the flexural strength increasing from 5.6 to 7.8 MPa, and the compressive strength rising from 38.8 to 52.7 MPa. After 28 days of curing in water, the hydration products of the mortar are hydrated calcium silicate (C‐S‐H), calcium hydroxide (CH), and calcium carbonate (CaCO3).
{"title":"Properties of tartaric acid modified steel slag as supplementing cementitious materials","authors":"Panpan Tang, Yangkai Xiong, Lei Huang, Zhiqiang Fang, Hao Jiang, Guoqing Wang","doi":"10.1111/ijac.14872","DOIUrl":"https://doi.org/10.1111/ijac.14872","url":null,"abstract":"By using tartaric acid (TA) as a wet‐method modifier to modify steel slag powder (SS), it is helpful to reduce the content of free calcium oxide (f‐CaO) in SS and further improve the mechanical properties and soundness of SS as supplementing cementitious materials (SCM) in the mortar. The results indicate that with the addition of 2 wt% of TA, the number of large particles bigger than 45 µm in the SS decreased, resulting in predominantly smaller particles smaller than 45 µm. While the specific surface area increased from 417 to 704 m<jats:sup>2</jats:sup>/kg, the water consumption at standard consistency was significantly reduced. The soundness of the paste SS as SCM had improved including the f‐CaO content decreased from 4.81% to 0.95%, and the Le Chatelier expansion reduced from 4.5 to 1.5 mm. The mechanical properties were significantly enhanced, with the flexural strength increasing from 5.6 to 7.8 MPa, and the compressive strength rising from 38.8 to 52.7 MPa. After 28 days of curing in water, the hydration products of the mortar are hydrated calcium silicate (C‐S‐H), calcium hydroxide (CH), and calcium carbonate (CaCO<jats:sub>3</jats:sub>).","PeriodicalId":13903,"journal":{"name":"International Journal of Applied Ceramic Technology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141778521","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}
Feixiang Ma, Guoqi Liu, Qiang Gu, Yi Zhang, Hongxia Li
In this study, the reaction interfaces of four kinds of oxide refractories (corundum, spinel, mullite, and zirconia) with lanthanum oxide (La2O3) and lanthanum aluminate (LaAlO3) under different atmospheres at high temperatures (1550°C) were analyzed. The results show that the four oxides have a strong reaction with La2O3, and the corresponding rare earth aluminate, rare earth silicate, and rare earth zirconate are formed respectively. The reaction with LaAlO3 is weak, and almost no reaction occurs. Mullite has poor structural stability in a high‐temperature reduction atmosphere, easy decomposition, and strong reaction with La2O3. This study provides an important reference for the study of the reaction mechanism between rare earth steel and lining materials and the research and development of special lining materials for rare earth steel.
{"title":"Study on reaction interface of carbon‐free oxide‐based refractories with lanthanum oxide and lanthanum aluminate","authors":"Feixiang Ma, Guoqi Liu, Qiang Gu, Yi Zhang, Hongxia Li","doi":"10.1111/ijac.14873","DOIUrl":"https://doi.org/10.1111/ijac.14873","url":null,"abstract":"In this study, the reaction interfaces of four kinds of oxide refractories (corundum, spinel, mullite, and zirconia) with lanthanum oxide (La<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>) and lanthanum aluminate (LaAlO<jats:sub>3</jats:sub>) under different atmospheres at high temperatures (1550°C) were analyzed. The results show that the four oxides have a strong reaction with La<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>, and the corresponding rare earth aluminate, rare earth silicate, and rare earth zirconate are formed respectively. The reaction with LaAlO<jats:sub>3</jats:sub> is weak, and almost no reaction occurs. Mullite has poor structural stability in a high‐temperature reduction atmosphere, easy decomposition, and strong reaction with La<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>. This study provides an important reference for the study of the reaction mechanism between rare earth steel and lining materials and the research and development of special lining materials for rare earth steel.","PeriodicalId":13903,"journal":{"name":"International Journal of Applied Ceramic Technology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141778522","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}
Utilizing marine waste and resources for eco‐friendly building materials is pivotal in promoting sustainable development in island and coastal construction industries. Among the potential alternatives, coral sand as well as sea sand stands out as a promising material. This research seeks to explore the potential of coral/sea sand as a fine aggregate in the creation of environmentally sustainable marine engineered geopolymer composites. An assessment was conducted on the influence of varying proportions of coral sand, meant as a substitute for sea sand, on the flowability, drying shrinkage, mechanical properties, and microstructure of the marine engineered geopolymer composites. The findings indicate that as coral sand replaces sea sand, flowability and drying shrinkage decrease, while compressive strength experiences an initial rise followed by a decline. Encouragingly, a combination of coral and sea sands enhances tensile ductility. Overall, a 20 wt.% coral sand mixture yields optimal results, with the compressive strength is 54.4 Mpa and the tensile strain capacity is 2.397% after 28 days. Moreover, microscopic tests reveal changes in hydration products and pore structure. Our research delves into the potential of coral/sea sand as a fine aggregate in the creation of environmentally sustainable marine engineered geopolymer composites.
{"title":"Sea/coral sand in marine engineered geopolymer composites: Engineering, mechanical, and microstructure properties","authors":"Xiaochun Fan, Jiakun Zhu, Xu Gao","doi":"10.1111/ijac.14874","DOIUrl":"https://doi.org/10.1111/ijac.14874","url":null,"abstract":"Utilizing marine waste and resources for eco‐friendly building materials is pivotal in promoting sustainable development in island and coastal construction industries. Among the potential alternatives, coral sand as well as sea sand stands out as a promising material. This research seeks to explore the potential of coral/sea sand as a fine aggregate in the creation of environmentally sustainable marine engineered geopolymer composites. An assessment was conducted on the influence of varying proportions of coral sand, meant as a substitute for sea sand, on the flowability, drying shrinkage, mechanical properties, and microstructure of the marine engineered geopolymer composites. The findings indicate that as coral sand replaces sea sand, flowability and drying shrinkage decrease, while compressive strength experiences an initial rise followed by a decline. Encouragingly, a combination of coral and sea sands enhances tensile ductility. Overall, a 20 wt.% coral sand mixture yields optimal results, with the compressive strength is 54.4 Mpa and the tensile strain capacity is 2.397% after 28 days. Moreover, microscopic tests reveal changes in hydration products and pore structure. Our research delves into the potential of coral/sea sand as a fine aggregate in the creation of environmentally sustainable marine engineered geopolymer composites.","PeriodicalId":13903,"journal":{"name":"International Journal of Applied Ceramic Technology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141778524","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}
Digital image correlation (DIC) method was employed to analyze the dynamic bending of a metallized Si3N4 substrate in thermal cycles ranging from −40°C to 250°C. The substrate was monitored by DIC over several consecutive cycles, spanning from 0 to 2501. Three DIC measurement intervals, specifically during 999–1001, 1999–2001, and 2499–2501 cycles, were selected to analyze the bending behavior in response to temperature fluctuations. By the scanning acoustic microscope (SAM), the substrate revealed negligible delamination after 1001 cycles, light delamination after 2001 cycles, and serious delamination post‐2501 cycles. The dynamic bending remained unchanged during 999–1001 cycles. A curve with a negative bending was observed during 1999–2001 cycles, with a peak curvature of .024 mm−1 at −40°C; the negative bending intensified with a curvature reaching .050 mm−1 at −40°C during 2499–2501 cycles. The bending curve then decreased during the heating phase and returned to a non‐bent state at elevated temperatures. The bending curve reversed to positive at 250°C during thermal cycles from 2499 to 2501. The bending behavior throughout thermal cycles was discussed in relation to the asymmetric delamination observed on both sides of the substrate, as well as the distribution of delamination.
{"title":"Dynamic bending analysis of metallized silicon nitride substrate during thermal cycling via digital image correlation","authors":"Minh Chu Ngo, Hiroyuki Miyazaki, Kiyoshi Hirao, Tatsuki Ohji, Manabu Fukushima","doi":"10.1111/ijac.14875","DOIUrl":"https://doi.org/10.1111/ijac.14875","url":null,"abstract":"Digital image correlation (DIC) method was employed to analyze the dynamic bending of a metallized Si<jats:sub>3</jats:sub>N<jats:sub>4</jats:sub> substrate in thermal cycles ranging from −40°C to 250°C. The substrate was monitored by DIC over several consecutive cycles, spanning from 0 to 2501. Three DIC measurement intervals, specifically during 999–1001, 1999–2001, and 2499–2501 cycles, were selected to analyze the bending behavior in response to temperature fluctuations. By the scanning acoustic microscope (SAM), the substrate revealed negligible delamination after 1001 cycles, light delamination after 2001 cycles, and serious delamination post‐2501 cycles. The dynamic bending remained unchanged during 999–1001 cycles. A curve with a negative bending was observed during 1999–2001 cycles, with a peak curvature of .024 mm<jats:sup>−1</jats:sup> at −40°C; the negative bending intensified with a curvature reaching .050 mm<jats:sup>−1</jats:sup> at −40°C during 2499–2501 cycles. The bending curve then decreased during the heating phase and returned to a non‐bent state at elevated temperatures. The bending curve reversed to positive at 250°C during thermal cycles from 2499 to 2501. The bending behavior throughout thermal cycles was discussed in relation to the asymmetric delamination observed on both sides of the substrate, as well as the distribution of delamination.","PeriodicalId":13903,"journal":{"name":"International Journal of Applied Ceramic Technology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141778523","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}
Yaxuan Wang, Junzhan Zhang, Jianying Gao, Zhaopeng Yang
In the field of ceramics, mullite has drawn plenty of attention due to its low thermal expansion and thermal conductivity as well as its high chemical stability and creep resistance. This work reported the mineral phase, liquid phase, and microstructure evolution of the sintered mullite, using coal‐series kaolin as the raw material and potash feldspar as well as phosphorus pentoxide as additives. The effects of K2O and P2O5 on the content and viscosity of the liquid phase in mullite were calculated using FactSage 8.1. The results showed that the introduction of K2O could inhibit the formation of cristobalite effectively. Adding K2O and P2O5 improved the content of the liquid phase formed during the calcination process. After introducing K2O and P2O5, mullite developed acicular and columnar structures, with average lengths of 9.76 and 7.97 µm, respectively. Furthermore, introducing K2O and P2O5 improved the physical properties of mullite significantly.
{"title":"Modification of liquid phase and microstructure of sintered mullite by different additives","authors":"Yaxuan Wang, Junzhan Zhang, Jianying Gao, Zhaopeng Yang","doi":"10.1111/ijac.14860","DOIUrl":"https://doi.org/10.1111/ijac.14860","url":null,"abstract":"In the field of ceramics, mullite has drawn plenty of attention due to its low thermal expansion and thermal conductivity as well as its high chemical stability and creep resistance. This work reported the mineral phase, liquid phase, and microstructure evolution of the sintered mullite, using coal‐series kaolin as the raw material and potash feldspar as well as phosphorus pentoxide as additives. The effects of K<jats:sub>2</jats:sub>O and P<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub> on the content and viscosity of the liquid phase in mullite were calculated using FactSage 8.1. The results showed that the introduction of K<jats:sub>2</jats:sub>O could inhibit the formation of cristobalite effectively. Adding K<jats:sub>2</jats:sub>O and P<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub> improved the content of the liquid phase formed during the calcination process. After introducing K<jats:sub>2</jats:sub>O and P<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub>, mullite developed acicular and columnar structures, with average lengths of 9.76 and 7.97 µm, respectively. Furthermore, introducing K<jats:sub>2</jats:sub>O and P<jats:sub>2</jats:sub>O<jats:sub>5</jats:sub> improved the physical properties of mullite significantly.","PeriodicalId":13903,"journal":{"name":"International Journal of Applied Ceramic Technology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141741309","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}
Walter Harrer, Manuel Gruber, Verena Melcher, Anton Tilz, Michael Engelmayer, Andreas Wimmer, Raul Bermejo
Large gas engines are typically applied to compensate for peak loads and grid instabilities in the electric power supply. A key component of these engines is the spark plug. Because of the harsh conditions encountered in their use, the spark plug electrodes are subject to significant wear. Conventional electrodes are expensive due to the precious metal alloys they contain. As an alternative, ceramic materials from the groups of silicide, carbides, and nitrides were selected for preliminary experiments that investigate functional as well as mechanical properties and wear behavior. Because of the harsh conditions during operation, the new materials must have a high melting temperature, good thermal shock resistance, high thermal conductivity, and high corrosion/oxidation resistance as well as high density. It was found that the mechanical and thermomechanical properties of certain ceramic candidates are sufficient for application as spark plug electrodes. Furthermore, the chosen ceramic materials achieve an adequate performance in terms of secondary voltage trace and ignition behavior. However, wear resistance may not be sufficient for service times longer than the service time of existing spark plugs and further research is still necessary before ceramic electrodes may be established as a commercial alternative to existing electrodes.
{"title":"Ceramic materials as an alternative for conventional spark plug electrodes","authors":"Walter Harrer, Manuel Gruber, Verena Melcher, Anton Tilz, Michael Engelmayer, Andreas Wimmer, Raul Bermejo","doi":"10.1111/ijac.14865","DOIUrl":"10.1111/ijac.14865","url":null,"abstract":"<p>Large gas engines are typically applied to compensate for peak loads and grid instabilities in the electric power supply. A key component of these engines is the spark plug. Because of the harsh conditions encountered in their use, the spark plug electrodes are subject to significant wear. Conventional electrodes are expensive due to the precious metal alloys they contain. As an alternative, ceramic materials from the groups of silicide, carbides, and nitrides were selected for preliminary experiments that investigate functional as well as mechanical properties and wear behavior. Because of the harsh conditions during operation, the new materials must have a high melting temperature, good thermal shock resistance, high thermal conductivity, and high corrosion/oxidation resistance as well as high density. It was found that the mechanical and thermomechanical properties of certain ceramic candidates are sufficient for application as spark plug electrodes. Furthermore, the chosen ceramic materials achieve an adequate performance in terms of secondary voltage trace and ignition behavior. However, wear resistance may not be sufficient for service times longer than the service time of existing spark plugs and further research is still necessary before ceramic electrodes may be established as a commercial alternative to existing electrodes.</p>","PeriodicalId":13903,"journal":{"name":"International Journal of Applied Ceramic Technology","volume":null,"pages":null},"PeriodicalIF":1.8,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/ijac.14865","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141741307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, an Al2O3‐based ceramic pastes with high solid content and low viscosity for photocuring was prepared. The effects of TiO2/Yb2O3 binary sintering aid on the rheological properties, curing behavior, and bending strength of the sintered parts were systematically investigated. Ceramic samples with an intact surface and no defects were prepared through debinding in various atmospheres followed by pressure‐less sintering at 1600°C. The bending strength of the sintered material was 329 MPa, which represents a 231% increase compared to the bending strength of 99.4 MPa for pure Al2O3 ceramic material prepared using the same process, with the highest recorded bending strength reaching 478.47 MPa. Scanning electron microscopy and X‐ray diffraction analyses revealed that the binary sintering aid acts as a bridge between grains by forming a solid solution with Al2O3 powder at high temperatures, which decreased the pore size and number between Al2O3 ceramic grains, thereby enhancing the bending strength of the ceramics. The prepared ceramic pastes is expected to meet the manufacturing requirements of high‐performance ceramic substrates and accelerate the development of high‐performance ceramic substrate processing technology.
{"title":"The effect of TiO2/Yb2O3 binary sintering aids on the properties of UV‐cured Al2O3‐based ceramics","authors":"Xinyu Miao, Shuangyu Liu, Ping Lu, Hongtao Chu, Fulong Zhang, Chuanjin Huang, Liyan Wang","doi":"10.1111/ijac.14861","DOIUrl":"https://doi.org/10.1111/ijac.14861","url":null,"abstract":"In this study, an Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>‐based ceramic pastes with high solid content and low viscosity for photocuring was prepared. The effects of TiO<jats:sub>2</jats:sub>/Yb<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> binary sintering aid on the rheological properties, curing behavior, and bending strength of the sintered parts were systematically investigated. Ceramic samples with an intact surface and no defects were prepared through debinding in various atmospheres followed by pressure‐less sintering at 1600°C. The bending strength of the sintered material was 329 MPa, which represents a 231% increase compared to the bending strength of 99.4 MPa for pure Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> ceramic material prepared using the same process, with the highest recorded bending strength reaching 478.47 MPa. Scanning electron microscopy and X‐ray diffraction analyses revealed that the binary sintering aid acts as a bridge between grains by forming a solid solution with Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> powder at high temperatures, which decreased the pore size and number between Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> ceramic grains, thereby enhancing the bending strength of the ceramics. The prepared ceramic pastes is expected to meet the manufacturing requirements of high‐performance ceramic substrates and accelerate the development of high‐performance ceramic substrate processing technology.","PeriodicalId":13903,"journal":{"name":"International Journal of Applied Ceramic Technology","volume":null,"pages":null},"PeriodicalIF":2.1,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141741312","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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