25 results on '"Haibo Tang"'
Search Results
2. Study on Optimization of Nozzle Angle for Oxygen-Rich Side-Blown Lead Melting Furnace
- Author
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Zhiwei Jiang, Xu Wang, Qingwei Qin, Zhengming Yi, Rongsheng Chen, and Haibo Tang
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Metals and Alloys ,oxygen-rich side-blowing furnace ,multiphase flow simulation ,inclination angle of spray gun ,structure optimization ,General Materials Science - Abstract
Taking an oxygen-rich side-blown lead melting furnace made by a company as the research object, the three-dimensional design software Solidworks was used to construct a model at an equal scale, and established a physical model which is in line with the actual system. Based on the determination of the physical properties of the slag phase and metal phase in the furnace, the VOF multiphase flow model and standard turbulence model in FLUENT were used to simulate the gas–liquid multiphase flow. By adjusting the different inclination angles of the spray gun, we analyzed the distribution changes of key indicators, such as the flow field, average turbulent kinetic energy and gas content in the furnace. At the same time, it was found that the turbulent kinetic energy in the middle of the furnace was large, which could strengthen the winding effect of the material and the best arrangement. The gas content of the upper part of the oxygen gun was high, and the gas content in the middle of the furnace was higher than that in the wall area on both sides and showed a gradual downward trend. If the inclination angle of the spray gun is too small, the agitation of the lower melting area is not strong enough, On the contrary, if the inclination angle is too large, the local flow rate of the sedimentation area increases and the gas content is low. The optimal tilt angle of the spray gun is between 10° and 15°.
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- 2023
- Full Text
- View/download PDF
3. Probing heat generation and release in a 57.5 A h high-energy-density Li-ion pouch cell with a nickel-rich cathode and SiOx/graphite anode
- Author
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Xiaopeng Qi, Bingxue Liu, Fengling Yun, Changhong Wang, Rennian Wang, Jing Pang, Haibo Tang, Wei Quan, Qiang Zhang, Man Yang, Shuaijin Wu, Jiantao Wang, and Xueliang Sun
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Renewable Energy, Sustainability and the Environment ,General Materials Science ,General Chemistry - Abstract
This study clarifies the heat generation and release of a 57.5 Ah HED (266.9 W h kg−1) Li-ion cell with a nickel-rich cathode and SiOx/graphite anode. Significant heat accumulation and delayed heat release effects in large-format cells are uncovered.
- Published
- 2022
4. N coupling with S-coordinated Ru nanoclusters for highly efficient hydrogen evolution in alkaline media
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Haibo Tang, Ling-Jie Xie, Cheng-Fei Li, Yu Wang, Jia-Wei Zhao, Gao-Ren Li, and Lirong Zheng
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Materials science ,Renewable Energy, Sustainability and the Environment ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,Overpotential ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Photochemistry ,Persulfate ,01 natural sciences ,0104 chemical sciences ,Nanoclusters ,Ruthenium ,Catalysis ,Metal ,X-ray photoelectron spectroscopy ,chemistry ,visual_art ,visual_art.visual_art_medium ,General Materials Science ,0210 nano-technology ,Spectroscopy - Abstract
Optimizing the coordination/surrounding environments of active metal nanoclusters to promote the catalytic performance during hydrogen evolution reaction (HER) in alkaline media is highly important but extremely challenging. Here, we demonstrate that novel S-coordinated ruthenium (Ru) nanoclusters anchored on N/S-codoped carbon nanosheets (Ru–S/N–C) can be successfully synthesized via the space-confinement pyrolysis of Ru complexes in the framework of polyaniline–ammonia persulfate supermolecules. X-ray absorption fine structure spectroscopy and X-ray photoelectron spectroscopy studies reveal the local coordination structure of Ru–S bonds, the surrounding N/S/C environments of Ru, and the synergistic electronic interactions among N, S, C and Ru atoms. Theoretical calculations further confirm that the coordination/surrounding environments could optimize the adsorption energies of intermediates on Ru through interfacial charge transfer and, thus, accelerate the reaction kinetics of hydrogen evolution. The fabricated Ru–S/N–C exhibits an ultra-small overpotential of 10 mV at 10 mA cm−2 and an extremely high turnover frequency (TOF) of 2.3 H2 s−1 at an overpotential of 50 mV for the HER, as well as a mass catalytic activity about 10 times higher than that of a commercial Pt/C catalyst.
- Published
- 2021
5. Non-isothermal β grain growth behaviour of pure titanium under laser quenching
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Zhuo Li, Huaming Wang, Xu Cheng, Jing Li, Haibo Tang, and Xiao Zong
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010302 applied physics ,Laser quenching ,Materials science ,Mechanical Engineering ,chemistry.chemical_element ,Titanium alloy ,Crystal growth ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Isothermal process ,Grain growth ,chemistry ,Chemical engineering ,Mechanics of Materials ,0103 physical sciences ,General Materials Science ,0210 nano-technology ,Laser processing ,Titanium - Abstract
The primary understanding of laser-induced non-isothermal prior β grain growth behaviour of titanium alloys is given by adopting laser quenching on pure titanium. Results indicate that the prior β ...
- Published
- 2020
6. Mesoporous carbon confined intermetallic nanoparticles as highly durable electrocatalysts for the oxygen reduction reaction
- Author
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Haibo Tang, Zhiming Cui, Wen-Jie Jiang, Jin-Song Hu, Weiyue Zhao, Li Du, Shijun Liao, Yuekun Ye, and Jing Li
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Materials science ,Renewable Energy, Sustainability and the Environment ,Alloy ,Intermetallic ,Proton exchange membrane fuel cell ,Nanoparticle ,02 engineering and technology ,General Chemistry ,engineering.material ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,Electrocatalyst ,01 natural sciences ,Durability ,0104 chemical sciences ,Catalysis ,Chemical engineering ,engineering ,General Materials Science ,0210 nano-technology - Abstract
Exploring advanced electrocatalysts for the sluggish oxygen reduction reaction is extremely important for fuel cell commercialization but still remains a great challenge, especially the durability issue that gains increasing attention. Herein, we demonstrate an extremely durable catalyst prototype that combines structurally ordered intermetallic nanoparticles (NPs) with mesoporous carbon. With ZIF-8 derived mesoporous carbon supported Pt3Co intermetallic NPs (Pt3Co/DMC-F) as an example, we illustrate its synthetic details, electrocatalytic performance and durability enhancement mechanism. The Pt3Co/DMC-F catalyst exhibited significant enhancement in activity and durability. More importantly, its extraordinary performance was observed/verified in a H2/air PEM single cell test. The confinement of mesoporous carbon not only efficiently controls the particle size of Pt3Co and hampers their aggregation during thermal annealing and electrochemical reactions, but also significantly suppresses detachment. Beyond offering an advanced electrocatalyst, this study provides a solution to the durability issue of cathodes that has prevented practical application of proton exchange membrane fuel cells.
- Published
- 2020
7. Origin of aspect ratio decreasing and variant selection for alpha laths in laser directed energy deposited TC11-xB alloys: Spatial inhibition and selective coarsening in thermal cycle
- Author
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Junwei Yang, Haibo Tang, Renkai Li, Zhuo Li, Fang Cheng, Yansong Zhang, and Yanyan Zhu
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History ,Polymers and Plastics ,Mechanics of Materials ,Mechanical Engineering ,General Materials Science ,Business and International Management ,Condensed Matter Physics ,Industrial and Manufacturing Engineering - Published
- 2022
8. Additive manufactured Mg-Gd-Y-Zr alloys: Effects of Gd content on microstructure evolution and mechanical properties
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Yiling Jiang, Haibo Tang, Zhuo Li, Dongdong Zheng, and Yuxuan Tu
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Biomedical Engineering ,General Materials Science ,Engineering (miscellaneous) ,Industrial and Manufacturing Engineering - Published
- 2022
9. Effect of multiple thermal cycles on the microstructure evolution of GA151K alloy fabricated by laser-directed energy deposition
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Dongdong Zheng, Zhuo Li, Yiling Jiang, Renkai Li, Yujuan Wu, Yuxuan Tu, Xu Cheng, Penghuai Fu, Liming Peng, and Haibo Tang
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Biomedical Engineering ,General Materials Science ,Engineering (miscellaneous) ,Industrial and Manufacturing Engineering - Published
- 2022
10. Ice Coverage Induced by Depositing a Water Drop onto the Supercooled Substrate at Extreme Low Vapor Pressure
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Xin Zhang, Yugang Zhao, Haibo Tang, and Zichao Zuo
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Materials science ,drop impinging ,Vapor pressure ,020209 energy ,General Chemical Engineering ,anti-icing ,02 engineering and technology ,Substrate (electronics) ,Physics::Geophysics ,Inorganic Chemistry ,ice coverage ,0202 electrical engineering, electronic engineering, information engineering ,General Materials Science ,Diffusion (business) ,Supercooling ,Physics::Atmospheric and Oceanic Physics ,Icing ,Crystallography ,Accretion (meteorology) ,aircraft icing ,Drop (liquid) ,Mechanics ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,QD901-999 ,Astrophysics::Earth and Planetary Astrophysics ,0210 nano-technology ,Order of magnitude - Abstract
Icing/snowing/frosting is ubiquitous in nature and industrial processes, and the accretion of ice mostly leads to catastrophic consequences. The existing understanding of icing is still limited, particularly for aircraft icing, where direct observation of the freezing dynamics is inaccessible. In this work, we investigate experimentally the impact and freezing of a water drop onto the supercooled substrate at extremely low vapor pressure, to mimic an aircraft passing through clouds at a relatively high altitude, engendering icing upon collisions with pendant drops. Special attention is focused on the ice coverage induced by an impinging drop, from the perimeter pointing outward along the radial direction. We observed two freezing regimes: (I) spread-recoil-freeze at the substrate temperature of Ts = −15.4 ± 0.2 °C and (II) spread (incomplete)-freeze at the substrate temperature of Ts = −22.1 ± 0.2 °C. The ice coverage is approximately one order of magnitude larger than the frozen drop itself, and counterintuitively, larger supercooling yields smaller ice coverage in the range of interest. We attribute the variation of ice coverage to the kinetics of vapor diffusion in the two regimes. This fundamental understanding benefits the design of new anti-icing technologies for aircraft.
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- 2021
- Full Text
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11. Transition Metal Nitrides for Electrocatalytic Application: Progress and Rational Design
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Zihan Meng, Shuhong Zheng, Ren Luo, Haibo Tang, Rui Wang, Ruiming Zhang, Tian Tian, and Haolin Tang
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General Chemical Engineering ,General Materials Science - Abstract
The energy crisis and environmental issues are becoming more severe due to the long-term consumption of fossil fuels. Therefore, novel energy-conversion devices with high energy density and environmental friendliness are expected to provide reliable alternatives to traditional fossil-based energy systems. However, because of the inevitable use of costly precious metals as the electrode catalysts for such devices, their popularization is seriously hindered. Transition metal nitrides (TMNs) exhibit similar surface and adsorption properties to noble metals because the atomic distance between metal atoms increases and the d-band center of metal atoms downshifts after nitrogen atoms enter the metal lattice. TMNs have become one of the best electrode materials to replace noble metal-based electrocatalysts in next-generation energy-storage and energy-conversion devices. In this review, the recent developments in the electrocatalytic application of TMNs are covered. First, we discuss the structure and activity origin of TMNs and introduce the common synthesis methods for the preparation of TMNs. Subsequently, we illustrate the applications of mono-metallic TMNs and multi-metallic TMNs in oxygen-reduction reaction, oxygen-evolution reaction, and bifunctional oxygen reduction and evolution reactions. Finally, we summarize the challenges of TMNs encountered at the present stage, and expect their future development.
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- 2022
12. Microstructure characterization and evolution mechanism of titanium during laser surface nitriding
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Xiao Zong, Huaming Wang, Jing Li, Xu Cheng, Zhuo Li, and Haibo Tang
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Mechanics of Materials ,Mechanical Engineering ,General Materials Science ,Condensed Matter Physics - Published
- 2022
13. Parallel Processing of Probabilistic Models-Based Power Supply Unit Mid-Term Load Forecasting With Apache Spark
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Haibo Tang, Wei Jiang, He Huang, Lei Wu, and Hui Qi
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DBSCAN ,Apache Spark ,General Computer Science ,parallel computing ,Computer science ,020209 energy ,Real-time computing ,Dynamic bayes network ,mid-term load forecasting ,General Engineering ,Probabilistic logic ,Bayesian network ,02 engineering and technology ,Parallel processing (DSP implementation) ,Spark (mathematics) ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,General Materials Science ,lcsh:Electrical engineering. Electronics. Nuclear engineering ,Power supply unit ,Forward algorithm ,lcsh:TK1-9971 - Abstract
Mid-term load forecasting (MTLF) of power supply unit (PSU) is an essential part of refined distribution network planning. By analyzing a large amount of historical data accumulated in electric automation systems, accurate MTLF result can be obtained with the help of big-data and parallel computing technology. In this paper, a dynamic bayes network (DBN)-based MTLF model is proposed to forecast the peak power load of next year of each PSU. In the first stage, we improve the accuracy of MTLF model by using dynamic radius DBSCAN algorithm to determine the optimal state division. In the second stage, to improve the computation efficiency, the calculations of multiple probability matrixes and the modified forward algorithm are implemented on an apache spark-based parallel computing platform. The experiment results indicate that the parallel processing of DBN-based MTLF model has superior performance in accuracy, efficiency, and versatility.
- Published
- 2019
14. The spatial distribution of α phase in laser melting deposition additive manufactured Ti-10V-2Fe-3Al alloy
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Zhuo Li, Zongge Jiao, Huaming Wang, Jun Fu, Xu Cheng, and Haibo Tang
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010302 applied physics ,Materials science ,Morphology (linguistics) ,Plane (geometry) ,Mechanical Engineering ,Alloy ,02 engineering and technology ,engineering.material ,021001 nanoscience & nanotechnology ,Microstructure ,01 natural sciences ,Forging ,Mechanics of Materials ,Phase (matter) ,0103 physical sciences ,lcsh:TA401-492 ,Perpendicular ,engineering ,Deposition (phase transition) ,lcsh:Materials of engineering and construction. Mechanics of materials ,General Materials Science ,Composite material ,0210 nano-technology - Abstract
Ti-10V-2Fe-3Al alloy specimen has been fabricated by laser melting deposition additive manufacturing technique. Due to the repeated heating and cooling during deposition, complicated and unique phase transformation process take place with forming different microstructures from forging. In this study, a three-dimensional (3D) reconstruction method is used to understand the spatial distribution of α phase in different grains. The results indicated that, in as deposited alloy, α laths has a plate morphology, and they precipitated out from β phase followed a tetrahedral relationship. And the different grain orientation result to the specific different morphology. When the cutting plane parallel to the {100} plane of BCC cell, α laths are perpendicular to each other. If the cutting plane is parallel to the {111} plane, a special morphology with mixture of plate-like and rod-like α phase is founded. Keywords: Laser additive manufacturing, Ti-10V-2Fe-3Al, Titanium alloys, Spatial distribution, Phase transformation
- Published
- 2018
15. The Effect of Acid Mine Drainage Corrosion on the Creep Deformation of Cemented Gangue Backfill
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Kun Wang, Haibo Tang, and Zhaoxing Lv
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Materials science ,Article Subject ,0211 other engineering and technologies ,General Engineering ,02 engineering and technology ,010501 environmental sciences ,Acid mine drainage ,01 natural sciences ,Corrosion ,Kelvin model ,Compressive strength ,Creep ,021105 building & construction ,TA401-492 ,Gangue ,General Materials Science ,Composite material ,Elastic modulus ,Materials of engineering and construction. Mechanics of materials ,0105 earth and related environmental sciences - Abstract
Acid mine drainage (AMD) is a hazardous by-product of coal mining, which may intensify the creep deformation of cemented gangue backfill (CGB) in solid backfill mining. In this study, the long-term stability and creep property of CGB soaked in AMD were quantitatively measured by experimental and theoretical analysis. The uniaxial compressive strength, elastic modulus, and mass of CGB soaked in AMD, with pH of 5.56 and soaking time of 30 to 360 days, were tested. The change trend of compressive strength, elasticity modulus, and mass first increased, then decreased, and finally ended at 94.37%, 96.68%, and 98.00%, respectively. The respective creep processes of CGB soaked in AMD and untreated CGB were similar, initial creep stage lasted only for a short time, and no creep deformation occurred in the steady creep stage. Moreover, the long-term strength of CGB soaked in AMD was 98.6% of the untreated CGB. The creep law of the CGB soaked in AMD was accurately fitted by using the Kelvin model. The theoretical analysis revealed that the final creep deformation of the CGB column soaked in AMD was only 4.4 mm. The results of this paper show the possibility of using CGB in AMD-accumulating goaf.
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- 2020
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16. Effects of microstructures on the fatigue crack growth behavior of laser additive manufactured ultrahigh-strength AerMet100 steel
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Haibo Tang, Xu Cheng, Xian-zhe Ran, Xiao Liu, Huaming Wang, Ji-kui Zhang, Jia Li, and Dong Liu
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Austenite ,Materials science ,Bainite ,Mechanical Engineering ,02 engineering and technology ,Paris' law ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,Cracking ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Mechanics of Materials ,Martensite ,General Materials Science ,Texture (crystalline) ,Dislocation ,Composite material ,0210 nano-technology - Abstract
In order to evaluate the effects of microstructure characteristics on fatigue crack growth (FCG) resistance of laser additive manufactured (LAM) AerMet100 steel, microstructures and FCG behaviors (in Paris region) of as-deposited specimen and three types of tempered martensite specimens were examined. Results indicate as-deposited specimens of LAM AerMet100 steel have apparent texture characteristics of epitaxy unidirectional growth prior-austenite columnar grains and grain-interior inter-dendritic blocky retained austenite with [001] crystallographic orientation. And poor boundary cracking resistance of these texture characteristics along deposition direction mainly contributes to the FCG rate anisotropy of as-deposited specimens. After post-LAM heat treatments, the FCG resistance of all heat-treated specimens apparently improves with the fracture mode of transgranular cracking. With the increase of yield strength, the value of Paris coefficient C of the steel increases, but the value of Paris exponent m decreases. Compared to the poor dislocation slip resistance of bainite plates in as-deposited specimens, the improved dislocation slip resistance of martensite plates is mainly related to the strong dislocation pinning effect of fine dispersive rod-like coherent M2C carbides, resulting in the stronger FCG resistance of the heat-treated specimens. In the Paris region of low ΔK ( ~ 70 MPa m1/2), higher contents of retained/reverted austenite inversely accelerate the FCG rate of heat-treated LAM AerMet100 steel. In contrast, grain refinement has the little influence on the FCG rate (in most of Paris region) of the heat-treated specimens.
- Published
- 2018
17. Effects of post homogeneity heat treatment processes on microstructure evolution behavior and tensile mechanical properties of laser additive manufactured ultrahigh-strength AerMet100 steel
- Author
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Jia Li, Xian-zhe Ran, Xu Cheng, Bei He, Xiao Liu, Dong Liu, Haibo Tang, and Huaming Wang
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010302 applied physics ,Austenite ,Equiaxed crystals ,Materials science ,Mechanical Engineering ,Alloy ,02 engineering and technology ,engineering.material ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,01 natural sciences ,Carbide ,law.invention ,Optical microscope ,Mechanics of Materials ,law ,Martensite ,0103 physical sciences ,Ultimate tensile strength ,engineering ,General Materials Science ,Composite material ,0210 nano-technology - Abstract
Ultrahigh-strength AerMet100 steel plate was fabricated by laser additive manufacturing process (LAM) followed by subsequent heat treatments. Microstructures and tensile mechanical properties of the steel were examined using optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and universal mechanical testing machine. The results indicate that post-LAM heat treatments greatly change alloy carbide characteristics, decrease austenite content and prompt the formation of fine equiaxed prior-austenite grains for LAM AerMet100 steel. Compared to fine short rod-like Nb-rich MC carbides and needle-like M3C carbides in as-deposited specimens, alloy carbides in tempered specimens have the large changes, which include fine spherical Nb-rich MC carbides, fine rod-like M2C carbides, large-size spherical Mo-rich M6C carbides and Cr-rich M23C6 carbides. And the fine rod-like M2C carbides are dispersive distribution and coherency with the martix martensite, resulting in strong coherent strain strengthening. After proper post homogeneity heat treatment processes, tensile mechanical properties of LAM AerMet100 steel have the comprehensive improvement, which are comparable to those of the forged ones. In comparison with low ductility of as-deposited specimen, the higher ductility of tempered specimen is mainly related to its extremely strong strain-strengthening capability achieved by dispersive precipitation of M2C carbides. With the increase of homogenization, the further improved ductility of tempered specimen mainly ascribe to the decreased amount and size of large-size alloy carbides (especially Mo-rich M6C carbide).
- Published
- 2018
18. Highly Selective TiN-Supported Highly Dispersed Pt Catalyst: Ultra Active toward Hydrogen Oxidation and Inactive toward Oxygen Reduction
- Author
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Sanying Hou, Shijun Liao, Haibo Tang, Junming Luo, Li Du, Xiuhua Li, and Xinlong Tian
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chemistry.chemical_classification ,Materials science ,chemistry.chemical_element ,02 engineering and technology ,Electrolyte ,Polymer ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Catalysis ,Anode ,chemistry ,Chemical engineering ,General Materials Science ,0210 nano-technology ,Tin ,Platinum ,Selectivity ,Dissolution - Abstract
The severe dissolution of the cathode catalyst, caused by an undesired oxygen reduction reaction at the anode during startup and shutdown, is a fatal challenge to practical applications of polymer electrolyte membrane fuel cells. To address this important issue, according to the distinct structure-sensitivity between the σ-type bond in H2 and the π-type bond in O2, we design a HD-Pt/TiN material by highly dispersing Pt on the TiN surface to inhibit the unwanted oxygen reduction reaction. The highly dispersed Pt/TiN catalyst exhibits excellent selectivity toward hydrogen oxidation and oxygen reduction reactions. With a Pt loading of 0.88 wt %, our catalyst shows excellent hydrogen oxidation reaction activity, close to that of commercial 20 wt % Pt/C catalyst, and much lower oxygen reduction reaction activity than the commercial 20 wt % Pt/C catalyst. The lack of well-ordered Pt facets is responsible for the excellent selectivity of the HD-Pt/TiN materials toward hydrogen oxidation and oxygen reduction reac...
- Published
- 2018
19. A renewable wood-derived cathode for Li–O2 batteries
- Author
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Chunliang Zhu, Li Du, Huiyu Song, Shijun Liao, Zhiming Cui, Junming Luo, and Haibo Tang
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Materials science ,Renewable Energy, Sustainability and the Environment ,Carbonization ,business.industry ,Nanoparticle ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Cathode ,0104 chemical sciences ,law.invention ,Renewable energy ,Catalysis ,Areal capacity ,Chemical engineering ,law ,General Materials Science ,0210 nano-technology ,Porosity ,business ,Voltage - Abstract
In this work, we developed a renewable wood-derived cathode with well-aligned elongated microchannels for high-performance Li–O2 batteries. The cathode was obtained from natural wood following carbonization, activation, and then loading of RuO2 nanoparticles (4.15 wt%) as catalysts (RuO2/WD-C). The cathode has a three-dimensional, high stability carbon matrix, uniformly anchored catalysts, and well-aligned porous microchannels. As a result, the specific areal capacity of the assembled batteries exceeds 8 mA h cm−2 and the charge terminal potential is lower than 3.8 V at 0.1 mA cm−2. The energy efficiency was improved up to 91.9% and exceeded 87.1% after 100 cycles (curtailed capacity of 0.5 mA h cm−2 at 0.2 mA cm−2). Furthermore, the RuO2/WD-C cathode can be fully regenerated from a deep discharge–charge cycle or 100 curtailed-capacity cycles by simply washing with water. The areal capacity of the regenerated RuO2/WD-C cathode is comparable to the performance of the initial cathode. The cut-off voltage was above 2.6 V following 200 cycles. Even when regenerated for the second time, the RuO2/WD-C cathode still demonstrated almost the same high performance as the initial one, indicating its high stability and excellent renewability.
- Published
- 2018
20. Advanced Atomically Dispersed Metal–Nitrogen–Carbon Catalysts Toward Cathodic Oxygen Reduction in PEM Fuel Cells
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Haibo Tang, Yijie Deng, Yingjie Yang, Junming Luo, Shijun Liao, Xiaochang Qiao, Chunman Jia, Peng Rao, Xinlong Tian, Yijun Shen, Jing Li, and Bin Chi
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Materials science ,Renewable Energy, Sustainability and the Environment ,Membrane electrode assembly ,chemistry.chemical_element ,Proton exchange membrane fuel cell ,Nitrogen ,Oxygen reduction ,Catalysis ,Cathodic protection ,Metal ,chemistry ,Chemical engineering ,visual_art ,visual_art.visual_art_medium ,General Materials Science ,Carbon - Published
- 2021
21. A Co-doped porous niobium nitride nanogrid as an effective oxygen reduction catalyst
- Author
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Haibo Tang, Yingwei Li, Jianhuang Zeng, Junming Luo, Huiyu Song, Shijun Liao, and Xinlong Tian
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Niobium nitride ,Materials science ,Renewable Energy, Sustainability and the Environment ,Inorganic chemistry ,Doping ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,Nitride ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Catalysis ,chemistry.chemical_compound ,Transition metal ,chemistry ,X-ray photoelectron spectroscopy ,Electrical resistance and conductance ,General Materials Science ,0210 nano-technology ,Cobalt - Abstract
Transition metal nitrides have recently attracted significant interest as electrocatalysts for the oxygen reduction reaction (ORR) owing to their low electrical resistance and good corrosion resistance. In this paper, we describe the preparation of a Nb-based binary nitride material with a porous nanogrid morphology/structure. The catalyst exhibited good catalytic activity and high stability towards oxygen reduction. We also intensively investigated the effect that doping with a second transition metal had on the performance of the catalyst. We found that the ORR activity of NbN could be enhanced significantly by enriching the d electrons of Nb through doping with a second transition metal, and that doping with cobalt resulted in the best improvement. Our optimal catalyst, Nb0.95Co0.05N, had an ORR activity ∼4.6 times that of NbN (current density @ 0.6 V vs. the RHE). XPS results revealed that Co doping increased the proportion of Nb in a low-valence state, which may be one of the most important reasons for the enhanced performance. Another important reason is the high surface area resulting from the porous nanogrid morphology. As transition metal doping is an attractive way to enhance the activity of nitride catalysts, our work may provide an effective pathway to achieve this.
- Published
- 2017
22. Microstructure characterization and mechanical behavior of laser additive manufactured ultrahigh-strength AerMet100 steel
- Author
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Haibo Tang, Huaming Wang, Xu Cheng, A. Li, Xian-zhe Ran, and Dong Liu
- Subjects
010302 applied physics ,Austenite ,Materials science ,Bainite ,Mechanical Engineering ,Metallurgy ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Microstructure ,01 natural sciences ,Mechanics of Materials ,Ferrite (iron) ,0103 physical sciences ,Ultimate tensile strength ,General Materials Science ,Grain boundary ,Composite material ,0210 nano-technology ,Ductility ,Tensile testing - Abstract
Ultrahigh-strength AerMet100 steel thick plate was fabricated by laser additive manufacturing process. The as-deposited microstructures of the test steel were characterized using optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The mechanical properties were then examined using vickers-hardness test and tensile test. Results indicate that the as-deposited microstructures of the steel mainly consist of grain boundary allotriomorphic ferrite (GBA), grain interior irregular proeutectoid ferrite, plate-like upper bainite, needle-like lower bainite and retained austenite, which result in a good strength and some ductility anisotropy. The low deformation compatibility of specimen at the transverse direction (perpendicular to the deposition direction) mainly ascribes to the poor cracking resistance of the prior-austenite columnar grain boundary with coarse GBA phases. Compared to the almost intergranular cracking taken place in the transverse tensile specimen, the fracture mode of the longitudinal tensile specimen is a mixed mode of the predominant transgranular cracking and minor intergranular cracking.
- Published
- 2016
23. Mechanical Properties of Powder Metallurgy Nickel‐Based Superalloy Composite Reinforced by Low Content Graphene Nanosheets
- Author
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Jinwen Zou, Yu-Xi Gao, Haibo Tang, Xu Cheng, Zhuo Li, Xiaofeng Wang, Jie Yang, and Jia Li
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Superalloy ,Materials science ,Hot isostatic pressing ,Graphene ,law ,Powder metallurgy ,Metallurgy ,Composite number ,General Materials Science ,Nickel based ,Condensed Matter Physics ,law.invention - Published
- 2020
24. Microstructure characteristics and failure mechanisms of Ti-48Al-2Nb-2Cr titanium aluminide intermetallic alloy fabricated by directed energy deposition technique
- Author
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Yu Wu, Jiawei Wang, Qian Luo, Huaming Wang, Haibo Tang, and Xu Cheng
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Equiaxed crystals ,0209 industrial biotechnology ,Titanium aluminide ,Materials science ,Alloy ,Biomedical Engineering ,Nucleation ,Intermetallic ,02 engineering and technology ,engineering.material ,021001 nanoscience & nanotechnology ,Microstructure ,Industrial and Manufacturing Engineering ,chemistry.chemical_compound ,020901 industrial engineering & automation ,chemistry ,engineering ,General Materials Science ,Lamellar structure ,Grain boundary ,Composite material ,0210 nano-technology ,Engineering (miscellaneous) - Abstract
The high-energy input and thermal history during additive manufacturing lead to complex phase transformations in titanium aluminide alloy. This study mostly focuses on determining the solid-state phase transformation mechanisms during laser deposition and the failure mechanisms of alloys using molecular dynamics simulations. Because of the directional temperature gradient, columnar grains with fully lamellar microstructures are formed first after solidification. A narrow region just below the melting pool is reheated to high temperatures, thus enhancing the precipitation of new equiaxed grains. Multiple thermal cycles in the α + γ phase region promote the formation of massive γ phases (γm) at the grain boundaries. Finally, a nearly lamellar microstructure of alternating columnar and equiaxed grains with γm phases is formed. The deposited titanium aluminide alloy has good room and high-temperature (760 °C) tensile properties of 545 ± 9 and 471 ± 37 MPa, with elongations of 1.50 % ± 0.47 % and 1.50 % ± 0.45 %, respectively. The room and high-temperature samples both fail in the columnar grain region. The molecular dynamics simulations suggest that the interface between α2 and γm is the weakest, especially in the case of semicoherent interfaces (6° angle in the [1–10] direction), which provides good nucleation sites for cracks. Although the equiaxed grain regions contain several γm–α2 interfaces, the samples still fail in the columnar grain regions due to the increase in the cracking distance in the equiaxed regions caused by randomly oriented α2 + γ lamellae and the comparably good plasticity of the γm phases.
- Published
- 2020
25. Template-Free Preparation of 3D Porous Co-Doped VN Nanosheet-Assembled Microflowers with Enhanced Oxygen Reduction Activity
- Author
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Yuanyuan Dong, Mingrui Liu, Lina Liu, Jing Li, Haibo Tang, Junming Luo, Xinlong Tian, Huiyu Song, and Shijun Liao
- Subjects
Materials science ,Vanadium nitride ,Doping ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Catalysis ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Specific surface area ,Fuel cells ,General Materials Science ,0210 nano-technology ,Porosity ,Co doped ,Nanosheet - Abstract
Developing cheap and stable electrocatalysts is considered the key factor to achieve the large-scale application of fuel cells. In this paper, three-dimensional (3D) porous Co-doped vanadium nitride (VN) nanosheet-assembled microflowers are prepared with a facile solvothermal approach followed by nitridation at 500 °C in NH3. It is found that the microflower morphology and the Co doping both significantly enhance the oxygen reduction reaction (ORR) performance of the materials. Because the unique 3D porous structure provides higher specific surface area and more active sites as well as enriching the d electrons of V via doping, Co also improves the intrinsic activity of VN. Our optimal V0.95Co0.05N microflowers achieve a half-wave potential for the ORR of up to 0.80 V in 0.1 M KOH solution, which is almost comparable to that of commercial 20% Pt/C. More importantly, the catalysts show superior durability with little current decline (less than 12%) during chronoamperometric evaluation for over 25 000 s. Th...
- Published
- 2018
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