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Journal of Thermal Science 2012年第2期21卷 127-135页

作者： S. J. Geng N. x. Chen h. W. Zhang W. G. huang Institute of Engineering Thermophysics Chinese Academy of Sciences EO. Box 2706 Beijing 100190 China

It is well known that increasing the rotational velocity is an effective way to increase the total pressure ratio. With increasing flow velocity especially under the condition of transonic flow in the supersonic region, where exist strong shock waves, the shock wave loss becomes main and important. Simultaneously, there occurs boundary layer separation due to the shock wave / boundary layer interaction. In the present paper the transonic compressor blades were studied and analyzed to find a proper and simple way to reduce the shock wave loss by optimizing the suction surface configuration or controlling the gradient of isentropic Mach number on the suction surface. A Navier-Stokes solver combined with a modified design algorithm was developed and used. The NASA single rotor for transonic flow compressor was served as a numerical example to show the effectiveness of this method. Two cases for both original and modified rotors were analyzed and compared.

关键词： Transonic compressor shock wave loss efficiency improvement blade optimization

Pulsed dynamic electrolysis enhanced PEMWE hydrogen production:Revealing the effects of pulsed electric fields on protons mass transport and hydrogen bubble escape

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Journal of Energy Chemistry 2025年第1期100卷 201-214页

作者： xuewei Zhang Wei Zhou Yuming huang Liang xie Tonghui Li huimin Kang Lijie Wang Yang Yu Yani Ding Junfeng Li Jiaxiang Chen Miaoting Sun Shuo Cheng xiaoxiao Meng Jihui Gao Guangbo Zhao School of Energy Science and Engineering Harbin Institute of Technology China Datang Technology Innovation Co. Ltd

The transition of hydrogen sourcing from carbon-intensive to water-based methodologies is underway,with renewable energy-powered proton exchange membrane water electrolysis （PEMWE） emerging as the preeminent pathway for hydrogen *** remarkable advancements in this field,confronting the sluggish electrochemical kinetics and inherent high-energy consumption arising from deteriorated mass transport within PEMWE systems remains a formidable *** impediment stems primarily from the hindered protons mass transfer and the untimely hydrogen bubbles *** address these challenges,we harness the inherent variability of electrical energy and introduce an innovative pulsed dynamic water electrolysis *** to constant voltage electrolysis (hydrogen production rate:51.6 m L h-1,energy consumption:5.37 kWh Nm-3h2),this strategy (hydrogen production rate:66 m L h-1,energy consumption:3.83 kWh Nm-3h2) increases the hydrogen production rate by approximately 27%and reduces the energy consumption by about 28%.Furthermore,we demonstrate the practicality of this system by integrating it with an off-grid photovoltaic （PV） system designed for outdoor operation,successfully driving a hydrogen production current of up to 500 mA under an average voltage of approximately 2 *** combined results of in-situ characterization and finite element analysis reveal the performance enhancement mechanism:pulsed dynamic electrolysis （PDE） dramatically accelerates the enrichment of protons at the electrode/solution interface and facilitates the release of bubbles on the electrode *** such,PDE-enhanced PEMWE represents a synergistic advancement,concurrently enhancing both the hydrogen generation reaction and associated transport *** promising technology not only redefines the landscape of electrolysis-based hydrogen production but also holds immense potential for broadening its application across a diverse spectrum of electrocatalytic endeavors.

关键词： Electrolysis

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银基催化剂调控及其甲醛催化氧化性能研究

大连理工大学学报 2025年第1期65卷 17-22页

作者：黄彬曲振平大连理工大学环境学院辽宁大连116024

银基催化剂具有较好的氧化能力,在环境催化领域具有良好的应用前景.采用等体积浸渍法制备银基催化剂,考察了助剂种类、预处理气氛和温度、载体孔道结构等制备工艺条件对银基催化剂上甲醛(hChO)催化氧化性能的影响.实验结果表明,在6%的Ag... 详细信息

银基催化剂具有较好的氧化能力,在环境催化领域具有良好的应用前景.采用等体积浸渍法制备银基催化剂,考察了助剂种类、预处理气氛和温度、载体孔道结构等制备工艺条件对银基催化剂上甲醛(hChO)催化氧化性能的影响.实验结果表明,在6%的Ag/SBA-15催化剂中添加3%的Fe助剂能显著提高催化剂的hChO催化氧化性能,先后采用O_(2)和h_(2)处理有助于提高催化剂活性,载体孔道结构对hChO催化氧化活性影响较小,采用共浸渍法制备的银基催化剂的性能优于两步浸渍法制备的催化剂的性能.其中采用共浸渍法制备的AgFe/SBA-15催化剂,在O_(2)(600℃)和h_(2)(400℃)先后处理后,表现出良好的hChO催化氧化性能,在75℃时可将hChO完全转化为CO_(2)和h_(2)O.

关键词：甲醛催化氧化银基催化剂制备工艺条件

Uncovering the softening mechanism and exploring the strengthening strategies in extremely fine nanograined metals:A molecular dynamics study

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Journal of Materials Science & Technology 2022年第14期109卷 186-196页

作者： h.R.Peng Z.Y.Jian C.x.Liu L.K.huang Y.M.Ren F.Liu School of Materials and Chemical Engineering Xi’an Technological UniversityXi’an 710021China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China

The strength of polycrystalline metals increases with decreasing grain size,following the classical hallPetch ***,this relationship fails when softening occurs at very small grain sizes(typically less than 10 to 20 nm),which limits the development of ultrahigh-strength *** this work,using columnar-grained nanocrystalline Cu-Ag‘samples’,molecular dynamics simulations were performed to investigate the softening mechanism and explore the strengthening strategies(e.g.,formation of solid solution or grain boundary(GB)segregation)in extremely fine nanograined ***,the softening of pure metals is induced by atomic sliding in the GB layer,rather than dislocation activities in the grain interior,although both occur during *** solid solution lowers the stacking fault energy and increases the GB energy,which leads to the softening of NC *** segregation stabilizes GB structures,which causes a notable improvement in strength,and this improvement can be further enhanced by optimizing the solute concentration and GB *** work deepens the understanding of the softening mechanism due to atomic sliding in the GB layer and the strengthening mechanism arising from tailoring the GB stability of immiscible alloys and provides insights into the design of ultrahighstrength materials.

关键词： Softening Strengthening Cu-Ag alloy Molecular dynamics Nanocrystalline

Effects of welding parameters and post-heat treatment on mechanical properties of friction stir welded AA2195-T8 Al-Li alloy

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Journal of Materials Science & Technology 2018年第1期34卷 219-227页

作者： J. Zhang x.S. Feng J.S. Gao h. huang Z.Q. Ma L.J. Guo Technical Center Shanghai Aerospace Equipments Manufacturer Shanghai 200245. China

In this study, the effects of main welding parameters （rotation speed （ω） and welding speed （υ）） on the microstructure, micro-hardness distribution and tensile properties of friction stir welded （FSW） 2195-T8 Al-Li alloy were investigated. The effects of T6 post-treatments at different solution and aging conditions on the mechanical properties and microstructure characteristics of the FSW joints were also investigated. The results show that with increasing to and v, both strength and elongation of the joints increase first, and then decrease with further increase of ω and υ. All the joints under varied welding parameters show significant strength loss, and the strength reaches only 65% of the base metal, The effect of T6 post-heat treatment on the mechanical properties of the joints depends on the solution and aging conditions. Two heat treatment processes （480 ℃×0.5 h quenching＋ 180 ℃× 12 h, 520 ℃× 0.5 h quenching＋ 180 ℃×12h aging） are found to increase the joint strength. Furthermore, low temperature quenching （480℃） is more beneficial to the joint strength. The joint strength can reach 85% of the base metal. Whereas both low temperature aging （140 ℃× 56h） and stepped aging （ 100 ℃× 12 h ＋ 180 ℃× 3 h） processes decrease the joint strength. After heat treatment all the joints show decreased ductility due to the obvious grain coarsening in the nugget zone （NZ） and thermo-mechanically affected zone （TMAZ）.

关键词： 2195-T8 Al-Li alloy Friction stir welding Welding parameters Post-heat treatment

Recent development in the application of bulk metallic glasses

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Journal of Materials Science & Technology 2022年第36期131卷 115-121页

作者： K.Gao x.G.Zhu L.Chen W.h.Li x.xu B.T.Pan W.R.Li W.h.Zhou L.Li W.huang Y.Li Dongguan Yihao Metal Technology Co.Ltd Dongguan 523686China Dongguan Eontec Co.Ltd Dongguan 523686China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

Over the past decades,considerable efforts have been made in the commercial application of bulk metallic glasses(BMGs).Despite great challenges faced by the industrial players,significant progress has been achieved,and millions of commercial products for various kinds of applications have been shipped around the *** in this paper,we shall present the alloys suitable for the actual products in the application and discuss the merits of the processing technique of BMGs over the existing processing techniques and *** importantly we demonstrate the typical examples of products over the past few ***,future directions of the industrialization of BMGs are also discussed.

关键词： Bulk metallic glasses Commercial application Alloy design Products

Mechanical properties of cocoons constructed consecutively by a single silkworm caterpillar,Bombyx mori

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Acta Mechanica Sinica 2008年第2期24卷 151-160页

作者： S.Q.huang h.P.Zhao x.Q.Feng W.Cui Z.Lin M.Q.xu Department of Engineering Mechanics FML Tsinghua University Beijing 100084 China Department of Sericulture Shandong Agriculture University Tai'an 271018 China Department of Landscape Architecture Human Environment-Biological Polytechnic College. Hengyang 421005 China

Most animals have the ability to adapt, to some extends and in different ways, the variation or disturbance of environment. In our experiments, we forced a silkworm caterpillar to spin two, three or four thin cocoons by taking it out from the cocoon being constructed. The mechanical properties of these cocoons were studied by static tensile tests and dynamic mechanical thermal analysis. Though external disturbances may cause the decrease in the total weight of silk spun by the silkworm, a gradual enhancement was interestingly found in the mechanical properties of these thin cocoons. Scanning electron microscopy observations of the fractured specimens of the cocoons showed that there exist several different energy dissipation mechanisms occurred simultaneously at macro-, meso-, and micro-scales, yielding a superior capacity of cocoons to adsorb the energy of possible attacks from the outside and to protect efficiently its pupa against damage. Through evolution of millions of years, therefore, the silkworm Bombyx mori seems to have gained the ability to adapt external disturbances and to redesign a new cocoon with optimized protective function when its first cocoon has been damaged for some reasons.

关键词： Silk Silkworm cocoon Mechanical property Biomimetics

Microstructural features of Ti-6Al-4V manufactured via high power laser directed energy deposition under low-cycle fatigue

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Journal of Materials Science & Technology 2021年第24期83卷 18-33页

作者： Y.M.Ren x.Lin h.O.Yang h.Tan J.Chen Z.Y.Jian J.Q.Li W.D.huang School of Materials and Chemical Engineering Xi’an Technological UniversityXi’an710021China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an710072China

Laser additive manufacturing(LAM)technique has unique advantages in producing geometrically complex metallic ***,the poor low-cycle fatigue property(LCF)of LAM parts restricts its widely ***,the microstructural features of a Ti-6 Al-4 V alloy manufactured via high power laser directed energy deposition subjected to low-cycle fatigue loading were *** fatigue loading,the microstructure of the as-deposited parts was found to exhibit a non-homogeneous distribution of columnar prior-βgrains(200-4000μm)at various scanning velocities(300-1500 mm/min)and relatively coarseα-laths(1.0-4.5μm).Under cyclic loading,fatigue microcracks typically initiated within the alignedαphases in the preferred orientation(45°to the loading direction)at the surface of the fatigue *** Ti-6 Al-4 V exhibited a single straight dislocation character at low strain amplitudes(high strain amplitudes(>1.1%).In addition,dislocation substructure features,such as dislocation walls,stacking faults,and dislocation networks,were also *** findings may provide opportunities to understand the fatigue failure mechanism of additive manufactured titanium parts.

关键词： Laser additive manufacturing Directed energy deposition Titanium alloy Low-cycle fatigue Microstructure

Towards creep property improvement of selective laser melted Ni-based superalloy IN738LC

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Journal of Materials Science & Technology 2022年第17期112卷 301-314页

作者： h.Y.Song M.C.Lam Y.Chen S.Wu P.D.hodgson x.h.Wu Y.M.Zhu A.J.huang Monash Centre for Additive Manufacturing 15-17 Normanby RdNotting HillVIC 3168Australia Department for of Materials Science and Engineering Monash UniversityClaytonVIC 3800Australia Monash Centre for Electron Microscopy 10 Innovation WalkClaytonVIC 3800Australia Institute for Frontier Materials Deakin UniversityVIC 3216Australia

Nickel-based superalloy IN738LC produced by selective laser melting(SLM)exhibits inferior hightemperature creep properties than its cast counterparts due to relatively smaller grain size,particularly for the plane normal to the building *** work studied effects of post heating strategy on the microstructure and especially the grain size to improve the high temperature creep *** asbuilt microstructure exhibited a fine grain size and large quantities of MC carbides that could effectively hinder grain *** was found that unconventional two-step heat treatments could lead to substantial grain growth,and the effect is particularly prominent at a specific *** ease of grain growth was explained after classifying the microstructural evolution(boundary carbide transformation)during each heating step and related to the reduced grain boundary pinning force from MC *** tests validated the effect of the new heat treatment scheme on the SLM-processed IN738LC at 850℃.An extended creep fracture life(1.5 to 4 times improvement)and lower secondary creep rates were achieved with samples subjected to the newly optimized two-step heat *** complete creep curves are also firstly presented for SLM-IN738LC,confirming the effectiveness of grain growth and highlighting the importance of dedicated heat treatment for SLM superalloys.

关键词： Selective laser melting IN738LC alloy Creep properties heat treatments Grain structure

Constructing two-scale network microstructure with nano-Ti5Si3 for superhigh creep resistance

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Journal of Materials Science & Technology 2019年第8期35卷 1532-1542页

作者： Y.Jiao L.J.huang S.L.Wei h.x.Peng Q.An S.Jiang L.Geng State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001 China Center of Analysis and Measurement Harbin Institute of TechnologyHarbin 150001 China Department of Materials Science and Engineering Massachusetts Institute of TechnologyCambridge MA02139 USA Institute for Composites Science Innovation (InCSI) School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027 China

The improvement of mechanical properties must be achieved by designing and constructing more suitable microstructure,such as hierarchical *** order to significantly enhance the creep resistance of titanium matrix composites(TMCs),two-scale network microstructure was constructed including the first-scale network(h micro-TiB whisker(TiBw)reinforcement and the second-scale network(h nano-Ti5Si3 reinforcement by powder metallurgy and in-situ *** results showed that the creep rate of the composite was remarkably reduced by an order of magnitude compared with the Ti6Al4V alloy at 550℃,600℃,650℃ under the stresses between 100 MPa and 350 ***,the rupture time of the composite was increased by 20 times,compared with that of the Ti6Al4 Valloy at 550℃/300 *** superior creep resistance could be attributed to the hierarchical *** micro-TiBw reinforcement in the first-scale network boundary contributed to creep resistance primarily by blocking grain boundary sliding,while the nano-Ti5Si3 particle in the second-scale network boundary mainly by hindering phase boundary *** addition,the nano-Ti5Si3 particle was dissolved,and precipitated with smaller size than the primary *** phenomenon was attributed to Si element diffusion under high temperature and external stress,which could further continuously enhance the creep ***,the creep rate during steady-state stage was significantly decreased,which manifested superior creep resistance of the composite.

关键词： Titanium matrix composite Two-scale network microstructure Nano-Ti5Si3 Creep Powder metallurgy