CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Yao Liu,Lina Zhan,Yu He,Jun Zhang,Jianjun Hu,Lijin Cheng,Qiumei Wu,Shaojun Liu
Photocurable gray-colored Si 3 N 4 ceramic slurry with high solid loading, suitable viscosity and high curing depth is critical to fabricate dense ceramic parts with complex shape and high surface precision by stereolithography technology. In the present study, Si 3 N 4 ceramic slurry with suitable viscosity, high solid loading (45 vol %) and curing depth of 50 μm was prepared successfully when surface modifier KH560 (1 wt%) and dispersant Darvan (1 wt%) were used. The slurry exhibits the shear thinning behavior. Based on the Beer-Lambert formula, D p ( the attenuation length) and E c (the critical energy dose) of Si 3 N 4 ceramic slurry with solid loading of 45 vol % were derived as 0.032 mm and 0.177 mJ/mm 2 , respectively. Si 3 N 4 ceramic green parts with complex shape and high surface precision were successfully fabricated by stereolithography technology. After optimizing the debinding and sintering process for green parts, dense Si 3 N 4 ceramics with 3.28 g/cm 3 sintering density were fabricated. The microhardness and fracture toughness of as-sintered Si 3 N 4 ceramics are ~14.63 GPa and ~5.82 MPa m 1/2 , respectively, which are comparable to those of the samples by traditional dry-pressed and pressureless sintering technology. These results show that ceramic stereolithography technology could be promising to fabricate high performance ceramics, especially for gray-colored monolithic Si 3 N 4 ceramics.
研究领域:
材料科学
·
先进制造
✓ 已验证
产品关联
DOI
高影响因子
Nano Research
·
2023
·
IF 9.9
Tong Zongwei,Yan Xiangjie,Wang Yuexiang,Li Kexun,Ma Weihai
Increasing porosity is one of the most direct ways to improve the thermal insulation and dielectric properties of materials. Until now, many wet methods for preparing Si 3 N 4 ceramic foams usually face the problems of complex rheology, long period, and expensive cost, and the reported pore sizes of Si 3 N 4 ceramic foams are typically micron-grade, resulting in a lack of competitiveness in thermal insulation and wave-transparent applications. In this paper, the Si 3 N 4 @SiO 2 ceramic foams were prepared using an efficient dry-method, which combined three processes of low temperature chemical vapor deposition (LTCVD), template, and isostatic pressing. The method has the advantages of simple operation and short preparation period, and can realize near-net size molding and mass production. In addition, the evolution mechanisms of honeycomb microstructure and composition of Si 3 N 4 @SiO 2 ceramic foam during sintering were studied by chemical reaction thermodynamics. The as-prepared Si 3 N 4 @SiO 2 ceramic foam possesses low density (0.377 g·cm −3 ), high compressive strength (7.5 MPa), low thermal conductivity (0.0808 W·m −1 ·K −1 ), and excellent dielectric properties ( ε < 1.32, tan δ < 0.009) in the frequency range of 8–18 GHz, and its maximum working temperature in air can reach up to 1100 °C. It will be recommended to be applied in the interlayer of Si 3 N 4 ceramic radome to improve its thermal insulation and electromagnetic wave transparency performances.
研究领域:
材料科学
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陶瓷工程
·
热能工程
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
Materials Express
·
2020
·Vol. 10
·期 6
·928-933
·
IF 1.65
Tian Liang,Hou Qinglin,Wang Yingxia,Hou Yihui
Si3N4 ceramic has excellent properties such as high temperature resistance, high hardness, and high thermal stability, but it has the disadvantages of high hardness and brittleness and difficulty in later processing. In this paper, ZrO2 was used as toughening
phase, and ZrO2 toughened Si3N4 ceramics was prepared by injection molding. The effects of ZrO2 sintering temperature and content on the mechanical properties and fracture morphology were studied. Experiments show that when the ZrO2 content
is 10 wt.% and the sintering temperature reaches 1650 °C, the bending strength and fracture toughness of Si3N4 ceramics reach the maximum at the same time, which are 767 MPa and 8.7 MPa·m1/2, respectively. The density is high. XRD analysis revealed
that if the sintering temperature is too high, the ZrO2/Si3N4 system will generate a large number of ZrN impurity phases that cannot be phase-transformed, which ultimately affects the ceramic properties. According to fracture morphology, the toughening mechanism
of ZrO2 is stress-induced phase transition.
研究领域:
材料科学
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2019
·Vol. 16
·期 6
·2173-2180
·
IF 1.074
Ming-Ye Yang,Bin-Bin Dong,Fei-Hong Wang,Xin Xu,Simeon Agathopoulos
This paper reports on the successful fabrication of α -Si 3 N 4 -nanowire/Y 2 Si 2 O 7 composite membranes with superhydrophobic properties, aiming to achieve a high performance in membrane distillation. The starting powder mixture of 87 wt% γ -Y 2 Si 2 O 7 , 5 wt% Si, 3 wt% LiYO 2 , and 5 wt% ferrocene catalyst was dispersed in a stable suspension, and after being tape-casted, it was sintered at 1300°C for 4 hours in order to obtain the composite membrane. α -Si 3 N 4 nanowires with a diameter of about 50 nm were formed, distributed uniformly on the surface and in the pores of the membrane and their presence greatly favored superhydrophobicity. After surface modification with a robust hydrophobic layer of SiNCO nanoparticles, strongly adhered to the surface of the produced membrane, a water contact angle of 153 o , was measured. Water desalination experiments, using a sweeping gas membrane distillation (SGMD) device, were conducted. High water flux of 11.91 L/m 2 /h was achieved for a 4 wt% NaCl feeding solution at 90°C. Stable water flux and rejection rates were recorded in long-term experiments (>500 hours) using the produced superhydrophobic composite membrane.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2023
·Vol. 107
·期 1
·16-23
·
IF 3.9
Shuo Zhao,Songmo Du,Siyuan Sun,Fei Li,Zhanglin Chen,Shijia Zhang,Xiaoshan Ning,Wenbin Cao,Kexin Chen,Konstantin Smirnov,Jie Zhang,Guanghua Liu
β-Si 3 N 4 powder with well-dispersed spherical particles was synthesized by liquid-phase modified carbothermal reduction and nitridation. The influence of the type and content of additives on the particle morphology was investigated. The liquid phase formed at the reaction temperature modifies the morphology of the Si 3 N 4 powder. The Si 3 N 4 products precipitated along the liquid-solid interface, thus forming a spherical morphology and promoting the transformation from α-Si 3 N 4 to β-Si 3 N 4 . The type of additives has a strong influence on the formation temperature and viscosity of the liquid phase and hence affects the product morphology. In the samples with CaF 2 and CaO additives, sufficient liquid phase occurred and spherical particles were obtained. In the sample with Y 2 O 3 , however, the liquid phase was insufficient due to the higher formation temperature, thus resulting in an irregular particle morphology.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2024
·Vol. 21
·期 6
·3842-3850
·
IF 1.8
Zhen-Quan Liang,Jia-Ji Liang,Jun-Jie Yu,Pei-Bin Cai,Wei-Ming Guo,Hua-Tay Lin
Spark plasma sintering (SPS) is an ultrafast sintering method for the preparation of ceramics and ceramic composites with simple geometrical shapes, with the combined application of uniaxial pressure. This study aims to propose an SPS densification method for Si 3 N 4 ceramic balls without necessitating alterations to tools and equipment. The Si 3 N 4 ceramic balls intended for sintering are positioned within a SiC powder bed inside the conventional die used in SPS. The study systematically investigates the effects of presintering temperature (1400°C, 1500°C, and 1600°C) and SPS temperature (1600°C, 1700°C, and 1800°C) on the sphericity, relative density, phase composition, microstructure, and mechanical properties of Si 3 N 4 ceramic balls. Experimental findings reveal that Si 3 N 4 ceramic balls exhibiting an optimal combination of sphericity (0.94 ± 0.02), relative density (98.4%), and mechanical properties (Vickers hardness: 17.5 ± 0.4 GPa, fracture toughness: 6.4 ± 0.1 MPa·m 1/2 ) were successfully achieved at a pre-sintering temperature and SPS temperature of 1600°C, coupled with the use of a SiC powder bed and SPS method. Consequently, the SPS method demonstrates its capability to fabricate Si 3 N 4 ceramic balls with excellent performance.
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
·
2025
·
IF 5.6
Suo-Cheng Song,Jiao-Qian Xu,Xu Hao,Xiao-Nan Zhou,Jia-Xin Li,Yong-Mei Hou,Ya-Nan Wang,Qiao-Gen Zhang,Jian-Feng Yang,Bo Wang
Si 3 N 4 ceramics with multiple aperture sizes demonstrate significant potential in high-temperature filtration applications. The bio-template method is an effective strategy for fabricating porous ceramics with complex structures. Herein, we successfully utilized nitrogen gas and SiO vapor to perform carbothermal reduction nitridation reactions with carbonized wood, resulting in a biomimetic, anisotropic, high-strength, hydrophobic, high-temperature resistant, and high-purity porous Si 3 N 4 ceramic. During the preparation process, the surface layer of the carbon template is initially converted into α-Si 3 N 4 . Subsequently, with the assistance of sintering aid Y 2 O 3 , α-Si 3 N 4 undergoes a dissolution-precipitation mechanism to form β-Si 3 N 4 whiskers. This process exposes the inner carbon layer, enabling it to react with the gas phase and ensuring complete transformation into Si 3 N 4 . Unlike other preparation methods, this ceramic inherits the highly ordered honeycomb structure of natural wood while self-assembling whalebone-like β-Si 3 N 4 nanowhisker arrays on elongated channel walls, achieving an exceptional flexural strength value of 32.7 MPa. Furthermore, this lightweight ceramic not only holds promise for oil-water separation but also exhibits outstanding thermal conductivity (7.6 W m −1 K −1 ) and excellent gas permeability ( k 1 = 0.20 × 10 −12 m 2 , k 2 = 1.84 × 10 −8 m) due to its longitudinally aligned microchannels. This ceramic achieves ultra-high filtration efficiency (99 %) for PM 0.5 particles, attributed to the arrangement of whalebone-like whiskers that effectively capture smoke particles and promote nucleation on the whiskers. This work provides a foundation for designing and developing biomimetic structured porous ceramics with multifunctional properties.
研究领域:
材料科学
·
仿生学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
SCRIPTA MATERIALIA
·
2022
·
IF 6.302
Jingkun Xu,Zetan Liu,Jie Zhang,Fei Li,Xiaowei Qin,Shan He,Zhipeng Xie
The effects of various DC electric fields (0–167 V/cm) on liquid-phase hot pressing of Si 3 N 4 ceramics were investigated. The application of a DC field promoted the α→β phase transformation of Si 3 N 4 near the cathode while inhibiting it near the anode. As a result, the Si 3 N 4 ceramics with continuously graded microstructures and mechanical properties were in situ fabricated from a homogeneous raw powder. Although the DC field-driven migration of Mg 2+ and Y 3+ ions was recorded, the graded phase transformation phenomenon was linked to the Peltier effect , which led to additional heating at the cathode and cooling at the anode.
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
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2024
·
IF 3.5
Binbin Fan,Zunlan Hu,Shuo Zhao,Dengke Zhao,Bohan Wang,Shijia Zhang,Zhanglin Chen,Songmo Du,Fei Li,Jie Zhang,Feng Hu,Zhipeng Xie,Kexin Chen,Guanghua Liu
Si3N4 ceramics with improved thermal conductivity and mechanical properties were prepared by carbothermal reduction and two-step sintering. The addition of 2 wt% C led to the development of an intergranular phase YNSiO2 with reduced oxygen content. Notably, setting the pre-sintering temperature at 1450°C promoted the formation of a rough bimodal morphology within the Si3N4 ceramics. Furthermore, an extended holding period at 1850°C resulted in additional grain growth and the elimination of intergranular phases. The Si3N4 specimens produced at 1450°C for 3 h followed by 1850°C for 8 h, incorporating 2 wt% C, exhibited a notable continuity between Si3N4 grains. The thickness of the grain boundary layer was only about 1 nm, and the N/O atomic ratio of the intergranular phase was measured to be 0.42. Consequently, the resulting thermal conductivity, flexural strength, and fracture toughness of Si3N4 specimens were found to be 101 W·m −1 ·K −1 , 712 ± 29 MPa, and 7.7 ± 0.2 MPa·m 1/2 , respectively. Compared with samples without C additive and directly sintered at 1850°C for 8 h, the Si3N4 specimens produced in this work showed a significant increase of more than 50% in thermal conductivity and about 17% in fracture toughness.
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
·
2019
·
IF 3.45
Xuejie Yue,Tao Zhang,Dongya Yang,Fengxian Qiu
Flexible ceramic material, as a fundamental component of a toolset for the design of multifunctional materials, is very desirable, but a simple and effective preparation strategy is still missing. Herein, a flexible Si 3 N 4 /MnO 2 ceramic membrane was fabricated by facile vacuum filtration progress using hard Si 3 N 4 particles and soft ultralong MnO 2 nanowires as building blocks. The Si 3 N 4 particles were uniformly anchored into the porous flexible membrane, depending on the mechanical entanglement from ultralong MnO 2 nanowires, resulting in the excellent interface stability between them. Thanks to the flexibility of MnO 2 nanowires and interface stability, the as-prepared flexible membrane achieves superior flexibility including bending, folding, and twining. The flexible ceramic membrane can broaden the application range beyond the traditional ceramic use as hard structural materials. Moreover, the design strategy developed herein is applicable to other hard ceramic with similar issues.
研究领域:
材料科学
·
纳米技术
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Miao Zhou,Yun Liu,Xiaolei Li,Tianyi Sui,Dong Su,Huiming Ji
Silicon nitride (Si 3 N 4 ) ceramics were prepared by gas-pressure sintering using Y 2 O 3 –MgSiN 2 as a sintering additive. The densification behavior, phase transition, and microstructure evolution were investigated in detail, and the relevance between the microstructure and the performance (including thermal conductivity and mechanical properties) was further discussed. A significant change from a bimodal to a homogeneous microstructure and a decreased grain size occurred with increasing Y 2 O 3 –MgSiN 2 content. When the small quantity of preformed β-Si 3 N 4 nuclei grew preferentially and rapidly in a short time, an obvious bimodal microstructure was obtained in the sample with 4 mol% and 6 mol% Y 2 O 3 –MgSiN 2 . When more β-Si 3 N 4 nuclei grew at a relatively rapid rate, the sample with 8 mol% Y 2 O 3 –MgSiN 2 showed a microstructure consisting of numerous abnormally grown β-Si 3 N 4 grains and small grains. When more β-Si 3 N 4 nuclei grew simultaneously and slowly, there was a homogeneous microstructure and smaller grains in the sample containing 10 mol% Y 2 O 3 –MgSiN 2 . Benefitting from the completely dense, significant bimodal microstructure, low grain boundary phase, and excellent Si 3 N 4 –Si 3 N 4 contiguity, the sample containing 6 mol% Y 2 O 3 –MgSiN 2 exhibited great comprehensive performance, with a maximum thermal conductivity and fracture toughness of 84.1 W/(m⋅K) and 8.97 MPa m 1/2 , as well as a flexural strength of 880.2 MPa.
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
Advanced Materials Interfaces
·
2024
·
IF 4.3
Zaifu Jin,JinHong Li,Jiaqing Zhao,Yixuan Ge
Thermal interface materials (TIMs), which consist of polymers and thermally conductive fillers, are crucial for improving heat dissipation. This study examines the impact of surface functionalization of Si₃N₄ thermal conductive fillers on the performance of TIMs. Si₃N₄ fillers are modified with silane coupling agents of varying alkyl chain lengths, producing fillers with contact angles ranging from 25° to 151.2°, thereby ensuring enhanced interfacial compatibility with various polymers. The modified fillers are incorporated into three common polymers—silica gel (SG), epoxy resin (EP), and polyurethane (PU)—to fabricate TIMs. When the contact angle of Si₃N₄ fillers is 73.3°, they demonstrate excellent interfacial compatibility with EP, leading to a 54.37% increase in thermal conductivity and a 162.75% enhancement in elongation at break for the TIM. At a contact angle of 132.7°, the TIMs prepared with SG exhibit an 86.36% increase in thermal conductivity and a 23.88% increase in elongation at break. Given that the original Si₃N₄ already possesses adequate interfacial compatibility with PU, no further modification is required. These findings offer valuable insights for future research aimed at optimizing Si₃N₄ fillers and TIMs to achieve enhanced thermal and mechanical properties.
研究领域:
材料科学
·
热管理技术
✓ 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）