Pub Date : 2026-02-04DOI: 10.1016/j.jeurceramsoc.2026.118212
Xinyu Wang , Ruipeng Wang , Jianli Jiang , Haining Meng , Haigang Hou , Jian Yang , Guiwu Liu , Guanjun Qiao
PbTe-based thermoelectric materials are promising for mid-temperature waste heat recovery, yet n-type PbTe underperforms its p-type counterpart. Herein, high-performance n-type PbTe is achieved through I/Ge co-doping and in-situ composite engineering with Sb2Te3 prepared by melting combined spark plasma sintering. Sb2Te3 alloying introduce in-situ formed Sb/Sb2Te3 precipitates. Furthermore, iodine doping optimizes the carrier concentration to ∼3.4 × 1019 cm–3, boosting the room-temperature electrical conductivity to ∼1404 S cm−1 and yielding a high power factor of ∼17.4 μW cm−1 K−2 for the PbTe-Sb2Te3 sample. Meanwhile, lattice thermal conductivity is synergistically suppressed to ∼0.37 W m–1 K–1 at 673 K through Ge-induced point defects/off-center anharmonicity and Sb/Sb2Te3 precipitates. This synergistic strategy results in a peak ZT of ∼1.30 at 823 K and a high average ZT of ∼0.91 at 323–823 K. This work demonstrates that synergistic I/Ge co-doping and composite precipitation effectively enhance thermoelectric performance in n-type PbTe.
基于PbTe的热电材料有望用于中温废热回收，但n型PbTe的性能不如p型。本文通过I/Ge共掺杂和原位复合工程，以熔融组合火花等离子烧结法制备Sb2Te3，实现了高性能n型PbTe。Sb2Te3合金引入原位形成的Sb/Sb2Te3相。此外，碘掺杂将载流子浓度优化到~ 3.4 × 1019 cm - 3，将PbTe-Sb2Te3样品的室温电导率提高到~ 1404 S cm - 1，并产生了~ 17.4 μW cm - 1 K - 2的高功率因数。同时，通过锗诱导的点缺陷/偏心不谐性和Sb/Sb2Te3析出，晶格热导率协同抑制到~ 0.37 W m-1 K - 1（673 K）。这种协同策略导致在823 K处ZT峰值为~ 1.30，在323-823 K处ZT峰值为~ 0.91。本工作证明了协同I/Ge共掺杂和复合沉淀有效地提高了n型PbTe的热电性能。
{"title":"Synergistic enhancement of thermoelectric performance in n-type Sb2Te3 alloyed PbTe via I/Ge co-doping","authors":"Xinyu Wang , Ruipeng Wang , Jianli Jiang , Haining Meng , Haigang Hou , Jian Yang , Guiwu Liu , Guanjun Qiao","doi":"10.1016/j.jeurceramsoc.2026.118212","DOIUrl":"10.1016/j.jeurceramsoc.2026.118212","url":null,"abstract":"<div><div>PbTe-based thermoelectric materials are promising for mid-temperature waste heat recovery, yet n-type PbTe underperforms its p-type counterpart. Herein, high-performance n-type PbTe is achieved through I/Ge co-doping and in-situ composite engineering with Sb<sub>2</sub>Te<sub>3</sub> prepared by melting combined spark plasma sintering. Sb<sub>2</sub>Te<sub>3</sub> alloying introduce in-situ formed Sb/Sb<sub>2</sub>Te<sub>3</sub> precipitates. Furthermore, iodine doping optimizes the carrier concentration to ∼3.4 × 10<sup>19</sup> cm<sup>–3</sup>, boosting the room-temperature electrical conductivity to ∼1404 S cm<sup>−1</sup> and yielding a high power factor of ∼17.4 μW cm<sup>−1</sup> K<sup>−2</sup> for the PbTe-Sb<sub>2</sub>Te<sub>3</sub> sample. Meanwhile, lattice thermal conductivity is synergistically suppressed to ∼0.37 W m<sup>–1</sup> K<sup>–1</sup> at 673 K through Ge-induced point defects/off-center anharmonicity and Sb/Sb<sub>2</sub>Te<sub>3</sub> precipitates. This synergistic strategy results in a peak ZT of ∼1.30 at 823 K and a high average ZT of ∼0.91 at 323–823 K. This work demonstrates that synergistic I/Ge co-doping and composite precipitation effectively enhance thermoelectric performance in n-type PbTe.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 9","pages":"Article 118212"},"PeriodicalIF":6.2,"publicationDate":"2026-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146191688","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 : 2026-02-03DOI: 10.1016/j.jeurceramsoc.2026.118207
Min-Soo Nam , Jin-Kwon Kim , Sahn Nahm , Seongwon Kim
Integrated Gasification Combined Cycle (IGCC) technology offers efficient and cleaner coal-based power generation but introduces corrosion challenges associated with high temperatures and molten slag. This study examines the corrosion behavior of ytterbium monosilicate (Yb₂SiO₅) and its composites containing 5 and 10 wt% Al₂O₃ under IGCC slag conditions. The addition of Al₂O₃ promotes the formation of garnet phases with higher thermal expansion, improving compatibility with the substrate. Samples exposed to molten slag were evaluated for microstructural evolution, thermal expansion, conductivity, and slag resistance. Yb₂SiO₅ exhibited high thermal stability and formed dense protective layers that limited slag infiltration. The composites enhanced thermal compatibility with carbon steel, increasing the coefficient of thermal expansion (CTE) to 9.8 × 10⁻⁶ and 10.9 × 10⁻⁶ K⁻¹ , respectively. The formation of a protective Yb₂Si₂O₇ layer underscores the potential of ytterbium silicates as effective high-temperature coatings for IGCC applications.
{"title":"Corrosion resistance of Yb-silicate materials to molten slag for protective coating applications","authors":"Min-Soo Nam , Jin-Kwon Kim , Sahn Nahm , Seongwon Kim","doi":"10.1016/j.jeurceramsoc.2026.118207","DOIUrl":"10.1016/j.jeurceramsoc.2026.118207","url":null,"abstract":"<div><div>Integrated Gasification Combined Cycle (IGCC) technology offers efficient and cleaner coal-based power generation but introduces corrosion challenges associated with high temperatures and molten slag. This study examines the corrosion behavior of ytterbium monosilicate (Yb₂SiO₅) and its composites containing 5 and 10 wt% Al₂O₃ under IGCC slag conditions. The addition of Al₂O₃ promotes the formation of garnet phases with higher thermal expansion, improving compatibility with the substrate. Samples exposed to molten slag were evaluated for microstructural evolution, thermal expansion, conductivity, and slag resistance. Yb₂SiO₅ exhibited high thermal stability and formed dense protective layers that limited slag infiltration. The composites enhanced thermal compatibility with carbon steel, increasing the coefficient of thermal expansion (CTE) to 9.8 × 10⁻⁶ and 10.9 × 10⁻⁶ K⁻¹ , respectively. The formation of a protective Yb₂Si₂O₇ layer underscores the potential of ytterbium silicates as effective high-temperature coatings for IGCC applications.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 9","pages":"Article 118207"},"PeriodicalIF":6.2,"publicationDate":"2026-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146191681","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 : 2026-02-02DOI: 10.1016/j.jeurceramsoc.2026.118204
Siyuan Wang , Wei Cai , WenJin Wu , Huasong Liu , Jianwei Zheng , Liang Qiao , Yao Ying , Juan Li , Jing Yu , Naoki Wakiya , Jingwu Zheng , Shenglei Che
Cold sintering, characterized by low temperature, low energy consumption, and environmental friendliness, offers a promising route for sintering SrFe12O19. This study systematically investigates the effects of transient solvent composition, sintering temperature, and powder morphology on the densification mechanism of SrFe12O19. In the acetic acid–ethanol transient solvent system, Fe3 + ions preferentially dissolved and reacted with acetate and hydroxyl groups to form iron–carboxylate species, which facilitated particle bonding and densification. However, increased solvent concentration and cold sintering temperature cause its decomposition into Fe2O3, and gas release; trapped gas forms pores that impede densification, leading to reduced densification at higher temperatures. Meanwhile, irregular powders promote the “dissolution–precipitation” process more effectively than spherical ones. Under optimized conditions, 16 mol/L transient solvent concentration, 40 wt% addition, 250 °C sintering temperature, 1 GPa pressure, and 3 h holding time, the ball-milled powder achieved a optimal combined magnetic properties (Hcj = 5.31 kOe, Ms = 60.39 emu/g).
{"title":"Mechanistic elucidation of cold sintering behavior in SrFe12O19 ceramics: Role of transient solvent, temperature, and particle morphology","authors":"Siyuan Wang , Wei Cai , WenJin Wu , Huasong Liu , Jianwei Zheng , Liang Qiao , Yao Ying , Juan Li , Jing Yu , Naoki Wakiya , Jingwu Zheng , Shenglei Che","doi":"10.1016/j.jeurceramsoc.2026.118204","DOIUrl":"10.1016/j.jeurceramsoc.2026.118204","url":null,"abstract":"<div><div>Cold sintering, characterized by low temperature, low energy consumption, and environmental friendliness, offers a promising route for sintering SrFe<sub>12</sub>O<sub>19</sub>. This study systematically investigates the effects of transient solvent composition, sintering temperature, and powder morphology on the densification mechanism of SrFe<sub>12</sub>O<sub>19</sub>. In the acetic acid–ethanol transient solvent system, Fe<sup>3 +</sup> ions preferentially dissolved and reacted with acetate and hydroxyl groups to form iron–carboxylate species, which facilitated particle bonding and densification. However, increased solvent concentration and cold sintering temperature cause its decomposition into Fe<sub>2</sub>O<sub>3</sub>, and gas release; trapped gas forms pores that impede densification, leading to reduced densification at higher temperatures. Meanwhile, irregular powders promote the “dissolution–precipitation” process more effectively than spherical ones. Under optimized conditions, 16 mol/L transient solvent concentration, 40 wt% addition, 250 °C sintering temperature, 1 GPa pressure, and 3 h holding time, the ball-milled powder achieved a optimal combined magnetic properties (<em>H</em><sub><em>cj</em></sub> = 5.31 kOe, <em>M</em><sub><em>s</em></sub> = 60.39 emu/g).</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 9","pages":"Article 118204"},"PeriodicalIF":6.2,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098721","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 : 2026-02-02DOI: 10.1016/j.jeurceramsoc.2026.118206
F. Monteverde , S. Cassese , D. De Prisco , S. Mungiguerra , R. Savino
Compositionally complex (CC) AlB2-type diboride solid solutions (DSSs) containing IV-V-VI group metals were investigated as candidate materials for hypersonic applications using a ground entry simulator. Each CCDSS was composed of Ti and three other transition metals among Zr-Hf-Nb-Ta. Single phase CCDSS dense discs were spark plasma sintered and then exposed to a supersonic dissociated airflow (nominal Mach 3). The overall degradation of the discs was highly dependent on the combination of starting metals, and massive preferential oxidation occurred. The coexistence of Nb and Ta was detrimental. A thermal study was devised and implemented in a numerical model to validate the experimental set-up. The experimental results also showed good agreement with predictions based on a thermodynamic assessment.
{"title":"Searching the limits of compositionally complex AlB2-type diboride solid solutions for hypersonic applications","authors":"F. Monteverde , S. Cassese , D. De Prisco , S. Mungiguerra , R. Savino","doi":"10.1016/j.jeurceramsoc.2026.118206","DOIUrl":"10.1016/j.jeurceramsoc.2026.118206","url":null,"abstract":"<div><div>Compositionally complex (CC) AlB<sub>2</sub>-type diboride solid solutions (DSSs) containing IV-V-VI group metals were investigated as candidate materials for hypersonic applications using a ground entry simulator. Each CCDSS was composed of Ti and three other transition metals among Zr-Hf-Nb-Ta. Single phase CCDSS dense discs were spark plasma sintered and then exposed to a supersonic dissociated airflow (nominal Mach 3). The overall degradation of the discs was highly dependent on the combination of starting metals, and massive preferential oxidation occurred. The coexistence of Nb and Ta was detrimental. A thermal study was devised and implemented in a numerical model to validate the experimental set-up. The experimental results also showed good agreement with predictions based on a thermodynamic assessment.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 9","pages":"Article 118206"},"PeriodicalIF":6.2,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146191593","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 : 2026-02-02DOI: 10.1016/j.jeurceramsoc.2026.118205
Yang Zhou , Yanling Huang , Qiumei Huang , Ning Guan , Ning Zhang , Huaicheng Xiang , Ying Tang , Liang Fang
Next-generation wireless communication demands microwave dielectric ceramics that effectively achieve ultra-low loss, a stable resonant frequency, and a low permittivity. Here we demonstrate an entropy-engineering strategy that selectively disorders the [A(2)O6] octahedral site while preserving the rigid [GaO4] tetrahedral backbone in gallium-based olivine A2GaO4. A series of CaY1–x(Nd0.25Sm0.25Eu0.25Yb0.25)xGaO4 ceramics was synthesized by solid-state reaction at 1260–1420 °C. Systematic increases in configurational entropy (ΔSconfig) and ionic-size disorder (δR) drive a reversible Pnma → Pmnb symmetry switch, suppress phase separation, and expand the lattice. At x = 0.8, the high-entropy single-phase olivine exhibits εr = 9.2 ± 0.2, Q×f = 151,025 ± 400 GHz, and τf = -39.8 ± 2.0 ppm/°C, while Vickers hardness rises to 5.79 ± 0.2 GPa. Ultra-low loss is synergistically influenced by ΔSconfig, δR, and packing fraction. A C-band dielectric resonator antenna fabricated from the x = 0.8 composition achieves 92.63 % radiation efficiency and 6.39 dBi gain, validating the entropy-design paradigm for high-frequency applications.
{"title":"Entropy-driven design of ultra-low loss olivine CaY1–x(Nd0.25Sm0.25Eu0.25Yb0.25)xGaO4 microwave dielectric ceramics for 5 G dielectric resonator antennas","authors":"Yang Zhou , Yanling Huang , Qiumei Huang , Ning Guan , Ning Zhang , Huaicheng Xiang , Ying Tang , Liang Fang","doi":"10.1016/j.jeurceramsoc.2026.118205","DOIUrl":"10.1016/j.jeurceramsoc.2026.118205","url":null,"abstract":"<div><div>Next-generation wireless communication demands microwave dielectric ceramics that effectively achieve ultra-low loss, a stable resonant frequency, and a low permittivity. Here we demonstrate an entropy-engineering strategy that selectively disorders the [A(2)O<sub>6</sub>] octahedral site while preserving the rigid [GaO<sub>4</sub>] tetrahedral backbone in gallium-based olivine A<sub>2</sub>GaO<sub>4</sub>. A series of CaY<sub>1–<em>x</em></sub>(Nd<sub>0.25</sub>Sm<sub>0.25</sub>Eu<sub>0.25</sub>Yb<sub>0.25</sub>)<sub><em>x</em></sub>GaO<sub>4</sub> ceramics was synthesized by solid-state reaction at 1260–1420 °C. Systematic increases in configurational entropy (ΔS<sub>config</sub>) and ionic-size disorder (<em>δ</em><sub>R</sub>) drive a reversible <em>Pnma</em> → <em>Pmnb</em> symmetry switch, suppress phase separation, and expand the lattice. At <em>x</em> = 0.8, the high-entropy single-phase olivine exhibits <em>ε</em><sub><em>r</em></sub> = 9.2 ± 0.2, <em>Q×f</em> = 151,025 ± 400 GHz, and <em>τ</em><sub><em>f</em></sub> = -39.8 ± 2.0 ppm/°C, while Vickers hardness rises to 5.79 ± 0.2 GPa. Ultra-low loss is synergistically influenced by ΔS<sub>config</sub>, <em>δ</em><sub>R</sub>, and packing fraction. A C-band dielectric resonator antenna fabricated from the <em>x</em> = 0.8 composition achieves 92.63 % radiation efficiency and 6.39 dBi gain, validating the entropy-design paradigm for high-frequency applications.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 9","pages":"Article 118205"},"PeriodicalIF":6.2,"publicationDate":"2026-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098816","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 : 2026-01-31DOI: 10.1016/j.jeurceramsoc.2026.118203
Yueying Yin , Zemin Liu , Diansen Li , Lei Jiang , Stepan V. Lomov , Frederik Desplentere
This study systematically investigates the evolution of bending properties and damage mechanisms of three-dimensional angle-interlock woven alumina/mullite ceramic matrix composites (3DAW Al₂O₃-CMCs) under room-temperature (RT) and various high-temperature environments. The experimental temperature range was set from RT to 1200°C. The results indicate that the bending properties of 3DAW Al₂O₃-CMCs exhibit a non-monotonic temperature dependence, initially increasing before decreasing, with optimal performance observed at 1000°C where the maximum bending strength and bending modulus reach 128 MPa and 15.20 GPa, respectively. The damage mechanism shifts with increasing temperature: from localized fiber fracture and matrix cracking, to ductile fracture characterized by matrix softening and enhanced interfacial bonding, and finally to the state of matrix degradation coupled with fiber bundles collapse.
{"title":"Effect of temperature on bending mechanical behavior of 3D angle-interlock woven Al₂O₃/mullite ceramic matrix composites","authors":"Yueying Yin , Zemin Liu , Diansen Li , Lei Jiang , Stepan V. Lomov , Frederik Desplentere","doi":"10.1016/j.jeurceramsoc.2026.118203","DOIUrl":"10.1016/j.jeurceramsoc.2026.118203","url":null,"abstract":"<div><div>This study systematically investigates the evolution of bending properties and damage mechanisms of three-dimensional angle-interlock woven alumina/mullite ceramic matrix composites (3DAW Al₂O₃-CMCs) under room-temperature (RT) and various high-temperature environments. The experimental temperature range was set from RT to 1200°C. The results indicate that the bending properties of 3DAW Al₂O₃-CMCs exhibit a non-monotonic temperature dependence, initially increasing before decreasing, with optimal performance observed at 1000°C where the maximum bending strength and bending modulus reach 128 MPa and 15.20 GPa, respectively. The damage mechanism shifts with increasing temperature: from localized fiber fracture and matrix cracking, to ductile fracture characterized by matrix softening and enhanced interfacial bonding, and finally to the state of matrix degradation coupled with fiber bundles collapse.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 9","pages":"Article 118203"},"PeriodicalIF":6.2,"publicationDate":"2026-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146098817","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 : 2026-01-31DOI: 10.1016/j.jeurceramsoc.2026.118182
Min-Soo Nam , Sahn Nahm , Seongwon Kim
Environmental barrier coatings (EBCs) are essential for protecting SiCf/SiC ceramic matrix composites from water vapor recession and calcia-magnesia-aluminosilicate (CMAS) corrosion in gas turbines. In this study, (YbxSc1−x)2Si2O7 solid solutions with varying Yb/Sc ratios are evaluated as CMAS-resistant EBC topcoat candidates. Five compositions are synthesized and tested at 1500 °C. Corrosion resistance improves as the optical basicity of the disilicate matches that of CMAS, minimizing chemical reactions and apatite formation; Sc-containing compositions exhibit the best performance. Increasing Sc content decreases the ionic radius and lattice parameters, further inhibiting Ca2+ –to–RE3+ substitution. Microstructural analysis shows Yb-rich samples retain surface CMAS, whereas Sc-rich samples experience rapid grain-boundary infiltration with less reaction. Thermophysical measurements confirm low, stable thermal conductivity and coefficient of thermal expansion compatibility with SiCf/SiC substrates. These results indicate that (YbxSc1−x)2Si2O7 solid solutions offer a balanced combination of CMAS corrosion resistance, thermal compatibility, and low thermal conductivity for robust EBCs.
{"title":"Reaction-controlled effects of (YbxSc1-x)2Si2O7 solid solution against molten calcia-magnesia-aluminosilicate (CMAS) corrosion for environmental barrier coating application","authors":"Min-Soo Nam , Sahn Nahm , Seongwon Kim","doi":"10.1016/j.jeurceramsoc.2026.118182","DOIUrl":"10.1016/j.jeurceramsoc.2026.118182","url":null,"abstract":"<div><div>Environmental barrier coatings (EBCs) are essential for protecting SiC<sub>f</sub>/SiC ceramic matrix composites from water vapor recession and calcia-magnesia-aluminosilicate (CMAS) corrosion in gas turbines. In this study, (Yb<sub>x</sub>Sc<sub>1−x</sub>)<sub>2</sub>Si<sub>2</sub>O<sub>7</sub> solid solutions with varying Yb/Sc ratios are evaluated as CMAS-resistant EBC topcoat candidates. Five compositions are synthesized and tested at 1500 °C. Corrosion resistance improves as the optical basicity of the disilicate matches that of CMAS, minimizing chemical reactions and apatite formation; Sc-containing compositions exhibit the best performance. Increasing Sc content decreases the ionic radius and lattice parameters, further inhibiting Ca<sup>2</sup><sup>+</sup> –to–RE<sup>3+</sup> substitution. Microstructural analysis shows Yb-rich samples retain surface CMAS, whereas Sc-rich samples experience rapid grain-boundary infiltration with less reaction. Thermophysical measurements confirm low, stable thermal conductivity and coefficient of thermal expansion compatibility with SiC<sub>f</sub>/SiC substrates. These results indicate that (Yb<sub>x</sub>Sc<sub>1−x</sub>)<sub>2</sub>Si<sub>2</sub>O<sub>7</sub> solid solutions offer a balanced combination of CMAS corrosion resistance, thermal compatibility, and low thermal conductivity for robust EBCs.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 9","pages":"Article 118182"},"PeriodicalIF":6.2,"publicationDate":"2026-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146191682","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 : 2026-01-30DOI: 10.1016/j.jeurceramsoc.2026.118191
Yimin Ouyang , Saidi Wang , Linwei Guo , Tao Zhang , Mengdong Ma , Bin Du
Linking atomic-scale modeling with experimental processes, first-principles calculations were combined with polymer-derived ceramic (PDC) route and high-pressure sintering to design and fabricate (Ta0.25Nb0.25Hf0.25Zr0.25)C high-entropy carbides (HECs) with exceptional hardness and modulus. The calculations show that increasing applied pressure enhances the elastic constants, bulk modulus, and theoretical hardness, guiding powder densification at 6 GPa and 1600°C (HEC1) or 1800°C (HEC2). Dense bulk ceramics with relative densities of 95.19 % and 96.33 %, were obtained without phase decomposition. Compared with HEC1, HEC2 exhibits improved crystallinity, reduced porosity, and enhanced mechanical properties, including a Vickers hardness of 28.3 GPa, nanoindentation hardness of 33.2 GPa, elastic modulus of 440.7 GPa, and fracture toughness of 4.0 MPa·m1/2. These findings highlight that integrating the PDC route with high-pressure sintering facilitates the fabrication of dense, high-performance HECs, offering a promising pathway for structural applications in extreme environments.
{"title":"First-principles guided design and high-pressure sintering of polymer-derived high-entropy carbides with superior hardness and modulus","authors":"Yimin Ouyang , Saidi Wang , Linwei Guo , Tao Zhang , Mengdong Ma , Bin Du","doi":"10.1016/j.jeurceramsoc.2026.118191","DOIUrl":"10.1016/j.jeurceramsoc.2026.118191","url":null,"abstract":"<div><div>Linking atomic-scale modeling with experimental processes, first-principles calculations were combined with polymer-derived ceramic (PDC) route and high-pressure sintering to design and fabricate (Ta<sub>0.25</sub>Nb<sub>0.25</sub>Hf<sub>0.25</sub>Zr<sub>0.25</sub>)C high-entropy carbides (HECs) with exceptional hardness and modulus. The calculations show that increasing applied pressure enhances the elastic constants, bulk modulus, and theoretical hardness, guiding powder densification at 6 GPa and 1600°C (HEC1) or 1800°C (HEC2). Dense bulk ceramics with relative densities of 95.19 % and 96.33 %, were obtained without phase decomposition. Compared with HEC1, HEC2 exhibits improved crystallinity, reduced porosity, and enhanced mechanical properties, including a Vickers hardness of 28.3 GPa, nanoindentation hardness of 33.2 GPa, elastic modulus of 440.7 GPa, and fracture toughness of 4.0 MPa·m<sup>1/2</sup>. These findings highlight that integrating the PDC route with high-pressure sintering facilitates the fabrication of dense, high-performance HECs, offering a promising pathway for structural applications in extreme environments.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 8","pages":"Article 118191"},"PeriodicalIF":6.2,"publicationDate":"2026-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146080441","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 : 2026-01-29DOI: 10.1016/j.jeurceramsoc.2026.118190
P. Khamsepour , P. Bansal , D. Guay , A.C. Tavares , B. Guerreiro , R.S. Lima , K.R. Beyerlein
Ytterbium disilicate (YbDS) environmental barrier coatings (EBCs) are deposited by atmospheric plasma spray (APS) to protect aeroengine components made of SiCfiber(f)/SiC ceramic matrix composites. During deposition, rapid solidification of molten YbDS particles upon impact creates an amorphous structure which needs to be crystallized. This study optimized crystallization heat treatment for dense (∼2 % porosity) EBCs with as-sprayed crystallinity between 10 % and 50 %. Stable ytterbium silicate phases (YbDS and Yb₂SiO₅ (YbMS)) are formed above 1200 °C, regardless of initial crystallinity. EBCs with crystallinity of 15 % produced metastable phases at 1100 °C, requiring at least 10 h to transform them into stable phases, while coatings with 50 % crystallinity formed stable phase after only 4 h. The morphology and hardness of EBCs after crystallization are shown to be comparable irrespective of the heat treatment temperature. This demonstrates that partially crystalline as-sprayed YbDS can be crystallized faster and at lower temperatures, potentially reducing production costs.
{"title":"Reducing heat treatment time and temperature for dense crystalline ytterbium disilicate environmental barrier coatings","authors":"P. Khamsepour , P. Bansal , D. Guay , A.C. Tavares , B. Guerreiro , R.S. Lima , K.R. Beyerlein","doi":"10.1016/j.jeurceramsoc.2026.118190","DOIUrl":"10.1016/j.jeurceramsoc.2026.118190","url":null,"abstract":"<div><div>Ytterbium disilicate (YbDS) environmental barrier coatings (EBCs) are deposited by atmospheric plasma spray (APS) to protect aeroengine components made of SiC<sub>fiber(f)</sub>/SiC ceramic matrix composites. During deposition, rapid solidification of molten YbDS particles upon impact creates an amorphous structure which needs to be crystallized. This study optimized crystallization heat treatment for dense (∼2 % porosity) EBCs with as-sprayed crystallinity between 10 % and 50 %. Stable ytterbium silicate phases (YbDS and Yb₂SiO₅ (YbMS)) are formed above 1200 °C, regardless of initial crystallinity. EBCs with crystallinity of 15 % produced metastable phases at 1100 °C, requiring at least 10 h to transform them into stable phases, while coatings with 50 % crystallinity formed stable phase after only 4 h. The morphology and hardness of EBCs after crystallization are shown to be comparable irrespective of the heat treatment temperature. This demonstrates that partially crystalline as-sprayed YbDS can be crystallized faster and at lower temperatures, potentially reducing production costs.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 8","pages":"Article 118190"},"PeriodicalIF":6.2,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079967","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 : 2026-01-29DOI: 10.1016/j.jeurceramsoc.2026.118183
M. Sayed , N.A. Ajiba , S.B. Hanna, S.M. Naga
The present study aims to fabricate porous SiC/cordierite composites using the direct foaming technique followed by a sintering process, targeting enhanced thermal shock resistance and thermal expansion behavior. For this purpose, SiC was added in varying contents (20, 40, and 60 wt%) to the prepared pure stoichiometric cordierite matrix to evaluate their effects on porosity, phase composition, microstructure, mechanical, and thermal properties of the produced composites. The results showed that the porosity of the fabricated composites increased from 55.34 % to 68.49 % with the addition of SiC. The X-ray analysis (XRD) indicated that the addition of 20–40 wt% SiC induced a transformation from hexagonal to orthorhombic cordierite, whereas a higher SiC content of 60 wt% resulted in the coexistence of both α- and β-cordierite phases. The coefficient of thermal expansion (CTE) decreased with the addition of SiC into the cordierite matrix, while the compressive strength exhibited a maximum value for the 20 wt% SiC composite with a negative coefficient of thermal expansion. The SiC/cordierite composites demonstrated significantly improved thermal shock resistance compared to pure cordierite, allowing the SiC/cordierite composites to withstand over 40 thermal cycles without failure. The results suggest that the fabricated SiC/cordierite composites are promising candidates for high-temperature applications, offering a favorable combination of thermal stability, mechanical strength, and enhanced thermal shock resistance.
{"title":"Processing of porous SiC/cordierite composites with enhanced thermal shock resistance and negative thermal expansion","authors":"M. Sayed , N.A. Ajiba , S.B. Hanna, S.M. Naga","doi":"10.1016/j.jeurceramsoc.2026.118183","DOIUrl":"10.1016/j.jeurceramsoc.2026.118183","url":null,"abstract":"<div><div>The present study aims to fabricate porous SiC/cordierite composites using the direct foaming technique followed by a sintering process, targeting enhanced thermal shock resistance and thermal expansion behavior. For this purpose, SiC was added in varying contents (20, 40, and 60 wt%) to the prepared pure stoichiometric cordierite matrix to evaluate their effects on porosity, phase composition, microstructure, mechanical, and thermal properties of the produced composites. The results showed that the porosity of the fabricated composites increased from 55.34 % to 68.49 % with the addition of SiC. The X-ray analysis (XRD) indicated that the addition of 20–40 wt% SiC induced a transformation from hexagonal to orthorhombic cordierite, whereas a higher SiC content of 60 wt% resulted in the coexistence of both α- and β-cordierite phases. The coefficient of thermal expansion (CTE) decreased with the addition of SiC into the cordierite matrix, while the compressive strength exhibited a maximum value for the 20 wt% SiC composite with a negative coefficient of thermal expansion. The SiC/cordierite composites demonstrated significantly improved thermal shock resistance compared to pure cordierite, allowing the SiC/cordierite composites to withstand over 40 thermal cycles without failure. The results suggest that the fabricated SiC/cordierite composites are promising candidates for high-temperature applications, offering a favorable combination of thermal stability, mechanical strength, and enhanced thermal shock resistance.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"46 8","pages":"Article 118183"},"PeriodicalIF":6.2,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146079973","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号