International Journal of Applied Ceramic Technology
·
2022
·Vol. 20
·期 3
·1855-1864
·
IF 2.328
Shi Fu,Zengchao Yang,Honghua Li,Liang Wang,Yong Li,Jiangtao Li
Si 3 N 4 ceramics were prepared by gas pressure sintering at 1900°C for 12 h under a nitrogen pressure of 1 MPa using Gd 2 O 3 and MgSiN 2 as sintering additives. The effects of the Gd 2 O 3 /MgSiN 2 ratio on the densification, microstructure, mechanical properties, and thermal conductivity of Si 3 N 4 ceramics were systematically investigated. It was found that a low Gd 2 O 3 /MgSiN 2 ratio facilitated the thermal diffusivity of Si 3 N 4 ceramics while a high Gd 2 O 3 /MgSiN 2 ratio benefited the densification and mechanical properties. When the Gd 2 O 3 /MgSiN 2 ratio was 1:1, Si 3 N 4 ceramics obtained an obvious exaggerated bimodal microstructure and the optimal properties. The thermal conductivity, flexural strength, and fracture toughness were 124 W·m −1 ·k −1 , 648 MPa, and 9.12 MPa·m 1/2 , respectively. Comparing with the results in the literature, it was shown that Gd 2 O 3 -MgSiN 2 was an effective additives system for obtaining Si 3 N 4 ceramics with high thermal conductivity and superior mechanical properties.
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
Yun Liu,Ruixiang Liu,Yuanhang Zheng,Jixue Zhao,Tianyi Sui,Xiaolei Li,Bin Lin
To investigate the mechanism of the influence of the sintering additive ratio on the microstructure evolution of silicon nitride (Si 3 N 4 ) ceramics, Si 3 N 4 ceramics were prepared by gas pressure sintering using different ratios of Y 2 O 3 /MgSiN 2 as additives. Varying the ratio of Y 2 O 3 /MgSiN 2 changed the composition of the liquid phase, thereby affecting the densification process and phase transformation rate of Si 3 N 4 ceramics, and ultimately changing their microstructure. The reduction in the Y 2 O 3 /MgSiN 2 ratio raised the N/O and Si/O ratios in the system, which increased the liquid phase viscosity. The Si 3 N 4 grain distribution varied from "normal to bimodal". In the case of increasing the proportion of MgSiN 2 and prolonging the sintering time, more of the glass phase evaporated, which reduced the content of the low thermal conductivity phase and increased the continuity of Si 3 N 4 /Si 3 N 4 . Therefore, Si 3 N 4 ceramics with 1 wt% Y 2 O 3 and 5 wt% MgSiN 2 exhibited excellent properties after sintering at 1900 °C for 12 h, with thermal conductivity, bending strength , and fracture toughness of 106.7 Wm −1 K −1 , 776 MPa, and 11.66 MPa m 1/2 , respectively.
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
·
2024
·
IF 5.1
Xuanzhi Chen,Yehua Li,Yujie Qi,Pengjin Huang,Haidong Wu,Xin Deng,Shanghua Wu
In this study, self-synthesized Gd 3 Si 2 C 2 and MgO were used as sintering aids to fabricate Si 3 N 4 ceramics via gas-pressure sintering. The results indicated that Gd 3 Si 2 C 2 reacted with inherent SiO 2 on the Si 3 N 4 surface to form Gd 2 O 3 and β-Si 3 N 4 in situ, thereby increasing the N/O ratio of the liquid phase. In addition, in situ β-Si 3 N 4 induced grain growth, enhancing the thermal conductivity of Si 3 N 4 ceramics while maintaining excellent mechanical properties. Compared to the samples with Gd 2 O 3 and MgO as sintering aids, those with Gd 3 Si 2 C 2 and MgO as sintering aids demonstrated superior overall performance with the thermal conductivity, bending strength, fracture toughness, and Vickers hardness of 101.96 W⋅m −1 ⋅K −1 , 848.26 ± 4.66 MPa, 6.23 ± 0.15 MPa⋅m 1/2 , and 16.56 ± 0.43 GPa, respectively.
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
International Journal of Applied Ceramic Technology
·
2024
·
IF 1.8
Jixue Zhao,Yun Liu,Yuanhang Zheng,Xiaolei Li,Tianyi Sui,Bin Lin
In this paper, high thermal conductivity Si 3 N 4 ceramics were successfully fabricated through exploring and optimizing the tape casting process. The impact of various organic additives on the rheological characteristics of Si 3 N 4 slurry was explored, and the pore size distribution and microstructure of the green tapes at different solid loadings were investigated, as well as the microstructure of Si 3 N 4 ceramics. Green tapes with a narrow pore size distribution, a small average pore size, and a high density of 1.88 g cm −3 were prepared by the investigation and optimization of the Si 3 N 4 slurry formulation. After gas pressure sintering, Si 3 N 4 ceramics with a density of 3.23 g cm −3 , dimensions of 78 mm × 78 mm, and a thickness of 0.55 mm were obtained. The microstructure of the Si 3 N 4 ceramics showed a bimodal distribution and a low content of glassy phases. The thermal conductivity of the Si 3 N 4 ceramics was 100.5 W m −1 K −1 , the flexural strength was 735 ± 24 MPa, and the fracture toughness was 7.17 MPa m 1/2 .
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2015
·
IF 2.605
Chi Zhang,Xiumin Yao,Yinsheng Li,Hanqin Liang,Jian Chen,Jingxian Zhang,Jian Yang,Xiaoyun Li,Tai Qiu,Zhongming Chen,Xuejian Liu,Zhengren Huang
Dense silicon carbide ceramics with 0.5–10 wt% AlN additions were pressureless densified by two steps sintering using B 4 C and C as sintering additives. The effects of AlN content on density, microstructure and thermal conductivity of SiC–AlN composites were investigated. SiC ceramics can be well densified in the presence of AlN. The phonon scattering mechanism and the Klemens–Callaway theory were used to calculate the thermal conductivity evolution of SiC ceramics result from the dissolved Al and N atoms. The main reason for the degradation of thermal conductivities is the point defect scattering dominated by the differences in size and interatomic forces between impurity and host atoms.
研究领域:
材料科学
·
热传导工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
·
IF 5.7
Chuang-Tian Zhan,Sheng-Jin He,Wei-Ming Guo,Yuan-Bin Chen,Shi-Kuan Sun,Hua-Tay Lin
Combined with the thickness control of interlayers (∼10 µm and ∼60 µm), SiC nano-powders with Al 2 O 3 -Y 2 O 3 -MgO-CaO additive (NITE-SiC) were used as the joining materials to achieve the low-temperature joining of SiC ceramics. Some residual pores were observed in the interlayer with a thickness of ∼60 µm after joining at 1650 ℃, and the shear strength of SiC joints measured was 39.3 ± 5.5 MPa. Observations showed the fracture of joints occurred at the interlayer. When the thickness of the interlayer decreased to ∼10 µm, no cracks or porosity were observed at the interface region after joining at 1650 ℃. The shear strength of SiC joints increased to 69.5 ± 8.9 MPa, and the fracture originated from the matrix. The results demonstrated using NITE-SiC with Al 2 O 3 -Y 2 O 3 -MgO-CaO additive as the joining layer and reducing the thickness of the interlayer could lower the joining temperature and significantly improve the mechanical strength of joints.
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
Transactions of the Indian Ceramic Society
·
2024
·
IF 1.5
Jialu Li,Yuanbing Li,Shujing Li,Kun Xiang
BPO4-B2O3 composite additive enhanced silica ceramics were successfully prepared by solid phase sintering. The effects of BPO4-B2O3 addition and sintering temperature on the microstructure and phase composition and mechanical properties of silica ceramics were analysed by scanning electron microscopy and X-ray diffraction techniques. The results showed that at 1200°-1400°C, BPO4-B2O3 composite additive formed a glass phase in the sample, filled the pores, and improved the sintering densification of the sample. In addition, the addition of 9 wt% BPO4-B2O3 successfully inhibited the crystallization of fused silica, which significantly improved the mechanical strength of silica ceramics. After sintering at 1200°C for 3 h, the apparent porosity of silica ceramics with 9 wt% BPO4-B2O3 was only 1.33%, and the cold modulus of rupture reached a maximum of 60.99 MPa, which was about 35 times that of pure silica ceramics. It is shown that adding BPO4-B2O3 composite additive provides a feasible method for preparing silica ceramics with good mechanical properties.
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 EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Juan Wang,Xiaoyu Wang,Yongzhao Yang,Qianlong Fu,Feng Hu,Zijian Zhang,Shuang Li
Silicon carbide (SiC) ceramic membranes are promising components for the efficient treatment of various wastewaters in membrane-based techniques. However, the high preparation temperature and then the high production cost inhibits their large-scale application. Here, an ultra-low temperature sintering process was proposed to prepare SiC ultrafiltration membrane. When the ceramic membrane was heated at 600 °C in air, a selective layer comprised of α-SiC and β-SiC formed without the emergence of crystalline silica. The thickness of the membrane layers was determined by the solid content and viscosity of the slurry. Well-dispersed SiC grains and homogeneous-distributed pores formed in the selective layers when using 100 nm SiC powders. The water flux and emulsion flux were investigated to verify the permeability of the ceramic membrane. Thus, this work proposes an energy-saving process for the preparation of SiC UF membrane and achieves the preparation of SiC UF membrane at ultra-low temperature.
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
·
2025
·
IF 3.8
Shuo Yan,Yuhong Chen,Ziqiang Yin,Binwei Huang,Quanxing Ren,Tihao Cao,Xuxin Ping,Ruibin Liu,Zhengren Huang,Qing Huang,Yinsheng Li
SiC ceramics were fabricated by spark plasma sintering of β-SiC powder with various rare-earth (RE = La, Gd, Yb, Sc) oxides and magnesia additives. The phase compositions, microstructures, lattice oxygen contents, and thermal conductivities were systematically investigated. A decrease in the cationic radius of rare-earth element resulted in an increased cationic field strength. This enhanced attraction to oxygen anion led to higher viscosity and improved high-temperature stability of the intergranular RE-Mg-Si-O liquid phase. After sintering at 1850°C, influenced by liquid-phase viscosity, the degree of β→α phase transformation in SiC and the grain size decreased with decreasing cationic radius of rare-earth element. After sintering at 2050°C, the liquid-phase viscosity significantly decreased, but volatilization became pronounced. The extent of β→α phase transformation and the grain size were affected by both liquid-phase viscosity and volatility. Larger grain size and higher affinity of rare-earth cations for oxygen anions contributed to reduce lattice oxygen content. The thermal conductivities of the SiC ceramics ranged from 192 to 229 W/mK. Notably, the SiC ceramic with Yb 2 O 3 -MgO additives exhibited the largest grain size, the lowest lattice oxygen content, and the elimination of β/α heterophase boundaries, thereby achieving the highest thermal conductivity of 229 W/mK.
研究领域:
材料科学
·
热传导工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Juan Wang,Xiaoyu Wang,Qianlong Fu,Jinxiu Fu,Fengrui Zhai,Shuang Li
Silicon carbide ceramic membranes have been widely used in the treatment of various corrosive and high temperature wastewaters. However, SiC is a compound with strong covalent bond , thus the sintering temperature and then the energy consumption during sintering of SiC ceramics is high, which inhibits the scale-up manufacturing of SiC ceramic membranes . Here, a silicon carbide ceramic membrane support was prepared at 800 °C with a low melting-point glaze as the sintering aid. The glaze infiltrated the SiC skeleton during sintering, and gave rise to high fracture strength of the porous ceramics . With the content increase of sintering aid from 10 wt% to 30 wt%, the pore-formation mechanism of the ceramic membrane support transformed from SiC particles packing to SiC aggregations packing, leading to the increase in pore size and decrease in porosity. The permeance and selectivity of the support was investigated via pure-water and oil-in-water emulsion tests. Due to the high hydrophilicity, the pure-water flux increased from 32 L/(m 2 ·h) to 87 L/(m 2 ·h) while the oil rejection decreased from 99.0% to 93.1% with the increase of trans -membrane pressure. This work provides a feasible route for the preparation of SiC porous ceramics with low energy consumption.
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
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Qianlong Fu,Yongzhao Yang,Juan Wang,Feng Hu,Shuang Li,Yang Zhao
The rapid development of additive manufacturing techniques enables the preparation of SiC ceramics with complex configurations; however, the high sintering temperature and defects-control are still great challenges during processing. Thus, SiC ceramics were prepared by digital light processing followed by liquid phase sintering using Al 2 O 3 –Y 2 O 3 additives in this study. The photopolymerization of the SiC slurry, microstructures and mechanical properties of the sintered ceramics were investigated. The Al 2 O 3 –Y 2 O 3 additives enhanced the curing ability of the photosensitive SiC slurries by reducing the absorbance and scattering of UV light. The liquid phase accelerated the densification of the ceramics by particles rearrangement and interfacial bonding. Thus, the flexural strength of the ceramics increased from 41.0 MPa to 62.8 MPa with sintering temperature increasing.
研究领域:
材料科学
·
制造工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2020
·Vol. 35
·期 3
·506-513
·
IF 0.64
Tan Lin,He Qianglong,Hu Lanxin,Tian Tian,Wang Weimin
Silicon carbide ceramics with different thicknesses/diameter ratios were prepared by using ultra-fine silicon carbide powder with the sintering additives of 1.0 wt% boron and 1.5 wt% carbon. The influence of thickness/diameter ratio on the microstructure and density of SiC ceramics was investigated in detail. The experimental results show that the addition of boron and carbon sintering aids can promote the densification process of SiC ceramic, leading to the low sintering temperature and improve mechanical properties. At 1950 °C, SiC ceramic with a density of 99% exhibits Young’s modulus, hardness, and flexural strength of 476 MPa, 28.3 GPa, and 334 MPa, respectively. It is found that long holding time has a positive effect on the uniformity of the microstructure and density distribution of SiC ceramics with large thickness/diameter ratios. Additionally, the sintering additive of boron can solid-solve into SiC, and then facilitate the phase transformation of SiC to form 6H-SiC and 4H-SiC composite ceramics.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）