Pub Date : 2025-01-04DOI: 10.1016/j.jeurceramsoc.2025.117186
Ankang Lu , Shaobai Sang , Guangyang Wang , Qinghu Wang , Yawei Li , Heng Wang , Tianbin Zhu , Xin Wang
Doping with transition metal ions can effectively improve the infrared performance of spinel materials; however, the high cost restricts its large-scale industrial application. Motivated by this, MgFe2O4 doping with in-situ generated Fe2+ was prepared by adjusting the sintering conditions. The influence of various sintering temperatures and atmospheres on the Fe2+ content was investigated, along with the effects of different Fe2+ doping levels on the infrared radiation properties of MgFe2O4. The mechanisms of in-situ formation of Fe2+ and Fe2+ doping in enhancing the infrared radiation properties of MgFe2O4 were discussed. Specifically, the specimen sintered in a reducing atmosphere at 1500 ℃ has the highest Fe2+ content, and also exhibit the highest average infrared emissivity in the 0.8–2.5 μm and 2.5–10 μm bands, which are 0.826 and 0.849, respectively.
{"title":"Enhanced infrared radiation properties of MgFe2O4 doping with in-situ generated Fe2+ by adjusting the sintering temperature and atmosphere","authors":"Ankang Lu , Shaobai Sang , Guangyang Wang , Qinghu Wang , Yawei Li , Heng Wang , Tianbin Zhu , Xin Wang","doi":"10.1016/j.jeurceramsoc.2025.117186","DOIUrl":"10.1016/j.jeurceramsoc.2025.117186","url":null,"abstract":"<div><div>Doping with transition metal ions can effectively improve the infrared performance of spinel materials; however, the high cost restricts its large-scale industrial application. Motivated by this, MgFe<sub>2</sub>O<sub>4</sub> doping with <em>in-situ</em> generated Fe<sup>2+</sup> was prepared by adjusting the sintering conditions. The influence of various sintering temperatures and atmospheres on the Fe<sup>2+</sup> content was investigated, along with the effects of different Fe<sup>2+</sup> doping levels on the infrared radiation properties of MgFe<sub>2</sub>O<sub>4</sub>. The mechanisms of <em>in-situ</em> formation of Fe<sup>2+</sup> and Fe<sup>2+</sup> doping in enhancing the infrared radiation properties of MgFe<sub>2</sub>O<sub>4</sub> were discussed. Specifically, the specimen sintered in a reducing atmosphere at 1500 ℃ has the highest Fe<sup>2+</sup> content, and also exhibit the highest average infrared emissivity in the 0.8–2.5 μm and 2.5–10 μm bands, which are 0.826 and 0.849, respectively.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 6","pages":"Article 117186"},"PeriodicalIF":5.8,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143156931","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 : 2025-01-04DOI: 10.1016/j.jeurceramsoc.2025.117185
Shixuan Wang , Yangwei Zhang , Ying Long , Hua-Tay Lin
Tungsten diboride (WB₂) exhibits excellent catalytic activity and stability in the hydrogen evolution reaction (HER) of water electrolysis, which are found to be closely related to the processing method of the electrode. In the present work, flake-like WB₂ powder was used to prepare self-supported electrodes through spark plasma sintering (SPS) at 750, 800, and 1600 °C, respectively, as well as cold isostatic pressing (CIP), with the electrode prepared by drop-casting from powder direction. The results showed that, in an acidic medium, the sample sintered at 750 °C exhibited an overpotential of 141.6 mV at 10 mA/cm², with a corresponding Tafel slope of 42.1 mV/dec, which demonstrated a high catalytic activity. In addition, the experimental results showed that the WB₂ particles bonded together to form a porous network structure after SPS low-temperature sintering, resulting in a high density of actively catalytic sites, reduced electron transfer impedance, and exceptional long-term stability.
{"title":"Electrocatalytic activity of WB2 electrodes for hydrogen evolution reaction prepared by different methods","authors":"Shixuan Wang , Yangwei Zhang , Ying Long , Hua-Tay Lin","doi":"10.1016/j.jeurceramsoc.2025.117185","DOIUrl":"10.1016/j.jeurceramsoc.2025.117185","url":null,"abstract":"<div><div>Tungsten diboride (WB₂) exhibits excellent catalytic activity and stability in the hydrogen evolution reaction (HER) of water electrolysis, which are found to be closely related to the processing method of the electrode. In the present work, flake-like WB₂ powder was used to prepare self-supported electrodes through spark plasma sintering (SPS) at 750, 800, and 1600 °C, respectively, as well as cold isostatic pressing (CIP), with the electrode prepared by drop-casting from powder direction. The results showed that, in an acidic medium, the sample sintered at 750 °C exhibited an overpotential of 141.6 mV at 10 mA/cm², with a corresponding Tafel slope of 42.1 mV/dec, which demonstrated a high catalytic activity. In addition, the experimental results showed that the WB₂ particles bonded together to form a porous network structure after SPS low-temperature sintering, resulting in a high density of actively catalytic sites, reduced electron transfer impedance, and exceptional long-term stability.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 6","pages":"Article 117185"},"PeriodicalIF":5.8,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143156929","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 : 2025-01-03DOI: 10.1016/j.jeurceramsoc.2024.117164
Dong Han , Guangwu Fang , Haoxiang Wang , Jinling Gao , Jiagui Liu , Tao Wu , Xiguang Gao , Yingdong Song
Dynamic tensile experiments of unidirectional (UD) SiC/PyC/SiC composites and SiC fiber bundles were performed using a Kolsky tension bar test system. Typical failure characteristics of UD ceramic matrix composites (CMCs), including matrix crack spacing, fiber pull-outs, matrix fracture surfaces and fiber fracture surfaces, were observed through optical and scanning electron microscopes. By combining micro-damage characteristics with mechanical behavior, we analyzed the dynamic damage mechanisms of UD-CMCs. Based on the test results, the dynamic loading effects on micro-mechanical parameters and their subsequent impact on the macro composite were determined. Finally, with these validated micro-parameters, we developed a rate-dependent constitutive model for UD-CMCs.
{"title":"Dynamic tensile behavior of unidirectional CVI SiCf/SiC composites with PyC interface","authors":"Dong Han , Guangwu Fang , Haoxiang Wang , Jinling Gao , Jiagui Liu , Tao Wu , Xiguang Gao , Yingdong Song","doi":"10.1016/j.jeurceramsoc.2024.117164","DOIUrl":"10.1016/j.jeurceramsoc.2024.117164","url":null,"abstract":"<div><div>Dynamic tensile experiments of unidirectional (UD) SiC<span><math><msub><mrow></mrow><mrow><mi>f</mi></mrow></msub></math></span>/PyC/SiC composites and SiC fiber bundles were performed using a Kolsky tension bar test system. Typical failure characteristics of UD ceramic matrix composites (CMCs), including matrix crack spacing, fiber pull-outs, matrix fracture surfaces and fiber fracture surfaces, were observed through optical and scanning electron microscopes. By combining micro-damage characteristics with mechanical behavior, we analyzed the dynamic damage mechanisms of UD-CMCs. Based on the test results, the dynamic loading effects on micro-mechanical parameters and their subsequent impact on the macro composite were determined. Finally, with these validated micro-parameters, we developed a rate-dependent constitutive model for UD-CMCs.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 6","pages":"Article 117164"},"PeriodicalIF":5.8,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143156917","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}
In this paper, the compressive properties of 3D needled Carbon/Carbon composites at high temperatures up to 2800 °C were revealed from the perspective of damage evolution and fracture behavior. At ambient temperature, the results of loading-unloading and in-situ X-ray computed tomography experiments show that cracks originate from the needle-punched region on the surface when the strain threshold exceeds 0.3 %. With further loading, the material exhibits nonlinear and cumulative damage characteristics. At ultra-high temperature, the compressive strength increases first and then decreases with the increase of temperature, and reaches the maximum at 1800 °C. Meanwhile, the fracture mechanism of temperature control is divided into two categories. Below 2400 °C, the bonding of the interface improves with the increase of temperature, and the shear bands and delamination lead to catastrophic failure. At higher temperatures, the material exhibits plastic buckling, accompanied by fiber breakage, fiber kink bands, transverse cracks and delamination.
{"title":"Damage evolution and failure behavior of 3D needled Carbon/Carbon composites under compressive at ultra-high temperatures up to 2800 °C","authors":"Kunjie Wang, Chenghai Xu, Bo Gao, Xinliang Zhao, Boyi Wang, Songhe Meng","doi":"10.1016/j.jeurceramsoc.2025.117183","DOIUrl":"10.1016/j.jeurceramsoc.2025.117183","url":null,"abstract":"<div><div>In this paper, the compressive properties of 3D needled Carbon/Carbon composites at high temperatures up to 2800 °C were revealed from the perspective of damage evolution and fracture behavior. At ambient temperature, the results of loading-unloading and in-situ X-ray computed tomography experiments show that cracks originate from the needle-punched region on the surface when the strain threshold exceeds 0.3 %. With further loading, the material exhibits nonlinear and cumulative damage characteristics. At ultra-high temperature, the compressive strength increases first and then decreases with the increase of temperature, and reaches the maximum at 1800 °C. Meanwhile, the fracture mechanism of temperature control is divided into two categories. Below 2400 °C, the bonding of the interface improves with the increase of temperature, and the shear bands and delamination lead to catastrophic failure. At higher temperatures, the material exhibits plastic buckling, accompanied by fiber breakage, fiber kink bands, transverse cracks and delamination.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 6","pages":"Article 117183"},"PeriodicalIF":5.8,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143156186","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 : 2025-01-03DOI: 10.1016/j.jeurceramsoc.2025.117181
Degang Li, Bo Zhang, Lixia Zhang, Qing Chang, Zhan Sun
To meet the demands of the advanced infrared windows with excellent optical and mechanical properties, Y2O3-MgO nanocomposite ceramic and TC4 alloy were brazed by using Ag-Cu-Ti filler. The microstructure and mechanical properties were studied in detail. The typical microstructure of the brazed joint is Y2O3-MgO/Cu2Y2O5 + Cu3Ti3O/TiCu + Ti2Cu + Ag(s,s)/Ti(s,s) + Ti2Cu/TC4. Our results indicate that Ti preferentially reacts with Y2O3-MgO at the initial stage. Subsequently, Cu participates in the interfacial reactions, leading to the formation of a reaction layer composed of Cu2Y2O5 and Cu3Ti3O. Maximum shear strength of 38 ± 7 MPa was achieved when the joint was brazed at 880 °C for 10 min. The Cu2Y2O5 + Cu3Ti3O interfacial reaction layer possesses higher hardness and modulus than the main products of the brazed joint, which is the primary weakness of the brazed joint.
{"title":"Interfacial microstructure and mechanical properties of Y2O3-MgO nanocomposite ceramic and Ti6Al4V joint brazed with AgCuTi filler","authors":"Degang Li, Bo Zhang, Lixia Zhang, Qing Chang, Zhan Sun","doi":"10.1016/j.jeurceramsoc.2025.117181","DOIUrl":"10.1016/j.jeurceramsoc.2025.117181","url":null,"abstract":"<div><div>To meet the demands of the advanced infrared windows with excellent optical and mechanical properties, Y<sub>2</sub>O<sub>3</sub>-MgO nanocomposite ceramic and TC4 alloy were brazed by using Ag-Cu-Ti filler. The microstructure and mechanical properties were studied in detail. The typical microstructure of the brazed joint is Y<sub>2</sub>O<sub>3</sub>-MgO/Cu<sub>2</sub>Y<sub>2</sub>O<sub>5</sub> + Cu<sub>3</sub>Ti<sub>3</sub>O/TiCu + Ti<sub>2</sub>Cu + Ag(s,s)/Ti(s,s) + Ti<sub>2</sub>Cu/TC4. Our results indicate that Ti preferentially reacts with Y<sub>2</sub>O<sub>3</sub>-MgO at the initial stage. Subsequently, Cu participates in the interfacial reactions, leading to the formation of a reaction layer composed of Cu<sub>2</sub>Y<sub>2</sub>O<sub>5</sub> and Cu<sub>3</sub>Ti<sub>3</sub>O. Maximum shear strength of 38 ± 7 MPa was achieved when the joint was brazed at 880 °C for 10 min. The Cu<sub>2</sub>Y<sub>2</sub>O<sub>5</sub> + Cu<sub>3</sub>Ti<sub>3</sub>O interfacial reaction layer possesses higher hardness and modulus than the main products of the brazed joint, which is the primary weakness of the brazed joint.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 6","pages":"Article 117181"},"PeriodicalIF":5.8,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143100848","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 : 2024-12-31DOI: 10.1016/j.jeurceramsoc.2024.117180
Wenxia Zhu, Xiaohui Xia, Yukun Zheng, Huiming Ji, Dong Su
Precursor derived SiBCN ceramic is considered as promising materials for advanced electromagnetic interference (EMI) shielding. Here, the graphene nanosheet (GNS) aerogel via high-temperature graphitization was used as conductive network for constructing GNS/SiBCN nanocomposites through polyborosilazane (PBSZ) precursor infiltration and pyrolysis. The graphitization process of GNS aerogels increases the electrical conductivity of GNS/SiBCN nanocomposites from 105 to 1168 S·m−1, and achieves an improved EMI shielding effectiveness (SETotal) from 24.1 to 39.3 dB. The SiBCN protection endows the nanocomposite with good oxidation resistance at 800 °C in air and high-temperature stability at 1400 °C in Ar. Moreover, the porous GNS/SiBCN nanocomposite with density of 0.11 g·cm−3 was attained by adjusting the PBSZ content of 10 % during the infiltration, further exhibiting a high SETotal of 32.7 dB and a high specific SETotal of 297 dB·g−1·cm3. Therefore, it’s an ideal route to develop lightweight EMI shielding materials used in high-temperature environment.
{"title":"Tailoring of carbon structure in lightweight GNS/SiBCN nanocomposites for enhanced electromagnetic interference shielding performance","authors":"Wenxia Zhu, Xiaohui Xia, Yukun Zheng, Huiming Ji, Dong Su","doi":"10.1016/j.jeurceramsoc.2024.117180","DOIUrl":"10.1016/j.jeurceramsoc.2024.117180","url":null,"abstract":"<div><div>Precursor derived SiBCN ceramic is considered as promising materials for advanced electromagnetic interference (EMI) shielding. Here, the graphene nanosheet (GNS) aerogel via high-temperature graphitization was used as conductive network for constructing GNS/SiBCN nanocomposites through polyborosilazane (PBSZ) precursor infiltration and pyrolysis. The graphitization process of GNS aerogels increases the electrical conductivity of GNS/SiBCN nanocomposites from 105 to 1168 S·m<sup>−1</sup>, and achieves an improved EMI shielding effectiveness (SE<sub>Total</sub>) from 24.1 to 39.3 dB. The SiBCN protection endows the nanocomposite with good oxidation resistance at 800 °C in air and high-temperature stability at 1400 °C in Ar. Moreover, the porous GNS/SiBCN nanocomposite with density of 0.11 g·cm<sup>−3</sup> was attained by adjusting the PBSZ content of 10 % during the infiltration, further exhibiting a high SE<sub>Total</sub> of 32.7 dB and a high specific SE<sub>Total</sub> of 297 dB·g<sup>−1</sup>·cm<sup>3</sup>. Therefore, it’s an ideal route to develop lightweight EMI shielding materials used in high-temperature environment.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 6","pages":"Article 117180"},"PeriodicalIF":5.8,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143156916","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 : 2024-12-31DOI: 10.1016/j.jeurceramsoc.2024.117178
Zhiyuan Hu , Chuanbing Cheng , Heng Cui , Mengqian Liu , Xinle Wang , Yuanhui Liu , Chenxu Li , Yibo Li , Yujun Zhao , Zhihao Wang , Runhua Fan
The emergence of high-entropy ceramics has provided a new effective strategy for adjusting the electrical properties of ceramics. Herein, high-entropy (Ti0.25Zr0.25Nb0.25Ta0.25)C ceramics were successfully prepared by the hot-pressure sintering at different sintering temperatures, and the effect of sintering temperature on their composition, conductivity and dielectric properties was investigated. The conductivity of the ceramics showed a decreasing trend with increasing sintering temperature. The ceramics displayed negative permittivity, which arisen from the low-frequency plasma state of free electrons in ceramics. The values of negative permittivity became larger with increasing sintering temperature, which was well analyzed by the Drude model. As the sintering temperature raised, the enhanced lattice distortion could inhibit the movement of free electrons, thereby leading to the reduced conductivity and increased negative permittivity. This study for the first time reported tunable negative permittivity behavior in high entropy ceramics, which is helpful to expand the research scope of high entropy ceramics.
{"title":"Adjustable negative permittivity behavior of high entropy (Ti0.25Zr0.25Nb0.25Ta0.25)C ceramics with different sintering temperatures","authors":"Zhiyuan Hu , Chuanbing Cheng , Heng Cui , Mengqian Liu , Xinle Wang , Yuanhui Liu , Chenxu Li , Yibo Li , Yujun Zhao , Zhihao Wang , Runhua Fan","doi":"10.1016/j.jeurceramsoc.2024.117178","DOIUrl":"10.1016/j.jeurceramsoc.2024.117178","url":null,"abstract":"<div><div>The emergence of high-entropy ceramics has provided a new effective strategy for adjusting the electrical properties of ceramics. Herein, high-entropy (Ti<sub>0.25</sub>Zr<sub>0.25</sub>Nb<sub>0.25</sub>Ta<sub>0.25</sub>)C ceramics were successfully prepared by the hot-pressure sintering at different sintering temperatures, and the effect of sintering temperature on their composition, conductivity and dielectric properties was investigated. The conductivity of the ceramics showed a decreasing trend with increasing sintering temperature. The ceramics displayed negative permittivity, which arisen from the low-frequency plasma state of free electrons in ceramics. The values of negative permittivity became larger with increasing sintering temperature, which was well analyzed by the Drude model. As the sintering temperature raised, the enhanced lattice distortion could inhibit the movement of free electrons, thereby leading to the reduced conductivity and increased negative permittivity. This study for the first time reported tunable negative permittivity behavior in high entropy ceramics, which is helpful to expand the research scope of high entropy ceramics.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 6","pages":"Article 117178"},"PeriodicalIF":5.8,"publicationDate":"2024-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143156583","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 : 2024-12-30DOI: 10.1016/j.jeurceramsoc.2024.117176
Zhufeng Liu , Zhaoqing Li , Qi Li , Changshun Wang , Peng Chen , Lei Yang , Lichao Zhang , Bin Su , Chunze Yan , Yusheng Shi
Additive manufacturing (AM) technology provides a pathway for the preparation of complex structured silicon carbide (SiC) ceramics. Due to the high brittleness of SiC materials and a high scrap rate for large and complex SiC ceramics, short-cut and continuous carbon fibers have been used to improve the toughness of AM SiC ceramics, but the reinforcement effect is limited. Here, we report a novel combination process of the continuous fiber AM, precursor infiltration pyrolysis (PIP) and liquid-phase silicon infiltration (LSI) to prepare continuous SiC fiber (SiCf) -reinforced SiC ceramic matrix composites (CMC). Continuous SiC fibers as reinforcing phases can improve the strength and toughness of SiC ceramics. The two polycarbosilane (PCS) PIP processes form a SiC interface layer on the surface of continuous fibers to avoid fiber corrosion during the LSI process. The multiple phenolic resin infiltration and pyrolysis processes regulate the carbon density and microstructure of carbonized parts. In the LSI process, the liquid-phase silicon reacts with partially pyrolytic carbon to generate SiC. When the carbon density of the carbonized part is 0.85 g/cm3, the final part has the high flexural strength and fracture toughness of 398 MPa and 10.79 MPa·m1/2, respectively. Through enhancing the strength and toughness of SiC ceramics, the complex SiC CMC parts prepared by the proposed combination process show great application prospects in various fields.
{"title":"Ultra-High strength and toughness continuous SiCf/SiC ceramic matrix composites prepared by an additive manufacturing manipulator","authors":"Zhufeng Liu , Zhaoqing Li , Qi Li , Changshun Wang , Peng Chen , Lei Yang , Lichao Zhang , Bin Su , Chunze Yan , Yusheng Shi","doi":"10.1016/j.jeurceramsoc.2024.117176","DOIUrl":"10.1016/j.jeurceramsoc.2024.117176","url":null,"abstract":"<div><div>Additive manufacturing (AM) technology provides a pathway for the preparation of complex structured silicon carbide (SiC) ceramics. Due to the high brittleness of SiC materials and a high scrap rate for large and complex SiC ceramics, short-cut and continuous carbon fibers have been used to improve the toughness of AM SiC ceramics, but the reinforcement effect is limited. Here, we report a novel combination process of the continuous fiber AM, precursor infiltration pyrolysis (PIP) and liquid-phase silicon infiltration (LSI) to prepare continuous SiC fiber (SiC<sub>f</sub>) -reinforced SiC ceramic matrix composites (CMC). Continuous SiC fibers as reinforcing phases can improve the strength and toughness of SiC ceramics. The two polycarbosilane (PCS) PIP processes form a SiC interface layer on the surface of continuous fibers to avoid fiber corrosion during the LSI process. The multiple phenolic resin infiltration and pyrolysis processes regulate the carbon density and microstructure of carbonized parts. In the LSI process, the liquid-phase silicon reacts with partially pyrolytic carbon to generate SiC. When the carbon density of the carbonized part is 0.85 g/cm<sup>3</sup>, the final part has the high flexural strength and fracture toughness of 398 MPa and 10.79 MPa·m<sup>1/2</sup>, respectively. Through enhancing the strength and toughness of SiC ceramics, the complex SiC CMC parts prepared by the proposed combination process show great application prospects in various fields.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 6","pages":"Article 117176"},"PeriodicalIF":5.8,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143156934","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 : 2024-12-30DOI: 10.1016/j.jeurceramsoc.2024.117177
Zofia Kucia , Maciej Bik , Piotr Jeleń , Zbigniew Olejniczak , Krzysztof Mroczka , Daria Pakuła , Robert Przekop , Martina Urbanova , Jiri Brus , Günter Motz , Maciej Sitarz
Polymer-derived silicon carbonitride SiCN(O) materials with tunable carbon content were obtained from polysilazanes synthesized from silazane monomers, and carbon-containing crosslinkers via the hydrosilylation reaction. The polysilazanes were characterized by ATR-FTIR and Raman spectroscopy in terms of the presence of various functional groups. Three polysilazanes were chosen as preceramic precursors for the materials, and pyrolyzed at 800°C in argon. DRIFT spectroscopy and 29Si MAS NMR confirmed the presence of Si–N bonds in the materials, and Si–C bonds in one sample only, as well as oxygen contamination in the form of Si–O bonds in all samples. Consequently, the obtained materials should be referred to as SiCN(O). Raman spectroscopy and 13C MAS NMR indicate that the materials contain the free carbon phase. Elemental analysis revealed that the carbon content in SiCN(O) materials can be adjusted from 25.7 at% to 45.3 at% by selecting appropriate silazane monomers and crosslinkers.
{"title":"Tuning the carbon content of silicon carbonitride SiCN(O) materials obtained from hydrosilylation-derived polysilazanes","authors":"Zofia Kucia , Maciej Bik , Piotr Jeleń , Zbigniew Olejniczak , Krzysztof Mroczka , Daria Pakuła , Robert Przekop , Martina Urbanova , Jiri Brus , Günter Motz , Maciej Sitarz","doi":"10.1016/j.jeurceramsoc.2024.117177","DOIUrl":"10.1016/j.jeurceramsoc.2024.117177","url":null,"abstract":"<div><div>Polymer-derived silicon carbonitride SiCN(O) materials with tunable carbon content were obtained from polysilazanes synthesized from silazane monomers, and carbon-containing crosslinkers via the hydrosilylation reaction. The polysilazanes were characterized by ATR-FTIR and Raman spectroscopy in terms of the presence of various functional groups. Three polysilazanes were chosen as preceramic precursors for the materials, and pyrolyzed at 800°C in argon. DRIFT spectroscopy and <sup>29</sup>Si MAS NMR confirmed the presence of Si–N bonds in the materials, and Si–C bonds in one sample only, as well as oxygen contamination in the form of Si–O bonds in all samples. Consequently, the obtained materials should be referred to as SiCN(O). Raman spectroscopy and <sup>13</sup>C MAS NMR indicate that the materials contain the free carbon phase. Elemental analysis revealed that the carbon content in SiCN(O) materials can be adjusted from 25.7 at% to 45.3 at% by selecting appropriate silazane monomers and crosslinkers.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 6","pages":"Article 117177"},"PeriodicalIF":5.8,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143156936","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 : 2024-12-29DOI: 10.1016/j.jeurceramsoc.2024.117175
Jingtong Li , Jian Zhang , Yulei Zhang , Yanqin Fu , Ruicong Chen , Haohui Zhang
A combustion fluid-structure coupling model of O2-C2H2 was established, and finite element simulation was employed to analyze the evolution law and interaction mechanism of HfC coating defects following oxygen acetylene ablation in this work. By conducting semi-quantitative simulations of the combustion reaction and flame erosion flow field, the distribution of various products in ablative flames on the surface of coated samples was obtained, thereby revealing the transition pattern of flame flow from vertical to horizontal direction. The results showed that the ablation morphology in different regions of HfC coated samples was determined by temperature, oxidation degree, and flame flow erosion behavior, which was consistent with the surface and cross-section images of the specimen after ablation. Moreover, vertically oriented cracks continued to propagate along their original surface and evolved into penetrating cracks, while inclined cracks tended to develop into inclined cracks or stepped cracks, which was supported by experimental results. Furthermore, the micropores had a promoting influence on crack growth, and there was a competitive effect among the pores of different positions and sizes in attracting cracks. This study provides theoretical guidance for further analyzing ablation defects and offers fundamental insights for improving the ablation resistance of coating.
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