CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Wei Fan,Yanfen Liu,Zebin Lv,Yu Bai,Yu Wang,Kun Liu,Zhiye Lin,Jianming Ou
The medium-entropy ceramic (La 1/3 Nd 1/3 Gd 1/3 ) 2 (Zr 3/4 Ce 1/4 ) 2 O 7 and high-entropy ceramic (La 1/5 Nd 1/5 Sm 1/5 Eu 1/5 Gd 1/5 ) 2 (Zr 3/4 Ce 1/4 ) 2 O 7 were successfully synthesized. The two ceramics had a pyrochlore-fluorite dual-phase structure, and they exhibited excellent phase stability at elevated temperature. Grain refinement or solution strengthening improved the Vickers hardness , fracture toughness and elastic modulus of the dual-phase ceramics. Compared with the single-element ceramic La 2 Zr 2 O 7 , multicomponent doping resulted in a significant increase in the thermal expansion coefficient. Simultaneously, the thermal conductivity of the dual-phase ceramics was lower than that of single-phase ones. In addition, on account of the large size disorder parameter of the medium-entropy ceramic, the thermal conductivity could outperform its high-entropy counterpart. These results indicate that pyrochlore-fluorite dual-phase rare-earth zirconates have enormous potential in applications concerning next generation thermal barrier coatings .
研究领域:
材料科学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2025
·
IF 14.3
Yanzhao Zhang,GuoXiang Zhou,Yuhang Zhang,Ning Xie,Lanlan Yang,Kunpeng Lin,Zhe Zhao,Meiling Yang,Huatay Lin,Zhihua Yang,Dechang Jia,Yu Zhou
Selective ion doping is a promising method to enhance the overall performance of perovskite dielectric ceramics. However, the confrontations among the dielectric constant ( ε r ), near-zero temperature coefficient of resonant frequency (TCF), and quality factor ( Q × f ) remain key challenges in high-performance dielectric ceramics. To leverage the trade-off conflicts, using dual-phase perovskite-based dielectric ceramic composites could be a potentially ideal solution. Unfortunately, the selected ions are hard to be doped into the perovskite phase due to the sintering temperature disparity of the two phases, thereby significantly impacting the modification effect. In this study, a “wedge” strategy was employed in a MgTiO 3 -CaTiO 3 dual-phase dielectric ceramic composite by using Ce as an auxiliary dopant to realize the main Hf doping in the CaTiO 3 phase due to the lattice distortion. This strategy also harmonizes the confrontation of the sintering temperature disparity between the two components of CaTiO 3 and MgTiO 3 . The Hf 4+ doping level of as high as 40 mol.% with a reduced sintering temperature of over 200 °C was successfully achieved by using this “wedge” strategy. Most importantly, the trade-off conflicts among the ε r , near-zero TCF, and Q × f have been considerably reduced and harmonized due to the successful introduction of a high dosage of Hf dopant in the CaTiO 3 phase without sacrificing the intact structure of MgTiO 3 . This strategy not only sheds light on manufacturing high-performance dual-phase dielectric ceramics with trade-off conflicts of properties but also provides an innovative pathway to address the challenge of mismatch of sintering temperature for selective ion doping in multiple-phase ceramic composites.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Ying Peng,Yongshuai Xie,Zhezhe Deng,Dehua Ma,Benxue Liu,Xinqiang Wang,Guanghui Zhang,Luyi Zhu
The inherent brittleness and hydrophilicity of ceramics pose a great challenge to designing a reliable structure that can resist mechanical loads and moisture in extreme conditions with high temperature and high humidity. Here, we report a two-phase hydrophobic silica–zirconia composite ceramic nanofiber membrane (H-ZSNFM) with exceptional mechanical robustness and high-temperature hydrophobic resistance. For the dual-phasic nanofibers, the amorphous silica blocked the connection of zirconia nanocrystals, and the lattice distortion was observed due to Si in the ZrO2 lattice. H-ZSNFM has strong strength (5–8.4 MPa), high hydrophobic temperature resistance (450 °C), high porosity (89%), low density (40 mg/cm3), low thermal conductivity (30 mW/m·K), and excellent thermal radiation reflectivity (90%). By simulating the actual high-temperature and high-humidity environment, 10-mm-thick H-ZSNFMs can reduce the heat source from 1365 to 380 °C and maintain complete hydrophobicity even in a water vapor environment of 350 °C. This means that it has superior insulation and waterproof performance even in a high-temperature water environment. For firefighting clothing, H-ZSNFM displayed waterproof and insulation layers, which have excellent thermal protection performance and achieve incompatibility between water and fire, providing valuable time for fire rescue and a safety line of defense for emergency personnel. This design strategy with mechanical robust and hydrophobic temperature resistance applies to the development of many other types of high-performance thermal insulation materials and presents a competitive material system for thermal protection in extreme conditions.
研究领域:
材料科学
·
热防护技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF NUCLEAR MATERIALS
·
2025
·
IF 3.2
Liang Cai,Shurui Shang,Haifeng Xue,Xin Hu,Qiang Qi,Guangna Luo,Yingchun Zhang
Li 2 TiO 3 -Li 4 SiO 4 biphasic ceramic has attracted increasing attention because of its unique advantages for tritium breeding in fusion reaction. To overcome the critical limitations of conventional Li 2 TiO 3 -Li 4 SiO 4 pebbles, particularly their inadequate mechanical strength and low packing density, this work developed high-performance Li 2 TiO 3 -Li 4 SiO 4 cubic units via digital light processing (DLP). The purge gas flow behavior in stacked cubic unit structure was studied by Computational Fluid Dynamics (CFD) method to evaluate its structural characteristics. The photosensitivity and rheological properties of precursor suspension were studied to verify the printing feasibility. Solid loading and sintering process were optimized to yield the defect-free Li 2 TiO 3 -Li 4 SiO 4 cubic unit. The results show that the purge gas had periodic velocity distribution and extremely low pressure drop in the stacked cubic unit structure. Li 2 TiO 3 -Li 2 SiO 3 -Li 2 CO 3 ceramic suspension possessed suitable photosensitivity and thixotropy, and its optimal solid loading was 40 vol%. After sintering at 1100 °C, the Li 2 TiO 3 -Li 4 SiO 4 cubic unit with high relative density (92.8 %TD), high crush load (2000.3 N) and favorable open-pore structure can be prepared. Comparative analyses of Li-based cubic units indicate that the Li 2 TiO 3 -Li 4 SiO 4 cubic unit not only addresses the limitations of single-phase variants but also demonstrates superior intrinsic characteristics, including excellent mechanical& thermomechanical properties and distinct hydrogen isotope release behavior. This work proves the feasibility of Li 2 TiO 3 -Li 4 SiO 4 biphasic strategy and potential of Li 2 TiO 3 -Li 4 SiO 4 cubic units for the future tritium breeding design.
研究领域:
材料科学
·
核工程
·
增材制造
·
陶瓷材料
·
聚变能源
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）