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Effect of interlayer addition on microstructure and mechanical properties of NiTi/stainless steel joint by electron beam welding

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journal of Materials Science & Technology 2021年第2期61卷 16-24页

作者： H.Niu H.C.jiang M.j.zhao L.j.Rong CAS Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of ScienceShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei230026China

NiTi/Stainless Steel(SS) sheets have been welded via a vacuum electron beam welding process, with three methods(offsetting electron beam to SS side without interlayer, adding Ni interlayer and adding Fe Ni interlayer), to promote mechanical properties of the Ni Ti/SS joints. The joints with different interlayers are all fractured in the weld zone near the Ni Ti side, which is attributed to the enrichment of intermetallic compounds including Fe2 Ti and Ni3 Ti. The fracture mechanisms of different joints are strongly dependent on the types of interlayers, and the joints without interlayer, adding Ni interlayer and adding Fe Ni interlayer exhibit cleavage fracture, intergranular fracture and mixed fracture composed of cleavage and tearing ridge, respectively. Compared with the brittle laves phase Fe2 Ti, Ni3 Ti phase can exhibit certain plasticity, block the crack propagation and change the direction of crack propagation. The composite structure of Ni3 Ti and Fe2 Ti will be formed when the Fe Ni alloy is taken as the interlayer, which provides the joint excellent mechanical properties, with rupture strength of 343 MPa.

关键词： NiTi Stainless steel Electron beam welding Interlayer Mechanical property

Mechanical Properties and Defective Effects of 316LN Stainless Steel by First-Principles Simulations

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journal of Materials Science & Technology 2011年第11期27卷 1029-1033页

作者： X.Q. Li j.j. zhao j.C. Xu X. Liu Key Laboratory of Materials Modification by Laser Ion and Electron Beams Ministry of Education Dalian University of Technology Dalian 116024 China College of Advanced Science and Technology Dalian University of Technology Dalian 116024 China School of Chemical Engineering Dalian University of Technology Dalian 116024 China

In current International Thermonuclear Experimental Reactor （ITER） design, the 316LN austenitic stainless steel （316LN SS） is used for first-wall/blanket structures. Thus, it is necessary to study the fundamental mechanical properties and irradiation effect of 316LN SS. A random solid solution model of Fe-Cr-Ni-Mn- Mo-Si alloy is used for describing 310LN S$. Using first-principles approaches, the elastic constants and ideal strength of the alloy were calculated. Such alloy exhibits good ductile behavior according to the theoretical values of Cauchy pressure and ratio of bulk modulus and shear modulus. Within the 256-atom supercell, inclusion of single vacancy defect further enhances the ductility of the alloy, and the existence of interstitial （Fe, H, He） atoms enhances the Young＇s modulus.

关键词： Stainless steel Mechanical properties Vacancy Interstitial

Simplified design of rock cavern concrete lining to resist shock loading

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journal of Central South University 2010年第5期17卷 1087-1094页

作者： zhao P j LOK T S 殷志强周子龙 Butler Partners Pty Ltd Queensland 4006 Australia Protective Technology Research Centre School of Civil and Environmental Engineering Nanyang Technological University Singapore 639798 Singapore School of Resources and Safety Engineering Central South University Changsha 410083 China

A simplified method was proposed for the design of concrete lining in underground rock cavern/tunnel against shock loading. The loading may result from the detonation of explosives on ground surface or ground penetration projectiles exploding adjacent to the cavern/tunnel. The resulting problem necessitates the solution of the dynamics of a beam loaded by a transient pressure uniformly distributed over the span. According to mechanical characteristics of the system with rock bolt and shotcrete, a dynamic support design method based on equivalent single degree of freedom （SDOF） was put forward. The SDOF method was applied to obtaining the maximum displacement at the mid-span of the beam, which is often the controlling factor in the blast-resistant design. In the formulation of the problem, the proposed method combines the phenomena of spalling and structural dynamics theory. An example is provided to demonstrate the applicability of this simplified method.

关键词： tunnel lining design shock loading dynamic response rock cavern

Photodetachment of a Homo-Nuclear Linear Tetra-Atomic Negative Molecular Ion

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Chinese Physics Letters 2012年第4期29卷 61-64页

作者： A.Rahman Iftikhar Ahmad A.Afaq H.j.zhao Department of Physics Hazara UniversityMansehraPakistan Department of Physics University of MalakandChakdaraPakistan Centre of Excellence in Solid State Physics University of the PunjabQuid-e-Azam CampusLahore-54590Pakistan School of Physics and Information Science Shanxi Normal UniversityLinfen 041004

The photodetachment of a homo-nuclear linear tetra-atomic negative molecular ion is studied theoretically for an arbitrary laser *** expression for the total cross section is obtained by using an extended version of the two center model,where each center acts as a source of coherent photodetached-electron *** oscillations on observation plane,placed at a large distance from the ion,are *** amplitude of these oscillations is maximum when the laser polarization is parallel to the molecular ***,the amplitude decreases as the angle between the laser polarization and molecular axis increases and consequently vanishes when they are perpendicular to each *** is also found that if the distance between the adjacent centers is very small or very large,then the ampplitude of oscillations is negligibly small.

关键词： Strong centers polarization

A brief review：experimental investigation of zonal flows and geodesic acoustic modes in fusion plasmas

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Plasma Science and Technology 2018年第9期20卷 72-84页

作者： K j zhao j Q DONG j Q LI L W YAN Southwestern Institution of Physics Chengdu 610041People＇s Republic of China

Zonal flows self-generated by turbulence play an important role in regulating turbulence,reducing transport level,and thus improve plasma confinement in fusion *** zonal flows and geodesic acoustic modes have been identified in various *** related issues,such as the poloidal and toroidal symmetries,coupling to turbulence,effects on turbulence and transport,nonlinear energy transfer between turbulence and zonal flows,dependence of the plasma parameters,roles in the confinement regime transitions etc are overviewed briefly in this *** interaction between zonal flows and magnetic islands is emphasized.

关键词： zona flow tokamak turbulence fusion plasma

Photoluminescence from Silicon Nanocrystals in Encapsulating Materials

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journal of Materials Science & Technology 2013年第3期29卷 221-224页

作者： Z.Deng X.D.Pi j.j.zhao D.Yang State Key Laboratory of Silicon Materials and Department of Materials Science and Engineering Zhejiang University

Naturally oxidized freestanding silicon nanocrystals （Si NCs） are incorporated in commonly used encapsulating materials to explore the photoluminescent application of Si NCs in device structures such as solid-state lighting light-emitting diodes （LEDs） and solar cells. The quantum yield of Si NCs before the incorporation has reached about 45% at the excitation wavelength of 370 nm without any special surface modification. It is found that medium Ioadings, e.g., 5 wt% of Si NCs in encapsulating materials help to obtain high external quantum efficiency （EQE） of the mixtures of Si NCs and encapsulating materials. The curing of encapsulating materials significantly reduces EQE. Among all the encapsulating materials investigated in this work, silicone- OE6551 enables the highest EQE （21% at excitation wavelength λex = 370 nm） after curing. Based on current findings, we have discussed the continuous efforts to advance the photoluminescent application of Si NCs.

关键词： Photoluminescence Silicon nanocrystals Epoxy Silicone Quantum yield External quantum efficiency

ESR Study on the Photooxidation Mechanism of Near-Infrared Absorbing Benzothiazolone Cyanine Dye

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Chinese Chemical Letters 1997年第8期8卷 711-714页

作者： Li, j Chen, P zhao, j Zheng, DS Okasaki, T Hayami, M ACAD SINICA INST PHOTOG CHEMBEIJING 100101PEOPLES R CHINA NIPPON KANKAH SHIKISO KENKYUSHO OKAYAMA 701JAPAN

In this paper, the direct photooxidation mechanism of near-infrared absorbing benzothiazolone cyanine dye has been studied by VIS absorption spectroscopy and Electron Spin Resonance (ESR). The technique of spin trapping has been successfully applied to the detection of the photoinduced formation of singlet oxygen (O-1(2)) and superoxide (O-2(-)). It was reveled that the singlet oxygen and superoxide anion all contributed to the photofading of cyanine dye.

关键词： ESR Study on the Photooxidation Mechanism of Near-Infrared Absorbing Benzothiazolone Cyanine Dye

MODELING OF DYNAMIC RECRYSTALLIZATION OF Ti6A14V ALLOY USING A CELLULAR AUTOMATON APPROACH

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Acta Metallurgica Sinica(English Letters) 2008年第4期21卷 260-268页

作者： j.W. zhao H. Ding W.j. zhao F.R. Cao H.L. Hou Z.Q. Li School of Materials and Metallurgy Northeastern University Shenyang 110004 China Beijing Aeronautical Manufacturing Technology Research Institute Beijing 100024 China

A cellular automaton （CA） model is established to simulate dynamic recrystallization （DRX） in the β single-phase field of Ti6Al4 V alloy, and the kinetics during DRX processing has been analyzed. The model employed considers the influences of dynamic recovery, nucleation rate, strain rate and dislocation density on DRX, and practical deformation parameters, such as temperature, strain and strain rate on DRX have been considered in the simulation. The simulated DRX grain size and DRX grain shape agree well with the experimental results, which shows the availability and lea- sibility of the cellular automaton method for the simulation of DRX. The result of kinetics analysis of DRX reveals that the Avrami exponent is variable ranging from 2.4 to 2.9, which increases with the increase of strain rate.

关键词： Ti6A4 V alloyi Dynamic recrystallization Kinetics Modeling Cellular automaton

PREPARATION AND CORROSION RESISTANCE OF NiP/TiO_2 COMPOSITE FILM ON CARBON STEEL IN SULFURIC ACID SOLUTION

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Acta Metallurgica Sinica(English Letters) 2006年第2期19卷 117-123页

作者： L.Z. Song S.Z. Song j. zhao School of Environment ＆ Chemical Engineering Yanshan University Qinhuangdao 066004 China School of Materials Science and Engineering Tianjin University Tianjin 300072 China

A NiP/TiO2 composite film on carbon steel was prepared by electroless plating and sol-gel composite process. An artificial neural network was applied to optimize the prepared condition of the composite film. Corrosion behavior of the NiP/TiO2 composite film was investigated by polarization resistance measurement, anode polarization, ESEM （environmental scanning electron microscopy） and EIS （electrochemical impedance spectroscopy） measurements. Results showed that the NiP/ TiO2 composite film has a good corrosion resistance in 0.5mol/L H2SO4 solution. The element valence of the composite film was characterized by XPS （X-ray photoelectron spectroscopy） spectrum, and an anticorrosion mechanism of the composite film was discussed.

关键词： electroless plating and sol-gel composite process artificial neural network NiP/TiO2 composite film corrosion resistance