Crystals
·
2023
·Vol. 13
·期 7
·1099
·
IF 2.7
Li He,Niansheng Huang,Donglin Lu,Pengfei Sheng,Wenjing Zou
Due to its high bonding energy and low self-diffusion coefficient, silicon nitride (Si3N4) ceramics cannot form a dense structure with prolonged high-temperature insulation or by raising the sintering temperature. To improve the density of the sintered Si3N4ceramics, additives are added to promote the rearrangement–dissolution–precipitation process of the crystal grains. However, the liquid phase formation temperature of different sintering aid chemical compositions varies, making it challenging to isolate the mechanism and the effect of liquid phase formation temperatures on sintering. Hence, we developed three sintering aids, namely Y2O3-Al2O3(YA), Y2Si2O7(Y2S), and Y2Si2O7-Al6Si2O13(Y2SM), with homologous elements and different liquid phase formation temperatures. These sintering aids can form a liquid phase with SiO2on the surface of Si3N4at varying temperatures. We analyzed the sintered Si3N4ceramic’s density, volume shrinkage rate, and microstructure to verify the YA’s lower liquid phase formation temperature effect, providing more rearrangement time and increasing sintering density. Conversely, sintering aids with too low liquid phase formation temperatures are more prone to volatilize during high-temperature sintering stages, thereby reducing sintering density. This research found that different liquid phase formation temperatures do not affect the α→β phase transition temperature of Si3N4ceramics. We also evaluated the Y2S sintering aid contents’ effect on Si3N4ceramics sintering. The results revealed that aiding sintering with too little Y2S content is insufficient for liquid phase production, and hence does not improve sintering density. Conversely, excessive liquid phase can improve density and refine grain size but increases weight loss rate during sintering due to volatilization.Keywords:liquid phase sintering;liquid phase formation temperature;sintering aids;silicon nitride sintering
研究领域:
材料科学
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陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Meng Liu,Yong Yang,Yuquan Wei,Yajie Li,Heng Zhang,Xuejian Liu,Zhengren Huang
High-purity SiC materials have been used in semiconductor processes due to their excellent properties. However, they are difficult to densify without sintering aids. In this work, dense and high-purity SiC ceramics have been obtained by pressureless solid-state-sintering with ultra-low contents of sintering additives. The amount of residual B, C and O in the high-purity SiC ceramics was less than 0.15 wt%, respectively, and the total content of other impurity elements (such as aluminum , magnesium, calcium, iron, etc.) was less than 0.015 wt%. Finally, the purity of the as-prepared SiC ceramics was more than 99.5 wt%.
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 REFRACTORY METALS & HARD MATERIALS
·
2018
·
IF 2.606
Te Qi,Zhihao Zhao,Yongqiang Sun,Hangyuan Zhao,Xiaolei Li,Huiming Ji
Porous Si 3 N 4 ceramics with a unique interlocking microstructure have been fabricated by pressureless liquid-phase sintering with YbF 3 and CaF 2 sintering additives at a relatively low temperature (1550 °C). Phase transition and mass diffusion in the low-temperature sintering process are facilitated by YbF 3 and CaF 2 producing plenty of liquid phase owing to their extremely low melting points. As the content of YbF 3 increases from 8.0 wt% to 9.5 wt% and the CaF 2 decreases from 2.0 wt% to 0.5 wt%, the conversion rate of the phase transition from α-Si 3 N 4 to β-Si 3 N 4 increases from 71.1% to 81.2% and the largest average aspect ratio of the β-Si 3 N 4 grains reaches 10.05. At the same time, the porosity declines from 40.4% to 34.9% and the flexural strength increases from 168.5 MPa to 232.1 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
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Xiaole Yu,Xingkai Zhou,Bangze Wu,Bochang Shi,Yaowei Mi,Zhexiang Yu,Zhanheng Jin,Zenan Zhao,Bingyu He,Han Chen,Yifeng Zheng,Lin Ge
Various approaches have been developed to address the challenges of difficult densification in traditional BaZrO 3 -based and BaCeO 3 -based protonic ceramic fuel cells (PCFCs) electrolytes. The addition of sintering additives, the most widely used approach, has been found to potentially compromise electrical performance while improving sinterability in traditional sintering. Recently, SrSn 0.8 Sc 0.2 O 3- δ (SSS) has emerged as a promising proton-conductor material; however, there is still space for improvement in its electrical and sintering properties. In this study, a systematic investigation was conducted into the effect of sintering additives (NiO, ZnO, CuO) on the electrical performance of the new proton conductor SSS. Notably, SSS-1wt%NiO was found to decrease the sintering temperature from 1600 °C to 1400 °C (reaching 92 % relative density) and increase protonic conductivity from 2.61 × 10 −3 S cm −1 to 3.06 × 10 −3 S cm −1 at 600 °C, without any increase in electronic conductivity. This demonstrates a synergistic beneficial effect on both sinterability and electrical properties. Furthermore, the Ni-SSS|SSS-1wt%NiO|SSS-BCFZY single cell achieved the highest peak power density (528.5 mW cm −2 at 800 °C), surpassing all the other SSS-based single cells. Therefore, the addition of NiO to the SSS electrolyte demonstrates the significant sintering and electrical properties of SSS, proving evidence for the potential commercial application of SSS electrolytes for PCFCs.
研究领域:
材料科学
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燃料电池研究
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2017
·
IF 3.454
Mingyu Xiang,Jingjing Xie,Wei Ji,Hang Ping,Weimin Wang,Hao Wang,Jinyong Zhan,Yan Xiong,Zhengyi Fu
Zirconium carbide (ZrC 0.84 O 0.13 ) nanopowders were consolidated using plasma activated sintering with 0–8 wt% ZrH 2 as the sintering additive to improve the sinterability. Compared with pure ZrC sintering, ZrH 2 additive led to the higher sintering kinetics and lower sintering temperature . This improvement was attributed to the increased carbon-vacancy concentration in the non-stoichiometric ZrC in the presence of ZrH 2 additive during the sintering process. Fully dense and fine-grained ZrC ceramics (1.3 ± 0.2 μm) were achieved at 1650 °C with 6 wt.% ZrH 2 . The final product exhibited the Vicker’s hardness of 21.2 ± 1.0 GPa and fracture toughness of 2.2 ± 0.3 MPa m 1/2 .
研究领域:
材料科学
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陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTRONIC MATERIALS
·
2020
·Vol. 49
·期 4
·2608-2616
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IF 1.774
Chen Gang,Ji Cong,Fan Tao,Li Jiahua,Fu Chunlin,Cai Wei,Gao Rongli,Wang Zhenhua,Deng Xiaoling,Fan Peigeng
The (1 − x ) Bi (Fe 0.9 Al 0.05 Yb 0.05 ) O 3 – x BaTiO 3 (BFAYO- x BTO) ceramics were synthesized by microwave sintering (MWS) and conventional sintering (CS) methods. The crystal structure, surface morphology, dielectric and ferroelectric properties were investigated. XRD patterns show that BTO tetragonal and BFO rhombohedral phases coexist in both MWS and CS samples, and that the diffraction peaks of MWS samples shift to lower angles due to the larger ionic radius of Ba 2+ compared with Bi 3+ . The lattice constant of BFAYO- x BTO ceramics increases with the increase of BTO content. It was found that the average grain size of the MWS ceramic is much smaller than that of the CS ceramic. Dielectric measurements reveal that the dielectric loss and dielectric constant increase with BTO content increasing. The introduction of BTO into BFAYO-based ceramic contribute to the enhancement of the dielectric relaxation behavior. The P – E hysteresis loops demonstrate that the remnant polarization ( P r ) and the coercive field ( E C ) of the MWS samples are smaller than those of the CS samples. P r and E C first increase, then decrease and then increase again with the increase of BTO content. The maximum and minimum values of the remnant polarization were obtained at x = 0.25 and 0.3, respectively.
研究领域:
材料科学
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电子工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·
IF 4.527
Yuansong Luo,Han Gao,Xiujian Zhao
The NASICON-type Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 (LATP) is considered to be one of the most promising solid electrolytes because of its excellent chemical stability against moisture and considerable total ionic conductivity . Nevertheless, the poor sinterability and low grain boundary ionic conductivity of LATP limit its practical commercial applications. Herein, Li 2 CO 3 ·Bi 2 O 3 (abbreviated as LB), as a sintering aid, was introduced into LATP to improve its sinterability and ionic conductivity. It was demonstrated that the addition of LB promoted the liquid phase sintering of LATP by forming the secondary phases with a low melting point, thereby promoting the growth of grains and making the contact between the grains closer. With the help of LB, the sintering temperature of LATP was reduced to about 900 °C. A series of comparative investigations indicated that the LATP-2LB ceramic pellets sintered at 900 °C exhibited the highest total ionic conductivity of 0.673 mS/cm. Meanwhile, the relative density and grain boundary ionic conductivity of LATP-2LB ceramic pellets sintered at 900 °C reached 95.28% and 3.835 mS/cm, respectively, which is much higher than 77.16% and 0.264 mS/cm of LATP-0LB ceramic pellets sintered at the same temperature. Obviously, LB can effectively improve the sinterability of LATP while increasing its ionic conductivity, providing a new strategy for preparing LATP ceramics with excellent properties.
研究领域:
材料科学
·
电化学
·
固体化学
✓ 已验证
DOI
高影响因子
REFRACTORIES AND INDUSTRIAL CERAMICS
·
2023
·
IF 0.5
Ding Donghai,Guan Yue,Xiao Guoqing,Mao Zhaoyuan,Shi Xiaoqi,Gao Kaiqiang,Chong Xiaochuan,Luo Jiyuan,Lei Changkun
The alumina ceramics with high compressive strength were prepared by pressureless sintering, and the kaolinite and calcium carbonate were added as Al 2 O 3 –SiO 2 –CaO sintering aids. The effects of sintering temperature on the volume shrinkage, bulk density, water absorption and compressive strength of the alumina ceramics were studied. The phase composition, crystal cell parameters, average grain size and microstructure of the ceramic were analyzed by XRD, SEM and EDS. The results show that the lattice tends to packed with the increase of sintering temperature. The bonding between grains is the most compact after sintering at 1700°C. The volume shrinkage increases with the increase of sintering temperature. The water absorption of alumina ceramics after sintering at 1700°C reaches the minimum value of 0.06%. The bulk density and compressive strength increase first and then decrease with the increase of sintering temperature. At 1700°C, optimized mechanical properties of alumina ceramics is obtained, with a bulk density of 3.80 g/cm 3 and a compressive strength of 1323 MPa.
研究领域:
材料科学
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陶瓷工程
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2018
·Vol. 6
·期 24
·6406-6415
·
IF 5.976
Yue Dong,Zhijie Lin,Xiaodong Li,Qi Zhu,Ji-Guang Li,Xudong Sun
Conductive copper patterns are usually heated in vacuum, inert gas or reducing atmosphere to avoid the oxidation of copper for printed electronics applications. Here, we report a formulation of metal organic decomposition copper ink and obtained conductive copper films by heating the ink in air at low temperatures using diamine as the complexing agent without other additions. The complexing of diamine with the copper formate tetrahydrate precursor lowers the thermal decomposition temperature of the ink, promotes the densification of the film and prevents the oxidation of copper by consuming absorbed oxygen during the heating process. The copper films using 1,2-diaminopropane as the complexing agent showed a low resistivity of 1.8 × 10−5 Ω cm after heating at 180 °C for 1 min in air. The pen-writing copper patterns showed a metal copper luster and great adhesion on a PI substrate.
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
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Yang Liu,Jin-Hao Yuan,Hou-Liang Tian,Wei-Ming Guo,Shi-Kuan Sun,Xiao-Ming Duan,De-Chang Jia,Hua-Tay Lin
Spark plasma sintered SiC-based ceramics with amorphous Y 2 O 3 –Al 2 O 3 –SiO 2 and CaO–Al 2 O 3 sintering additives prepared by melt-quench approach, were compared with those with the direct addition of raw Y 2 O 3 –Al 2 O 3 –SiO 2 and CaO–Al 2 O 3 mixture. The relative densities of SiC-based with raw Y 2 O 3 –Al 2 O 3 –SiO 2 and CaO–Al 2 O 3 were 95.3% and 94.3%, respectively. In spite of the same composition of sintering additive, the relative densities of SiC-based ceramics reached the values of 98.9% and 99.5% by using the glassy additives of Y 2 O 3 –Al 2 O 3 –SiO 2 and CaO–Al 2 O 3 , respectively, and the hardness of SiC-based ceramics was improved by about 22.2% and 17.2%, respectively. The amorphous sintering additive effectively improved the densification and hardness of SiC ceramics.
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
Qi Song,Zhao-Hui Zhang,Zheng-Yang Hu,Shi-Pan Yin,Hao Wang,Zhen-Wu Ma
B 4 C ceramics were fabricated by spark plasma sintering with 5% (Ti 3 SiC 2 +Si) as sintering aid. The effects of sintering temperatures and sintering aid on microstructures and properties of B 4 C ceramics were investigated. The results indicated that the addition of a small amount of (Ti 3 SiC 2 +Si) could effectively improve the sintering characteristic of B 4 C ceramics and reduce the sintering temperature. The as-sintered ceramics fabricated at 1700 °C exhibited excellent mechanical properties , including a super-high Vickers hardness of 38.4 GPa, a high flexural strength of 457.6 MPa and a good fracture toughness of 5.61 MPa m 0.5 . Following reasons may be responsible for the improvement of the hardness of B 4 C ceramics: high relative density due to the combination use of (Ti 3 SiC 2 +Si) sintering aids and SPS technology, fine-grained structure of the B 4 C ceramics benefited from the low sintering temperature, formation of the second phases TiB 2 and SiC by chemical reaction and existence of the nano-sized unit of (TiB 2 +SiC) in B 4 C grains.
研究领域:
材料科学
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陶瓷工程
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Linkai Ren,Quanxing Ren,Ziqiang Yin,Tihao Cao,Xuxin Ping,Fangfang Ge,Zhengren Huang,Qing Huang,Yinsheng Li
In order to achieve low-temperature densification of SiC ceramic, β-SiC nanopowder was doped with Li 2 O together with Y 2 O 3 –Al 2 O 3 –MgO as sintering aids, and then spark plasma sintered at temperatures ranging from 1450 °C to 1600 °C for 30 min under 30 MPa pressure in argon. The densities, microstructures and mechanical properties of SiC ceramics were systematically investigated, in comparison to the counterparts sintered with Y 2 O 3 –Al 2 O 3 –MgO additives. Since Li 2 O has a low melting point, Li 2 O addition effectively decreased the formation temperature of liquid secondary phase, enabling SiC ceramics to obtain higher density and lower porosity after low-temperature sintering (T ≤ 1550 °C). Besides, Li 2 O addition was found to decrease the viscosity of liquid phase and enhance grain growth of SiC through dissolution-reprecipitation process. When sintered at 1550 °C, Li 2 O addition led to a remarkable increase of density from 3.03 g/cm 3 to 3.21 g/cm 3 for SiC ceramic. Meanwhile, the SiC ceramic with Li 2 O addition exhibited a high Vickers hardness of 22.75 ± 0.35 GPa and a good fracture toughness of 3.83 ± 0.27 MPa m 1/2 . The research results are expected to benefit the low-cost fabrication of SiC ceramics based on pressure-assisted sintering and alleviate the thermal damage of SiC fiber in hot-pressed SiC f /SiC composites.
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
危险品化学品经营许可证（带存储）