JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2013
·Vol. 24
·期 12
·4913-4918
·
IF 1.486
Wu Min,Lin Baoping,Cao Yi,Song Jiangang,Sun Ying,Yang Hong,Zhang Xueqin
In this paper, uniform and well dispersed silver-coated copper powders were prepared by replacing reaction at first. The structure and properties of the bimetallic powders were investigated by XRD, SEM and TGA. It was found that anti-oxidization of the silver-coated copper powders increased with the increase of the silver content slightly and a dense coating surface was observed at Ag content of 53.9 wt%. Furthermore, the pastes with relatively low silver content which were prepared from silver-coated copper powders, displayed high conductivity similar to pure silver even after sintering in air. And their sintering properties were also investigated at different temperature in air atmosphere. The film exhibits good electrical properties at sintering temperature between 800 and 900 °C. When the paste from silver-coated copper powder with Ag content of 53.9 wt% was printed on Al 2 O 3 substrate and sintered at 800 °C in air, the sheet resistance of the film is 0.036 Ω/□ only.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
NANOTECHNOLOGY
·
2019
·Vol. 30
·期 35
·355601
·
IF 3.399
Xinyan Hu,Gang Li,Pengli Zhu,Jiaoning Tang,Rong Sun,Ching-Ping Wong
The inherent susceptibility to oxidation and poor sinterability significantly limit the practical application of Cu-based conductive inks. Most methodologies employed for the inks like organic polymer coatings and inorganic metal deposition are generally ineffective. Herein, we report the design of a novel hierarchical Cu architecture to simultaneously improve the antioxidative and sinterability via a self-passivation mechanism and loose interior structures. The hierarchical Cu architecture was prepared using copper hydroxide, L-ascorbic acid, and polyvinylpyrrolidone in aqueous solution; 40 g Cu were prepared in a scale-up experiment. A possible growth mechanism is proposed, involving the Cu2O-templated and mediated nucleation and growth of Cu nanocrystals, followed by the PVP-directed electrostatic self-assembly of Cu nanocrystals. The synthesized Cu shows high oxidation resistance after stored in ambient environment for 90 d by self-passivation, wherein the dense oxidized external layer prevented further oxidation of Cu, unlike other antioxidative strategies. In addition, the structure became 2D flake after a simple ball-milling for 10 min of 2000r, thus forming a good conductive network at the temperature of 180 °C. Importantly, no obvious decline in the electrical performance after severe surface oxidation. Although the structure cannot offer excellent conductive performance, but it proposes a new solution for the balance of antioxidative capabilities and good sinterability in Cu nanomaterials, thus facilitating greater utilization of Cu-based conductive inks for emerging flexible electronic applications.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2020
·
IF 3.408
Ruiqi Ma,Jiahui Shi,Wenxin Lin,Jianjun Chen
This paper reports a simple route to synthesize nanocrystalline silicon carbide (SiC) ceramic powders via the direct reaction of silicon powders with carbon black in a temperature-programmed muffle furnace. The mixing powders of silicon and carbon black were loaded in a alumina crucible, and then the crucible was sealed with some materials to prevent oxidization. The effect of reaction temperature on the phase of the product powders was investigated. FESEM and TEM images showed that the SiC nanopowders were spherical and had an average particle size of 48.56 nm. The sintering activities of the SiC nanopowders and commercial SiC fine powders were also investigated by hot-pressing sintering. SiC nanoceramic sintered at 1850 °C exhibited a high relative density (up to 99.2%) and a high flexural strength of 580 MPa, which exhibits better sintering activity of synthesized SiC nanopowders.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2020
·
IF 3.408
Jiawei Wei,Bingqiang Han,Xuancheng Wang,Junfeng Chen,Yaowu Wei,Wen Yan,Nan Li
In this paper, CaO granules were prepared, using the slaked lime as the raw material as well as ZrO 2 , TiO 2 , and V 2 O 5 as additives, respectively. The influence of different additives on the sintering properties, microstructure and hydration resistance of CaO granules was investigated. The results indicated that the introduction of additives could obviously promote the densification and the hydration resistance of the specimens. Especially, the sintering mechanisms of the specimens with different additives were studied. For the specimens with ZrO 2 and TiO 2 as additives, the in-situ formed CaZrO 3 and Ca 3 Ti 2 O 7 between grain boundaries promoted the densification to enhance the properties of the granules. However, the adding of V 2 O 5 generated a coating on the surfaces of CaO granules which contributed to the best hydration resistance.
研究领域:
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Guannan Yang,Pengyu Wang,Yu Liu,Shuzhou Lu,Bo Luo,Tao Lai,Shiwo Ta,Tingyu Lin,Jiye Luo,Yu Zhang,Chengqiang Cui
Ag-coated Cu particles (Cu@Ag particles) are highly anticipated bimetallic materials with wide electronic applications. However, it is still crucially challenging to obtain well-covered Ag shells and facilitate the synthetic process, and the sintering/migration behaviors of Cu@Ag particles are also poorly understood. In this study, we develop a facile Ag coating method for Cu@Ag particles with the assistance of double complexing agents. Electrochemical analysis reveals that the complexing effect can effectively reduce the potential difference of the Cu-Ag replacement reaction, and thereby improve the coating quality. Cu@Ag particles with compact and uniform Ag shells are obtained, with Ag contents as low as ~10 at%. The as-prepared Cu@Ag particles show significantly improved oxidation resistance and reliable sintering property. Moreover, the Cu@Ag particles exhibit superior ion migration resistance even better than both Cu and Ag particles under an oxygen-containing environment. The results could provide helpful basis for understanding the synthesis, sintering and migration processes of Cu@Ag particles. The comprehensive performance of Cu@Ag particles makes them a promising interconnected material in future electronic industry.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
Materials Research Express
·
2019
·Vol. 6
·期 12
·126586
·
IF 1.449
Zhuangzhi Wu,Xin Liu,Dezhi Wang
A traditional preparation process of Mo powder is generally time-consuming and leads to coarse particles. In this work, we propose a short-flow strategy, in which the intermediate product of MoO2 is prepared by a one-step self-reduction method in air instead of a mixture of decomposition and hydrogen reduction processes. And the reaction mechanism of self-reduction is investigated and the consequent sintering performance of Mo powder is also compared with the traditional one. The obtained results demonstrate that the finally synthesized Mo–La2O3 powder prepared by the self-reduction strategy are spherical with an average particle size of 2.03 μm, exhibiting an excellent sintering performance with a relative density of 95.3% and a hardness of 260.6 (HV), better than those by a traditional one (93.4% and 232.4 (HV)), which can be attributed to smaller particle size and better shapes. This work provides a new route for the synthesis of Mo–La2O3 powder, indicating a possible industrial application.
研究领域:
材料科学
·
冶金工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2015
·
IF 2.947
Xiaowei Chi,Zhaoyin Wen,Jingchao Zhang,Yu Liu
A novel hybrid route, combining simple co-precipitation and conventional solid state reaction, is proposed for the first time to synthesize BaCe 0.4 Zr 0.4 Y 0.2 O 3− δ powders at a temperature as low as 1150 °C. This temperature is much lower than that used for conventional solid state reaction method and even comparable to that used in sol–gel route. The reasons for the low calcination temperature are analyzed in detail from the macroscopic to microscopic viewpoints. Moreover, with the powders made by the novel method, dense ceramic could be easily obtained. Further, impedance data illustrated that its electrical conductivity in wet H 2 at 750 °C is up to 1.39 × 10 −2 S/cm, which is the highest among all the samples prepared by the three different methods and much higher than the reported results related to BCZY proton conductors . Also, the new method is particularly suitable for other multi-component oxides .
研究领域:
材料科学
·
无机化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2021
·
IF 5.816
Wenjie Yang,Chao Han,Yuehua Li,Huizhu Zhou,Shan Liu,Ling Wang,Zhangxing He,Lei Dai
BaHf 0.8 Ln 0.2 O 3-δ doped with rare earth elements with different ionic radii (Ln = Yb , Y, Dy and Gd) as candidate materials for solid oxide fuel cells and H 2 separation membrane have been prepared. Their phase composition , sinterability , chemical stability and conductivity were studied systematically. The rare earth elements are successfully incorporated into the main phase crystal lattice of barium hafnate to generate a single perovskite phase. The relative density of all samples sintered at 1600 °C reaches above 90%, and Y-doped BaHfO 3 has the highest relative density (94.7%) and the biggest grain size (about 1 μm) among all samples. The conductivities of the samples firstly increase and then decrease with the increase of the doped ion radius. Among all samples the conductivity of BaHf 0.8 Y 0.2 O 3-δ is the highest and reaches 6.02 × 10 −3 S cm −1 in wet air at 700 °C, which is attributed to the good sinterability and suitable crystal structure (tolerance factor and free volume). All samples also show excellent chemical stability in the test atmospheres, including saturated H 2 O steam, pure H 2 and CO 2 , 200 ppm H 2 S/Ar and boiling water. The Pt/BaHf 0.8 Y 0.2 O 3-δ electrolyte/Pt single cell was fabricated with a 530 μm-thick disk and its electrochemical properties were tested. The peak power density reaches 10.21 mW cm −2 at 700 °C, which is comparable to similar fuel cells reported. These results suggest that BaHf 0.8 Y 0.2 O 3-δ is a promising electrolyte candidate for proton-conducting fuel cells.
研究领域:
材料科学
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能源工程
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2023
·Vol. 21
·期 1
·51-61
·
IF 2.1
Xiong Gao,Deng Zhang,Xueru Feng,Jiamin Zhang,Yuqing Peng,Zhicheng Pan,Zongming Dai
The aim of this work is to prepare interlocking prismatic mullite from low-cost associated rare-earth kaolin. High-performance mullite was synthesized by reaction sintering using calcined associated rare-earth kaolin and α-Al 2 O 3 as raw materials and micro- and nano-La 2 O 3 as additives. The mineralogical, morphological, and chemical characteristics of calcined associated rare earth kaolin were analyzed, and the effects of the addition of micro- and nano-La 2 O 3 and sintering temperature on the phase transformation, sintering process, microstructure, and mechanical properties of mullite were studied. The results show that the associated rare earth elements Ce, Th, and Y in calcined kaolin are mainly light rare earth elements, which are mainly endowed in the interlayer structure of K-bearing clay minerals. The addition of La 2 O 3 can promote the growth of secondary mullite grains and accelerate the secondary mullitization process. The relative densities of mullite samples adding 4 wt.% micro/nano La 2 O 3 and sintered at 1500°C for 4 h were 92.72% and 93.4%, and the micro Vickers hardnesses were 11.32 and 12.35 GPa, respectively. The mullite sample with 2 wt.% nano-La 2 O 3 had the most interlaced prismatic grains, resulting in the highest flexural strength of 157.8 MPa.
研究领域:
材料科学
·
陶瓷学
✓ 已验证
产品关联
DOI
高影响因子
Virtual and Physical Prototyping
·
2025
·
IF 8.8
Yongkang Yang,Xiqing Xu,Boran Wang,Shiyuan Li,Ziqi Jia,Xusen Guo,Shuhuai Wang,Shuxin Niu,Xin Li
Vat photopolymerization (VPP) 3D printing technology is suited for intricate ceramic core forming due to its design freedom. However, solving the lateral over-cure width while formation is crucial. Graphene was used in VPP-3D printing of silica-based ceramic cores to examine its effects on forming and sintering, and a desirable curing coefficient was presented to evaluate the forming accuracy of single layer. A straightforward model using a modified Beer–Lambert law based on exposure time rather than exposure power predicts the effect of graphene on the VPP process at consistent curing depth and exposure time and clarifies how the curing process affects flexural strength and surface quality. The optimal graphene content was determined by double bond conversion rate, structural anisotropy, and mechanical properties. Increasing graphene concentration reduces curing sensitivity and exposure time threshold, allowing more liquid phase to cure and improving double bond conversion and interlayer bonding. However, excess graphene increases the conversion rate and stress concentration of green body. According to microstructural studies, extra graphene enhanced the likelihood of crack reformation after sintering. The ceramic cores had optimal forming and sintering capabilities with 0.6 wt.‰ graphene content. The approach offers significant insights for enhancing VPP ceramic 3D printing.
研究领域:
材料科学
·
增材制造
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2022
·Vol. 106
·期 2
·444-454
·
IF 2.606
Zhang Ji,Mu Chengfa,Shen Tao,Qi Gengxin
Different micro-structured SnO 2 powders were synthesized by hydrothermal and chemical co-precipitation methods. The influence of milling process and sintering parameters on the physical properties of Ag/SnO 2 electrical contact materials was investigated. The microstructure and physical properties of Ag/SnO 2 electrical contact materials were characterized by X-ray Diffraction, Scanning Electron Microscopy and Conductivity analyzer. The results showed that spherical SnO 2 (s) powders with a diameter about 2 μm were synthesized. With increased milling time, there was a slight decrease in the average sizes of Ag/SnO 2 (s) powders, but no significant difference. The optimal density of 9.545 g∙cm −3 and resistivity of 2.67 μΩ∙cm of Ag/SnO 2 (s) electrical contact materials were obtained after sintering at 860 °C for 6 h in air atmosphere. The promotion of sintering densification and improvement of physical properties of Ag/SnO 2 (s) contact may be due to the combined effects of mechanical activation energy and higher sintering temperature. Using the finite element method, simulation models were developed to interpret the effects of different micro-structured SnO 2 powders on the physical properties of Ag/SnO 2 materials.
Graphical abstract
研究领域:
材料科学
·
电气工程
✓ 已验证
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2021
·
IF 5.039
Yuxiao Xue,Jian Pan,Deqing Zhu,Zhengqi Guo,Hongyu Tian,Yue Shi,Shenghu Lu
Iron ores always contain several forms of alumina, which may have different effect on sintering performance. In this paper, sinter pot tests were systematically conducted with various alumina types and contents by means of alumina additives substituting for the corresponding types of alumina, and the relevant action mechanism on sintering performance was clarified by the mineralogy of product sinter. The results show that kaolinite is beneficial to the granulation process rather than other three alumina types. In addition, it contributes to relatively better sintering performance while aluminous goethite ranks the only next, followed by gibbsite and free alumina. Mechanism analysis indicates that kaolinite and aluminous goethite are preferable to achieve relatively lower sinter porosity and higher amount of silico-ferrite of calcium and alumina (SFCA) compared with gibbsite and free alumina. Besides, the former two alumina types are apt to promote the formation of higher strength SFCA such as dendritic and acicular SFCA. Furthermore, much tighter interlocking texture in product sinter is formed as alumina occurs in kaolinite or aluminous goethite. Kaolinite and aluminous goethite are the preferably desirable alumina types for sintering rather than free alumina and gibbsite.
研究领域:
冶金工程
·
材料科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）