CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Qing Wang,Ziyang Ruan,Jianyu Li,Zifan Zhao
Yttrium aluminum garnet (Y 3 Al 5 O 12 , YAG) is regarded as a candidate of thermal barrier coating material for its excellent thermal stability and corrosion resistance, yet the poor fracture toughness and the low thermal expansion coefficient are the roadblock that limits its application. In order to improve the fracture toughness and the thermal expansion coefficients, a series of Y 3 Al 5 O 12 composite ceramics toughened by ferroelastic LaAlO 3 second phase were prepared by in-situ synthesis method in this work. The prepared x LaAlO 3 /(1- x )Y 3 Al 5 O 12 composite ceramics ( x =10∼50%) exhibit superior fracture toughness (2.16 MPa·m 0.5 ∼2.63 MPa·m 0.5 ) with respect to single-phase Y 3 Al 5 O 12 (1.94 MPa·m 0.5 ), which is mainly attributed to the synergistic effects of ferroelastic toughening of second phase, residual stress toughening, and fine-grain strengthening. On the account of the synergistic effects of three toughening mechanisms, 0.2LaAlO 3 /0.8Y 3 Al 5 O 12 composite ceramic manifest the strongest fracture toughness (2.63 MPa·m 0.5 ), which is 36% improved compared with single-phase Y 3 Al 5 O 12 . In addition, the thermal expansion coefficients of x LaAlO 3 /(1- x )Y 3 Al 5 O 12 specimens (9.54∼9.97 × 10 -6 K -1 at 1200 °C) are larger than that of Y 3 Al 5 O 12 (9.25 × 10 -6 K -1 at 1200 °C). Especially, 0.5LaAlO 3 /0.5Y 3 Al 5 O 12 specimen exhibits the highest thermal expansion coefficient (9.97×10 -6 K -1 at 1200 °C), which improve by 7.78% compared to single-phase Y 3 Al 5 O 12 . The improved fracture toughness and the capable thermal expansion coefficients of LaAlO 3 /Y 3 Al 5 O 12 composite ceramics renders their promising aspect for thermal barrier coating application.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2021
·
IF 7.514
Umarbek Alimov,Kaiyu Zhao,Jiayin Hu,Yafei Guo,Lingzong Meng,Xiuyun Pan,Tianlong Deng
The purpose of this exploration was to determine the density and volumetric properties of the aqueous solution of Na 2 H 2 P 2 O 7 with the molality varied from 0.08706 to 0.88402 mol·kg −1 measured at temperature intervals of 5 K from 283.15 to 363.15 K at 101.325 kPa using Anton Paar Digital vibrating-tube densimeter. The thermal expansion coefficient ( α ), apparent molar volume ( V Φ ), expansibility ( ϕ E ), and partial molar volume ( V B ) of Na 2 H 2 P 2 O 7 (aq) against temperature and molality have been evaluated from density data. On the basis of Pitzer ion-interaction apparent molar volume theory, the Pitzer single-salt parameters ( β M , X 0 v , β M , X 1 v , β M , X 2 v and C M , X v , MX = Na 2 H 2 P 2 O 7 ), and their correlation coefficients a i of the temperature-dependence formula f ( i , p , T ) = a 1 + a 2 ln( T /298.15) + a 3 ( T − 298.15) + a 4 /(620 – T ) + a 5 /( T − 227) for Na 2 H 2 P 2 O 7 were obtained for the first time. It was revealed that predicted apparent molar volumes agreed well with the experimental values indicating the single salt parameters and the temperature-dependent formula are reliable.
研究领域:
物理化学
·
无机化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2024
·
IF 3.5
Mengting Jiang,Xiaopeng Li,Tengfei Deng
In this study, aluminum titanate/anorthite (Al 2 TiO 5 -CaAl 2 Si 2 O 8 ) ceramics were fabricated from ferrotitanium slag through phase reconstruction. Stabilization of the ceramic was achieved by migration of Mg element into Al 2 TiO 5 phase. The results indicated that optimal performance was achieved with the addition of 4 wt% MgO and 60 wt% ferrotitanium slag at 1370°C. The ceramic exhibited bulk density of 3.11 ± 0.01 g/cm 3 , thermal storage density of 1.51 kJ/cm 3 , and thermal expansion coefficient of 3.40 × 10 −6 /°C (1000°C), respectively. Additionally, the solid solution of Mg 2+ in the Al 2 TiO 5 lattice reduced the formation of microcracks and enhanced the mass transfer process. Consequently, the sintering temperature decreased from 1415°C to 1370°C while the bending strength increased from 61.25 ± 1.05 MPa to 75.92 ± 7.72 MPa. Furthermore, finite element simulation demonstrated that higher thermal expansion led to concentrated thermal stress, potentially increasing the possibility of ceramic cracking. This research provides a new strategy for preparing low thermal expansion ceramics from titanium-containing solid waste.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS & DESIGN
·
2019
·
IF 5.77
Yuxuan Wang,Jie Sheng,Lidong Wang,Yu Zhao,Miao Wang,Ziyue Yang,Han Xue,Weidong Fei
Ferroelectric ceramic with negative thermal expansion during the phase transformation from T-phase to C-phase can be used as reinforcement to obtain low thermal expansion metal matrix composites. Interface bonding plays an important role in determining thermal and mechanical properties of the composites. Here, we designed and applied Cu 2 O coating on the surface of Sr 0.2 Ba 0.8 TiO 3 (SBT) particles by heterogeneous precipitation method, and subsequently obtained low thermal expansion Cu 2 O/SBT/Cu composites with excellent mechanical properties. It was found that the semi-coherent relationship can be formed in both Cu/Cu 2 O and Cu 2 O/SBT interfaces, which benefits the reduction of composites thermal expansion. The relationship among Cu 2 O content, SBT phase transformation and thermal expansion has been discussed. Compared with SBT/Cu composite, the average coefficient of thermal expansion of 6%Cu 2 O/SBT/Cu composite can be reduced from 12.97 × 10 −6 °C −1 to 11.44 × 10 −6 °C −1 . Moreover, with the introduction of Cu 2 O coating, the compressive strength of the composite can reach up to 722.7 MPa. This work provides a promising method to improve the thermal expansion and mechanical property of ferroelectric reinforcement metal matrix composites.
研究领域:
材料科学
·
复合材料
✓ 已验证
DOI
高影响因子
Materials Research Express
·
2019
·Vol. 6
·期 5
·056547
·
IF 1.449
Yinqun Hua,Bochen Jiang,Ruifang Chen,Jiangdong Cao,Wenwen Shuai,Ruitao Li
In this study, Gd2Zr2O7 -X TiSi2 (X = 0, 2.5, 5 and 7.5 wt% TiSi2) ceramics were synthesized by solid state reaction method at 1550 °C for 12 h in air. The influences of TiSi2 content on the phase, microstructure, thermophysical properties, hardness and fracture toughness were investigated. Gd2Zr2O7- X TiSi2 (X = 7.5 wt%) ceramic mainly consists of a defect fluorite phase; while Gd2Zr2O7 -X TiSi2 (X = 0, 2.5 and 5 wt% TiSi2) ceramics have an ordered pyrochlore phase. In addition, the degree of structural order decreased with the increasing TiSi2 content. The microstructure of the doped ceramic materials exhibited grain refinement. The doping of TiSi2 decreased the thermal conductivity while improved the thermal expansion coefficient, the hardness and the fracture toughness enhanced significantly. With these improved properties, the TiSi2 doped Gd2Zr2O7 ceramic materials can be a very promising material for ceramic layers of thermal barrier coating.
研究领域:
材料科学
·
热障涂层研究
✓ 已验证
产品关联
DOI
高影响因子
Materials Research Express
·
2020
·Vol. 7
·期 1
·015204
·
IF 1.929
Ying Zhou,Guoyou Gan,Zhenhua Ge,Jing Feng
SmTaO4, Sm3TaO7 and SmTa3O9 ceramics were prepared via a high temperature solid-state reaction. The results show that the phase structures of the SmTaO4 ceramics are a monoclinic phase (space group: I2 (5)), the Sm3TaO7 ceramics are an ordered orthorhombic phase (space group: Ccmm), and the SmTa3O9 ceramics are an orthorhombic phase (space group: Cmmm). Macromolecular and crystal structures of Sm3TaO7 and SmTa3O9 are more complex than those of SmTaO4, which can enhance phonon scattering and reduce thermal conductivity. Compared with those of SmTaO4 and SmTa3O9, Sm3TaO7 has the smallest grain size, indicating that a small grain size has an effect on strength and ensures material stability. Because of a distorted TaO6 octahedron and a high concentration of cation vacancy in the lattice of SmTa3O9, its thermal conductivity increases with increasing temperature. Compared with that of 7–8 YSZ, Sm3TaO7 has a low thermal conductivity (1.3–1.7 W·m−1·K−1 at 100 °C–900 °C), and its minimum thermal conductivity is nearly 30% lower than that of YSZ. The Sm3TaO7 ceramics have the highest TECs at approximately 9.82 × 10−6 K−1 at 1200 °C, which is close to that of 7–8 YSZ (approximately 10 × 10−6). This indicates that Sm3TaO7 has the potential to be employed as a thermal barrier coating.
研究领域:
材料科学
·
热物理学
✓ 已验证
产品关联
DOI
高影响因子
Acta Geochimica
·
2023
·Vol. 42
·期 6
·988-997
·
IF 1.6
Song Jiamei,Fan Dawei,Huang Shijie,Zhang Shanrong,Wu Mengzeng,Chen Wei,Zhou Wenge
The unit-cell parameters and volumes of geikielite (MgTiO 3 ) and ilmenite (FeTiO 3 ) were investigated at high temperatures up to 700 K and ambient pressure, using in-situ angle-dispersive synchrotron X-ray diffraction. No phase transition was detected over the experimental temperature range. Using (Berman in J Petrol 29:445–522, 1988. 10.1093/petrology/29.2.445) equations to fit the temperature-volume data, the volumetric thermal expansion coefficients at ambient conditions ( α V 0 ) of MgTiO 3 and FeTiO 3 were obtained as follows: 2.55 (6) × 10 –5 K −1 and 2.82 (10) × 10 –5 K −1 , respectively. We infer that the larger effective ionic radius of Fe 2+ (VI) (0.78 Å) than that of Mg 2+ (VI) (0.72 Å) renders FeTiO 3 has a larger volumetric thermal expansivity than MgTiO 3 . Simultaneously, the refined axial thermal expansion coefficients under ambient conditions are α a 0 = 0.74 (3) × 10 –5 K −1 and α c 0 = 1.08 (5) × 10 –5 K −1 for the a -axis and c -axis of MgTiO 3 , respectively, and α a 0 = 0.95 (5) × 10 –5 K −1 and α c 0 = 0.92 (12) × 10 –5 K −1 for the a -axis and c -axis of FeTiO 3 , respectively. The axial thermal expansivity of MgTiO 3 is anisotropic, but that of FeTiO 3 is nearly isotropic. We infer that the main reason for the different axial thermal expansivity between MgTiO 3 and FeTiO 3 is that the thermal expansion mode of the Mg-O bond in MgTiO 3 is different from that of the Fe–O bonds in FeTiO 3 .
研究领域:
材料科学
·
矿物学
·
固体物理
·
X射线衍射
·
热性能
✓ 已验证
DOI
高影响因子
Coatings
·
2024
·Vol. 14
·期 9
·1097
·
IF 2.9
Jiaxin Liao,Lin Chen,Luyang Zhang,Xunlei Chen,Cheng Xu,Tianyu Li,Jing Feng
Environmental barrier coatings (EBCs) are widely used to protect ceramic matrix composites (CMCs, SiCf/SiC, and Al2O3f/Al2O3), and they should have low thermal expansion coefficients (TECs) matching the CMCs and excellent mechanical properties to prolong their lifetime. Current EBC materials have disadvantages of phase transitions and insufficient mechanical properties, which affect their working temperatures and lifetime. It is necessary to develop new oxide EBCs. Ytterbium tantalate (YbTaO4) is a stable and novel EBC material, and we have improved the mechanical properties and TECs of Yb1−xAlxTaO4(x = 0.05, 0.1, 0.2, 0.3, 0.4, 0.5) ceramics by replacing Yb with Al. XRD, SEM, and EDS are used to verify the crystal and microstructures, and nano-indentation is used to measure the modulus and hardness when changes in TECs are measured within a thermal expansion device. The results show that the phase structure of Yb1−xAlxTaO4(x = 0.05, 0.1, 0.2, 0.3, 0.4, 0.5) is stable at 25–1400 °C within air atmosphere, and their high-temperature TECs (6.4–8.9 × 10−6K−1, 1400 °C) are effectively regulated by introductions of different contents of Al, which enlarge their engineering applications for SiCf/SiC and Al2O3f/Al2O3CMCs. The evolutions of TECs are analyzed from structural characteristics and phase compositions, and the increased TECs make Yb1−xAlxTaO4potential EBCs for Al2O3matrixes. Due to the high bonding strength of Al–O bonds, hardness, as well as Young’s modulus, are enhanced with the increasing Al content, with Yb1−xAlxTaO4(x = 0.05, 0.1, 0.2, 0.3, 0.4, 0.5) having a nano-hardness of 3.7–12.8 GPa and a Young’s modulus of 100.9–236.6 GPa. The TECs of YbTaO4are successfully regulated to expand their applications, and they match those of Al2O3and SiC matrixes, as well as displaying improved mechanical properties. This work promotes applications of YbTaO4as potential EBCs and provides a new way to regulate the TECs of tantalates.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2021
·
IF 4.598
Haoji Lao,Nafeesa Mushtaq,Guofei Chen,Bingyang Wang,Yuxia Ba,Xingzhong Fang
Two new series of transparent polyamide-imides (PAIs) with high modulus and low coefficient of thermal expansion (CTE) were prepared by random or block copolymerization of 4,4′-biphthalic dianhydride (BPDA) and p -phthaloyl chloride (TPC) with 2,2′-bis(trifluoromethyl)benzidine (TFDB). These series of PAIs displayed low CTE of 16–42 ppm/K, good mechanical properties with high tensile modulus ranging from 4.9 to 6.6 GPa, tensile strengths of 112–170 MPa and elongations at break of 2.0–5.4%, as well as high transparency with transmittances at 500 nm (T 500nm ) of 84–87%, which was greatly affected by the feed ratio of monomer BPDA & TPC, and the block length caused by block polymerization. The block copolymer PAI-3-B1 presented the best comprehensive performance with high transparency (T 500nm ) of 87%, low CTE of 16 ppm/K and high tensile modulus of 6.1 GPa.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Sehreish Abrar,Zhuang Ma,Ling Liu,Faisal Nazeer,Abdul Malik
The materials which have low thermal conductivity , a good match of coefficient of thermal expansion with SiC-based ceramics matrix composites (CMCs) and excellent resistance against calcium-magnesium-alumina-silicate (CMAS) are suitable candidates for thermal/environmental barrier coating. To fulfil the above requirements we developed a new multicomponent rare earth (Y 0.2 Dy 0.2 Er 0.2 Yb 0.2 Ho 0.2 ) 2 Si 2 O 7 or (5RE 0.2 ) 2 Si 2 O 7 high entropy ceramics pyrosilicate by a single step solid solution method. The x-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis revealed that the as-fabricated bulk composite (5RE 0.2 ) 2 Si 2 O 7 has a single phase β-type structure match well with single rare earth ytterbium disilicate (Yb 2 Si 2 O 7 ) and the different rare earth oxides mixed well with each other. The excellent coefficient of thermal expansion (4 × 10 −6 -5 × 10 −6 °C −1 ) and ultra-low thermal conductivity (0.7–1.6 W/m C) was observed as compared to other single and multicomponent high entropy ceramics composites. The (5RE 0.2 ) 2 Si 2 O 7 ceramics pyrosilicate show an excellent CMAS resistance at various temperatures (1300, 1400, and 1500) °C for 4 h compared with single principle RE disilicates. The above all mentioned results identify that this material is a suitable candidate for coating on the SiC-based ceramics composite for thermal/environmental barrier coating.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
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 THE EUROPEAN CERAMIC SOCIETY
·
2021
·
IF 5.302
Xudong Wang,Ke Chen,Erxiao Wu,Yiming Zhang,Haoming Ding,Nianxiang Qiu,Yujie Song,Shiyu Du,Zhifang Chai,Qing Huang
Thermal expansion of MAX phases along different directions tends to be different because of the anisotropy of hexagonal crystals. Herein, a new Hf 2 SeC phase was synthesized and confirmed to be relatively isotropic, and the coefficients of thermal expansion (CTEs) along a and c directions were determined to be 9.73 μK −1 and 10.18 μK −1 , respectively. The strong MS bond endowed Hf 2 SC and Zr 2 SC lower CTEs than those of Hf 2 SeC and Zr 2 SeC. The relationship between the thermal expansion anisotropy and the ratio of elastic stiffness constant c 11 and c 33 was established. This straightforward approximation can be used to roughly predict the thermal expansion anisotropy of MAX phases.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）