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Oxygen and Nitrogen Effects on MC Carbide in K465 Nickel-Base Superalloy

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稀有金属材料与工程 2009年第A3期38卷 13-16页

作者： Wang L N Zheng q Sun x f Guan h R hu Z q Institute of Metals Research Chinese Academy of Sciences Shenyang 110015 China

Effects of oxygen and nitrogen on MC carbide in nickel-base superalloy K465 were investigated, because neither of the two gas elements was found to decide MC carbide morphology monotonically. The morphology of MC carbide under alloy solidified in conventional investment casting condition was observed to transform from script-type to block-type with the total oxygen and nitrogen content (gas content) in samples rising up from 1.2×10-6 mol/g to 2.6×10-6 mol/g. The area fraction and composition of the MC carbide also varied with increase of gas content. however, the morphology of MC carbide kept to be script-type even when gas content was up to 3.4×10-6 mol/g in samples solidified with a much higher cooling rate. These results indicate that effects of gas content on formation of MC carbide can be observed in specimens solidified with low cooling rate, but such changes in MC carbide cannot be found when the cooling rate is high.

关键词：氧碳化物氮含量物理性能碳化物

A mild, configurable, flexible CoNi-LDh（v）/Zn battery based on h-vacancy-induced reversible Zn2+ intercalation

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Journal of Energy Chemistry 2025年第1期100卷 498-508页

作者： xinyue Cheng Dingsheng Wu hao Gao qingqing Wang Pengfei Lv Sam S.Yoon qufu Wei Key Laboratory of Eco-textiles Ministry of Education Jiangnan University School of Mechanical Engineering Korea University

flexible Zn-based batteries have attracted increasing research interest as essential components of wearable energy storage ***,the advancement of flexible aqueous Zn-based batteries based on Co-Ni layered double hydroxide （CoNi-LDh） as the cathode material is hampered by their poor cycling stability and the corrosiveness of alkaline ***,CoNi-LDh nanosheets enriched with h vacancies (CoNi-LDh（v）) were constructed on a flexible carbon cloth （CC） substrate via electrochemical deposition and *** Zn-based battery comprising CoNi-LDh（v）@CC as the cathode exhibited highly reversible conversion reactions and stable operation in 3 M ZnSO4electrolyte （ph=4）.The battery delivered an excellent specific capacity (225 mA h g-1,0.26 mA h cm-2),acceptable cycling stability（53.9%,900 cycles）,and high discharging *** abundant h vacancies served as active sites for the reversible intercalation of Zn2+and the extravasation of NO3-generated channels and space for Zn2+transport and storage,together enabling an excellent Zn2+storage ***,a sandwich-structured solid-state CoNi-LDh（v）@CC//Zn@CC battery was fabricated and was found to exhibit a noteworthy electrochemical performance and mechanical *** a proof of concept,the unencapsulated battery powered a digital watch under various deformation conditions and operated stably for 80 ***,the flexible battery displayed outstanding customizability,maintaining an open-circuit voltage of 1.42 V even after being cut *** proposed engineering strategy contributes to the realization of textiles with truly wearable energy-storage devices.

关键词： CoNi/Zn battery h vacancies Mild aqueous electrolyte Tailorable battery Wearable energy storage device

Curvature-induced noncommutativity of two different components of momentum for a particle on a hypersurface

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Communications in Theoretical Physics 2021年第2期73卷 73-77页

作者： Z Li x Yang q h Liu School for Theoretical Physics School of Physics and ElectronicsHunan UniversiyChangsha 410082China School of Materials Science and Engineering Guilin University of Electronic TechnologyGuilin541004China Synergetice Innovation Center for quantum Efects and Applications(SICqEA) Hunan Normal UniversityChangsha 410081China

As a nonrelativistic particle constrained to remain on an(N−1)-dimensional((N≥2))hypersurface embedded in an N-dimensional Euclidean space,two different components pi and pj(i,j=1,2,3,...N)of the Cartesian momentum of the particle are not mutually commutative,and explicitly commutation relations[p^(^)_(i),p^(^)_(j)](≠0) depend on products of positions and momenta in uncontrollable *** generalized Dupin indicatrix of the hypersurface,a local analysis technique,is utilized to explore the dependence of the noncommutativity on the curvatures around a local point of the *** first finding is that the noncommutativity can be grouped into two categories;one is the product of a sectional curvature and the angular momentum,and another is the product of a principal curvature and the *** second finding is that,for a small circle lying a tangential plane covering the local point,the noncommutativity leads to a rotation operator and the amount of the rotation is an angle anholonomy;and along each of the normal sectional curves centering the given point the noncommutativity leads to a translation plus an additional rotation and the amount of the rotation is one half of the tangential angle change of the arc.

关键词： constrained motion quantization hypersurface Dirac brackets geometric momentum

Microstructure evolution and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with different prestrain levels

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Journal of Materials Science & Technology 2024年第4期171卷 80-93页

作者： Y.h.Zhang h.Li Z.W.Yang x.Liu q.f.Gu State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of high-Performance Precision forming Technology and Equipment Northwestern Polytechnical UniversityXi’an 710072China

Ni_(47)Ti_(44)Nb_(9)shape memory alloy(SMA)is a promising material in the aerospace field due to its wide transformation *** application of shape memory effect depends on multistep thermomechan-ical loading,viz.,low-temperature deformation and subsequent heating to ***-temperature deformation prestrain plays a pivotal role in shape memory properties tailoring of SMA ***,microstructure evolution and deformation mechanisms of Ni_(47)Ti_(44)Nb_(9)SMA subjected to vari-ous prestrain levels are still *** this end,microstructure evolution and shape memory behaviors of Ni_(47)Ti_(44)Nb_(9)alloy subjected to multistep thermomechanical loading with prestrain levels of 8%-16%at-28℃(M_(s)+30℃)were *** results demonstrate that the stress-strain curve of the specimen exhibits four distinct stages at a maximal prestrain of 16%.Whereas stageⅡand stageⅢend at prestrains of∼8%and∼12%,*** stageⅡ,the stress-induced martensitic transformation is accompanied by the dislocation slip of the NiTi matrix andβ-Nb *** stageⅢ,in addition to the higher density of dislocations and further growth of stress-induced martensite variants(SIMVs),(001)compound twins are introduced as a result of the(001)deformation twinning in stress-induced ***{20-1}martensite twins are gradually introduced in stageⅣ.Correspondingly,after subsequent unloading and heating,a higher density of{114}austenite twins form in the specimen with a larger prestrain of 16%.With increasing prestrain from 8%to 16%,the recoverable strainε_(re)^(T)upon heating increases first and then ***ε_(re)^(T)obtains a maximum of 7.03%at 10%prestrain and de-creases to 6.17%at 16%*** increase ofε_(re)^(T)can be attributed to the formation of new SIMVs,the further growth of existing SIMVs,and the recoverable(001)compound *** the decrease ofε_(re)^(T)is mainly associated with the irrecoverable strain by{20−1}martensite *** effe

关键词： Ni_(47)Ti_(44)Nb_(9)shape memory alloy Wide transformation hysteresis Thermomechanical loading Microstructure evolution Shape memory behaviors Stress-induced martensitic transformation Deformation twinning

Interface defeat studies of long-rod projectile impacting on ceramic targets

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Defence Technology（防务技术） 2020年第1期16卷 50-68页

作者： Y.x.Zhai h.Wu q.fang Amy Engineering University of PLA Nanjing210007China Research Institute of Structural Engineering and Disaster Reduction College of Civil EngineeringTongji UniversityShanghai200092China

The interface defeat phenomenon always occurs when a long-rod projectile impacting on the ceramic target with certain velocity,i.e.,the projectile is forced to flow radially on the surface of ceramic plates for a period of time without significant *** defeat has a direct effect upon the ballistic performance of the armor piercing projectile,which is studied numerically and theoretically at ***,by modeling the projectiles and ceramic targets with the SPh(Smoothed Particle hydrodynamics)particles and Lagrange finite elements,the systematic numerical simulations on interface defeat are performed with the commercial finite element program *** different responses,i.e.,complete interface defeat,dwell and direct penetration,are reproduced in different types of ceramic targets(bare,buffered,radially confined and oblique).furthermore,by adopting the validated numerical algorithms,constitutive models and the corresponding material parameters,the influences of projectile(material,diameter,nose shape),constitutive models of ceramic(Jh-1 and Jh-2 models),buffer and cover plate(thickness,constraints,material),as well as the prestress acted on the target(radial and hydrostatic) on the interface defeat(transition velocity and dwell time) are syste matically ***,based on the energy conservation approach and taking the strain rate effect of ceramic material into account,a modified model for predicting the upper limit of transition velocity is proposed and *** present work and derived conclusions can provide helpful reference for the design and optimization of both the long-rod projectile and ceramic armor.

关键词： Interface defeat Ceramic Transition velocity Numerical simulation Parametric study

Precipitation of multi-type nano-quasicrystals in a Mg-Zn-Y alloy

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Journal of Magnesium and Alloys 2024年第3期12卷 997-1008页

作者： W.Z.Wang x.Z.Zhou L.f.Zhang h.q.Ye Z.q.Yang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of ScienceShenyang 110016China Ji hua Laboratory Foshan 528251China foshan University Foshan 528231China

Mg-6Zn-1Y(at.%)ribbons with strengthening precipitates of multi-type nanoquasicrystals were prepared by melt-spinning followed by aging *** evolution of the rapidly solidified ribbons during isothermal aging was comprehensively studied using various electron microscopy *** new kinds of decagonal quasicrystals were formed in aged ribbons,in addition to precipitation of nanometer icosahedral ***-resolution observations reveal that both decagonal quasicrystals can be modeled by quasiperiodic tiling with decagonal clusters of 2.5 nm in diameter,but overlap of neighboring clusters in both decagonal quasicrystals is different from the Gummelt model observed in other quasicrystals.A shell composed of complex Laves Mg-Zn domains was formed surrounding each decagonal quasicrystal precipitate upon prolonged *** addition,all kinds of nanoprecipitates exhibit excellent structure and size stability at 573 *** findings may have implications for not only fundamental studies about quasicrystals,but also microstructural manipulation of high-performance Mg alloys.

关键词： quasicrystal Mg alloys Rapid solidification Scanning-transmission electron microscopy.

Microstructure and mechanical properties of Mg-to-Al dissimilar welded joints with an Ag interlayer using ultrasonic spot welding

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Journal of Magnesium and Alloys 2020年第2期8卷 552-563页

作者： h.Peng D.L.Chen x.f.Bai P.q.Wang D.Y.Li x.q.Jiang College of Engineering and Technology Southwest UniversityTiansheng Road 2Beibei DistrictChongqing 400715China Department of Mechanical and Industrial Engineering Ryerson University350 Victoria StreetTorontoOntario M5B 2K3Canada School of Materials and Energy Southwest UniversityTiansheng Road 2Beibei DistrictChongqing 400715China Department of Chemical and Materials Engineering University of AlbertaEdmontonAlberta T6G 1H9Canada

Lightweight ZEK100-0 Mg alloy and A16022-T43 Al alloy with an Ag interlayer were joined via ultrasonic spot welding(USW),focusing on the microstructural change and tensile lap shear strength of the welded joints in relation to welding ***/Al interface was superseded by Mg/Ag and Al/Ag interfaces,and unfavorable Mg门A-intermetallic compound was *** foil was observed to be intact in the nugget center,while it was broken or dissolved at the nugget edge at high welding energy *** diffusion layer at the Mg/Ag interface consisted of two distinctive sub-layers:Mg3Ag intermetallic compound adjoining Ag foil,and Mg3Ag-l-Mg eutectic structure adjacent to *** a thin diffusion layer consisting mainly of Ag3Al occurred al lhe Al/Ag *** tensile lap shear strength first increased,reached its peak value,and then decreased with increasing welding *** shear strength achieved in the present study was〜31%higher than that of the joint without *** failure occurred at all energy levels,with Ag foil particles or fragments being stuck on both Mg and Al sides due to its intense interaction with Mg and Al via accelerated diffusion during *** results obtained pave the way for the challenging dissimilar welding between Mg and Al alloys.

关键词： Magnesium alloy Aluminum alloy Ultrasonic spot welding Ag interlayer Microstructure Tensile lap shear strength

PARTICLE SIZE AND MICROSTRUCTURE Of Ni NANOPOWDERS PREPARED BY ANODIC ARC PLASMA

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Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 209-216页

作者： Z.q.Wei h.x.qiao J.f.Dai W.J.feng q.Wang P.x.Yan SchoolofSciences LanzhouUniversityofTechnologyLanzhou730050China CollegeofCivilEngineering LanzhouUniversityofTechnologyLanzhou730050China SchoolofPhysicalScienceandTechnology LanzhouUniversityLanzhou730000China

Pure Ni nanopowders were successfully prepared by the method of anodic arc disch arged plasma with homemade experimental apparatus. The particle size, mircostruc ture and morphology of the particles by this process were characterized via x-ra y powder diffraction (xRD), transmission electron microscopy (TEM) and the corre sponding selected area electron diffraction (SAED); The specific surface area an d pore parameters were investigated by multi-point full analysis of nitrogen ads orption-desorption isotherms at 77K by Brunauer- Emmett-Teller (BET) surface are a analyzer; The chemical composition were determined by x-ray energy dispersive spectrometry (xEDS) equipped in SEM and element analyze instrument. The experime nt results indicate that the samples by this method with high purity,the crystal structure of the particles is as same as the bulk material, is fcc structure, w ith average particle sizes about 47nm, ranging from 20 to 70nm, and distributed uniformly in spherical chain shapes, the specific surface areavis 14.23m2/g, po re volume of pore is 0.09cm3/g and average pore diameter is 23nm.

关键词： anodic arc plasma Ni nanopowder particle size structure composition.

Numerical study of convective heat transfer of a supersonic combustor with varied inlet flow conditions

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Acta Mechanica Sinica 2019年第5期35卷 943-953页

作者： W.h.fan f.q.Zhong S.G.Ma x.Y.Zhang State Key Laboratory of high Temperature Gas Dynamics Institute of MechanicsChinese Academy of SciencesBeijing 100190 China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China

Characteristics of convective heat transfer of a supersonic model combustor with variable inlet flow conditions were studied by numerical simulation in this *** three-dimensional flow and wall heat flux at different air inlet Mach numbers of 2.2,2.8 and 3.2 were studied numerically with Reynolds-averaged Navier-Stokes equations with a shear-stress transport(SST)k-ωturbulence model and a three-step reaction ***,ethylene was chosen as the fuel,and the fixed fuel-to-air equivalence ratio is 0.8 in all cases in this *** results of the simulations indicate that wall heat flux distribution of the combustor is very non-uniform with several peaks of wall heat flux at varied *** the low inlet Mach number of 2.2,a shock train structure is formed in the isolator,and three peaks of wall heat flux are located respectively on the backward face of the cavity,on the side wall near the fuel injection and on the bottom wall near the injection holes,and a maximum wall heat flux reaches 5.4 MW/*** the medium inlet Mach number of 2.8,there exists a much shorter shock structure with three peaks of wall heat flux similar to that of Mach number ***,as the inlet Mach number increased to 3.2,there is no shock structure upstream of fuel injections,and the combustor flow is in a supersonic mode with different locations and values of wall heat flux *** statistical results of wall heat loading show that the change of total wall heat is not monotonic with the increase of inlet Mach number,and the maximum appears in the case of Mach number being ***,for all the cases,the bottom wall takes up more than 50%of the total heat loading.

关键词： Wall heat flux Numerical simulation Ethylene Supersonic combustor