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International Journal of Minerals,metallurgy and Materials 2013年第7期20卷 684-692页

作者： Ya-jun Su Xin-hua Liu Yong-fu Wu Hai-you Huang Jian-xin Xie Key Laboratory for Advanced Materials Processing (Ministry of Education) Institute of Advanced Materials and Technology Uni- versity of Science and Technology Beijing

The steady-state temperature field of horizontal core-filling continuous casting （HCFC） for producing copper cladding aluminum rods was simulated by finite element method to investigate the effects of key processing parameters on the positions of solid-liquid interfaces （SLIs） of copper and aluminum. It is found that mandrel tube length and mean withdrawing speed have significant effects on the SLI positions of both copper and aluminum. Aluminum casting temperature （TAI）（1003-1123 K） and secondary cooling water flux （600-900 L.h-1） have little effect on the SLI of copper but cause the SLI of aluminum to move 2-4 mm. When TA1 is in a range of 1043-1123 K, the liquid aluminum can fill continuously into the pre-solidified copper tube. Based on the numerical simulation, reasonable processing parameters were determined.

关键词： metal cladding copper aluminum continuous casting interfaces computer simulation

Influence of cross correlation step length on the surface stress of thin laser cladding Fe314 alloy coatings

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International Journal of Minerals,metallurgy and Materials 2012年第6期19卷 549-554页

作者： Bin Liu Shi-yun Dong Bin-shi Xu Peng He State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology Harbin 150001 China National Key Laboratory for Remanufacturing Academy of Armored Forces Engineering Beijing 100072 China

To measure the surface stress of thin laser cladding coatings with Rayleigh waves based on the cross correlation function, this pa- per introduced the influence of cross correlation step length on the stress measurement. Flat-shaped specimens made of laser cladding Fe314 alloy coatings were performed by static tensile tests, and Rayleigh wave signals were collected during the test process with an ultrasonic pulser and receiver instrument combined with two Rayleigh wave transducers. The difference in time of flight between two signals was de- termined based on the cross correlation function. The microstructure was observed by scanning electronic microscopy. The influence of the stress on the propagation velocity of Rayleigh waves and the relationship between the difference in time of flight and tensile stress under dif- ferent cross correlation step lengths were analyzed. The inhomogeneous deformation of the coatings affects the relationship between the dif- ference in time of flight and tensile stress; the stress measurement of the coatings is nearly constant with the increase of cross correlation step length when it attains one cycle.

关键词： iron alloys metal cladding laser cladding surface stress Rayleigh waves

Suppercontinuum Generation in InP Nano Inner cladding Fibers

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Chinese Physics Letters 2010年第5期27卷 142-143页

作者：段予文张茹王瑾陈曦钟昆 School of Sciences Beijing University of Posts and Telecommunications Beijing 100876 School of Ethnic Education Beijing University of Posts and Telecommunications Beijing 100876

The InP nano inner cladding fiber is fabricated by the method of modified chemical vapor deposition. The thickness of the InP nano thin film is about 16 nm. A 20 dB supercontinuum over 100nm in the telecommunication band is generated by infecting 1550nm, 120fs, 50MHz repetition rate optical pulse into this kind of fiber. Moreover, the results indicate that the width of the supercontinuum spectra can be influenced by the fiber length and pump power. The longer fiber at higher pump power can produce broader supercontinuum spectrum.

关键词： CONTINUUM mechanics INDIUM phosphide NANOSTRUCTURED materials metal cladding MICROFABRICATION CHEMICAL vapor deposition TELECOMMUNICATION SPECTRUM analysis

Boundary coupled dual-equation numerical simulation on mass transfer in the process of laser cladding

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Chinese Optics Letters 2008年第5期6卷 356-360页

作者：黄延禄杨永强卫国强师文庆李毅斌 School of Mechanical Engineering South China University of Technology

The coupled numerical simulation on fluid flow, heat transfer, and mass transfer in the process of laser cladding is undertaken on the basis of the continuum model. In the simulation of mass transfer in the laser molten pool, the concentration distribution in the regions on different sides of the interface between cladding layer and substrate is calculated separately and coupled at the co-boundary. The non-equilibrium solute partition coefficient is obtained from equilibrium solute partition coefficient according to the Sobolev model. By using the developed software which is based on the commercial software PHOENICS 1.4, the distribution of Fe in laser molten pool in an experiment of cladding Stellite 6 on 12CrMoV is calculated. The obtained results well coincide with the experimental ones.

关键词： Computer simulation Concentration (process) Continuum mechanics Flow simulation Ketones Lasers Mass transfer metal cladding

A novel diffusion model considering curvature radius at the bonding interface in a titanium/steel explosive clad plate

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International Journal of Minerals,metallurgy and Materials 2015年第9期22卷 956-965页

作者： Hai-tao Jiang Qiang Kang Xiao-qian Yan National Engineering Research Center for Advanced Rolling Technology University of Science and Technology Beijing China Railway Materials Technologies Company Limited

This article introduces an element diffusion behavior model for a titanium/steel explosive clad plate characterized by a typical curved interface during the heat-treatment process. A series of heat-treatment experiments were conducted in the temperature range from 750℃ to 950℃, and the effects of heat-treatment parameters on the microstructural evolution and diffusion behavior were investigated by optical microscopy, scanning electron microscopy, X-ray diffraction analysis, and electron-probe microanalysis. Carbon atoms within the steel matrix were observed to diffuse toward the titanium matrix and to aggregate at the bonding interface at 850℃ or lower; in contrast, when the temperature exceeded 850℃, the mutual diffusion of Ti and Fe occurred, along with the diffusion of C atoms, resulting in the for- marion of Ti-Fe intermetallics （Fe2Ti/FeTi）. The diffusion distances of C, Ti, and Fe atoms increased with increasing heating temperature and/or holding time. On the basis of this diffusion behavior, a novel diffusion model was proposed. This model considers the effects of various factors, including the curvature radius of the curved interface, the diffusion coefficient, the heating temperature, and the holding rime. The experimental results show good agreement with the calculated values. The proposed model could clearly provide a general prediction of the elements＇ diffusion at both straight and curved interfaces.

关键词： explosive bonding metal cladding diffusion models interfaces heat treatment

Effect of continuous induction annealing on the microstructure and mechanical properties of copper-clad aluminum flat bars

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International Journal of Minerals,metallurgy and Materials 2016年第12期23卷 1427-1436页

作者： Xin-hua Liu Yan-bin Jiang Hong-jie Zhang Jian-xin Xie Key Laboratory for Advanced Materials Processing of the Ministry of Education University of Science and Technology Beijing Institute of Advanced Materials and Technology University of Science and Technology Beijing

Copper-clad aluminum （CCA） flat bars produced by the continuous casting-rolling process were subjected to continuous induction heating annealing （CIHA）, and the effects of induction heating temperature and holding time on the microstructure, interface, and mechanical properties of the fiat bars were investigated. The results showed that complete recrystallization of the copper sheath occurred under CIHA at 460℃ for 5 s, 480℃ for 3 s, or 500℃ for 1 s and that the average grain size in the copper sheath was approximately 10.0 μm. In the case of specimens subjected to CIHA at 460-500℃ for longer than 1 s, complete recrystallization occurred in the aluminum core. In the case of CIHA at 460-500℃ for 1-5 s, a continuous interracial layer with a thickness of 2.5-5.5 μm formed and the thickness mainly increased with increasing annealing temperature. After CIHA, the interracial layer consisted primarily of a Cu9A14 layer and a CuA12 layer; the average interface shear strength of the CCA flat bars treated by CIHA at 460-500℃ for 1-5 s was 45-52 MPa. After full softening annealing, the hardness values of the copper sheath and the aluminum core were HV 65 and HV 24, respectively, and the hardness along the cross section of the CCA flat bar was uniform.

关键词： metal cladding copper-clad aluminum annealing interfaces mechanical properties

In-situ synthesis of Fe-Mn-Si-Cr-Ni shape memory alloy functional coating by laser cladding

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Chinese Optics Letters 2014年第4期12卷 48-50页

作者：徐鹏鞠恒林成新周超玉潘德位 Transportation Equipment and Ocean Engineering College Dalian Maritime University

Fe-Mn-Si-Cr-Ni composite powders are utilized to form a functional shape memory alloy cladding layer （SMACL） using a laser cladding method. The microstructure, microhardness, and phase composition of the SMACL are measured, and the extent of deformation of the laser cladding samples is determined. The SMACL is composed of planar, cellular, and dendritic crystals, equiaxed grains, and oxides with increasing distance from the substrate surface. The SMACL is further composed of ε-martensite and γ-austenite phases, while the tempered SMACL consists mainly of γ-austenite. Extensive deformation occurs in AISI 304 stainless steel laser cladding samples. By contrast, limited deformation is observed in the SMACL samples.

关键词： Austenite Laser cladding Manganese metal cladding Nickel Protective coatings Shape memory effect Silicon

Ag-coated Long-period Fiber Grating

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Semiconductor Photonics and Technology 2005年第3期11卷 203-207,211页

作者： GU Zheng-tian XU Yan-ping CHEN Jia-bi Lab. of Photo-electric Function. Films College of Sci. Shanghai University of Science and Technology Shanghai 200093 CHN

Based on coupled-mode theo ry , the eigenvalue equation of five-layered long-period fiber grating(LPFG) sens or with Ag film and gas-sensitive film overlays are firstly studied. The probl em of resolving complex eigenvalue equation on five-layered LPFG is analyzed, a nd the method of resolution is also given. Then the eigenvalue equation of three -layered metal cladding LPFG is analyzed, and the complex transcendental equati on is also discussed. The computing result shows that the coupling between the l ow-order EH modes and the core mode is much stronger than that between the low -order HE modes and the core mode.

关键词： Long-period fiber grating Gas sensors metal cladding Complex eigenvalue equation