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CALCULATION OF THE DAMPIng OF THE Zn-27Al ALLOy BASED ON THE MICRO INTERFACE SLIDIng MODEL

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Acta Metallurgica Sinica(English Letters) 2006年第3期19卷 228-234页

作者： y.Z. Zhao q. Gao y.C. Liu School of Civil Engineering Southwest Jiaotong University Chengdu 610031 China Department of Applied Mechanics and Engineering Southwest Jiaotong University Chengdu 610031 China

The microstructures of the Zn-27Al alloy after modification, solid-solution treatment, and natural aging were studied. It was clarified why the damping properties of Zn-27Al alloys, after treatment, had advanced most on the basis of analyzing the microstructures. Approximate expressions have been educed, which can be used to q.antificationally work out the damping of the Zn-27Al alloy on the basis of the micro interface sliding model. By comparing the testing damping properties of the foundry Zn-27Al alloys and the Zn-27Al alloys after modification, solid solution, and natural aging, it was shown that the expressions were rational.

关键词： modification solid solution and aging damping micromechanism micro interface sliding model

Template-free Fabrication and Luminescent Characterization of Highly Uniform and Monodisperse y_2O_2S:Sm^(3+) Hollow Submicrospheres

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Journal of Materials Science & Technology 2012年第7期28卷 666-672页

作者： S.q. Deng Z.P. Xue y.H. y.ng q. y.ng y.L. Liu Department of Chemistry Jinan University Guangzhou 510632 China

Well dispersed and homogeneous y2O2S：Sm3＋ hollow submicrospheres were successfully achieved by a template- free solvothermal method combining with a postcalcining process. The crystalstructure and particle morphology were investigated by the X-ray diffraction （XRD）, Fourier transform infrared （FT-IR） spectra, scanning and transmission electron microscopy （SEM and TEM）, respectively. A possible growth mechanism was proposed to reveal the formation process. Luminescence properties of the y202S：Sm3＋ long-lasting phosphor were an- alyzed by measuring the excitation spectra, emission spectra, afterglow decay curve and thermoluminescence curve. The excitation spectra indicated that the phosphor could be excited effectively by the ultraviolet-light emitting diode （UV-LED） or blue LED, and the emission spectra showed that the phosphor could emit red light from 600 to 650 nm.

关键词： yttrium oxysulfide Hollow submicrosphere Luminescence Long-lasting phosphor

Exploitation of Fenton and Fenton-like reagents as alternative conditioners for alum sludge conditioning

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Journal of Environmental Sciences 2009年第1期21卷 101-105页

作者： Maha A. Tony y. q. Zhao Aghareed M. Tayeb Centre for Water Resources Research School of Architecture Landscape and Civil Engineering University College Dublin Newstead Belfield Dublin 4 Ireland. Basic Science of Engineering Department Faculty of Engineering Minoufiya University Minoufiya 32511 Egypt Chemical Engineering Department Faculty of Engineering Minia University Minia 61111 Egypt

The use of Fenton＇s reagent （Fe^2＋/H2O2） and Fenton-like reagents containing transition metals of Cu（Ⅱ）, Zn（Ⅱ）, Co（Ⅱ）, and Mn（Ⅱ） for an alum sludge conditioning to improve its dewaterability was investigated. The results obtained were compared with those obtained from conditioning the same alum sludge using cationic and anionic polymers. Experimental results show that Fenton＇s reagent was the best among the Fenton and Fenton-like reagents for the alum sludge conditioning. A considerable effectiveness of capillary suction time （CST） reduction efficiency of 47% can be achieved under test conditions of Fe^2＋/H2O2 = 20/125 mg/g DS （dry solid） and pH 6.0. The observation of floc-like particles after Fenton＇s reagent conditioning of alum sludge suggested that the mechanism of Fenton＇s reagent conditioning was different from that of polymer conditioning. In spite of the lower efficiency in the CST reduction of Fenton＇s reagent in alum sludge conditioning compared to that of polymer conditioning, Fenton＇s reagent offers a more environmentally safe option. Tiffs study provided an example of proactive treatment engineering, which is aimed at seeking a safe alternative to the use of polymers in sludge conditioning towards achieving a more sustainable sludge management strategy.

关键词： alum sludge conditioning Fenton and Fenton-like reagents organic polymers cost estimate

Plasma enhanced diamond deposition on steel and Si substrates

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Acta Metallurgica Sinica(English Letters) 2009年第5期22卷 321-329页

作者： y.S. Li y. Tang Wo Chen q. y.ng C.Xiao A. Hirose Plasma Physics Laboratory University of Saskatchewan Saskatoon SK S7N 5E2 Canada Department of Mechanical Engineering University of Saskatchewan Saskatoon S7N 5A9 Canada

Diamond growth on Fe-Cr-Al-Si steel and Si substrates was comparatively investigated in microwave plasma enhanced chemical vapor deposition （MPCVD） reactor with different deposition parameters. Adherent nanocrystalline diamond films were directly deposited on this steel substrate under a typical deposition condition, whereas microcrystalline diamond films were produced on Si wafer. With increasing CH4 concentration, reaction pressure, or the total gas flow rate, the q.ality of nanocrystalline diamond films formed on Fe-Cr-Al-Si substrates is gradually deteriorated in terms of density and adhesion. This impaired diamond q.ality on steels is primarily associated with a combined effect by the substrate composition and the specific process conditions that favor excessive nucleation of diamond.

关键词： Plasma CVD Diamond film Steel Si

Investigation of the crack problem in non-local piezoelectric materials under combined electromechanical loadings

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Acta Mechanica Sinica 2009年第2期25卷 219-225页

作者： q. Li y. Chen School of Aerospace, Xi’an Jiao-Tong University,710049 Xi’an, China School of Aerospace Xi’an Jiao-Tong University Xi’an China

The present investigation of the crack problem in piezoelectric materials is performed based on the non-local theory. After some manipulations, the impermeable crack, the permeable crack （the crack gap is full of NaCI solution）, and the semi-permeable crack （the crack gap is full of air or silicon oil） are reduced to a uniform formulation by assuming the normal electric displacement on the crack surfaces to be an unknown variable. Thus, a triple integral eq.ation with the unknown normal electric displacement is established. By using the Newton iterative method and solving the triple integral eq.ation, it is found that the normal electric displacement on the crack surfaces is no longer a constant as determined by previous studies, rather, it depends upon the remote combined electromechanical loadings. Numerical results of the stresses and electric displacement fields show that there are no singularities at the crack tips so that the stresses remain finite. It is of great significance that the concrete electric boundary condition on the crack surfaces exerts significant influence on the near-tip fields and in this way plays an important role in evaluating the crack stability in the non-local piezoelectric materials. More specifically, the impermeable crack model always overestimates the finite stresses at the crack tips, whereas the permeable crack model always underestimates them.

关键词： Crack Non-local piezoelectric materialsImpermeable Permeable Semi-permeable

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 obliq.e).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

A NEURAL NETWORK FOR WELD PENETRATION CONTROL IN GAS TUngSTEN ARC WELDIng

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Acta Metallurgica Sinica(English Letters) 2006年第1期19卷 27-33页

作者： C.S. Wu J. q. Gao y.H. Zhao Institute of Materials Joining Shandong University Jinan 250061 China

Realizing of weld penetration control in gas tungsten arc welding req.ires establishment of a model describing the relationship between the front-side geometrical parameters of weld pool and the back-side weld width with sufficient accuracy. A neural network model is developed to attain this aim. Welding experiments are conducted to obtain the training data set （including 973 groups of geometrical parameters of the weld pool and back-side weld width） and the verify.ng data set （108 groups）. Two data sets are used for training and verify.ng the neural network, respectively. The testing results show that the model has sufficient accuracy and can meet the req.irements of weld penetration control.

关键词： neural network weld penetration control back-side weld width,gas tungsten arc welding

DEFORMATION BEHAVIOR OF AA6063 ALUMINIUM ALLOy AFTER REMOVIng FRICTION EFFECT UNDER HOT WORKIng CONDITIONS

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Acta Metallurgica Sinica(English Letters) 2008年第6期21卷 451-458页

作者： Z. y. Chen S. q. Xu X.H. Dong National Die ＆ Mold CAD Engineering Research Center Shanghai Jiaotong University Shanghai 200030 China College of Materials Science and Engineering Taiyuan University of Technology Taiyuan 030024 China

The hot deformation behavior of AA6063 aluminium alloy has been investigated by means of compression tests at temperatures between 400 and 520℃, and strain rates ranging from 2.5 to 10 s^-1. Owing to the barreling, the theoretical model on the basis of Hills general method is used to calculate the flow stress of a cylindrical specimen under uniaxial simple compression so as to consider the friction effect at the die-specimen interface. A method of evaluating the friction coefficient by combining compression tests with the finite element method is presented. The real flow behavior of AA6063 aluminium alloy can be described with sinh-Arrhenius eq.ation. The hot deformation activation energy q.derived from the corrected stress and strain data is 232. 350 kJ/mol.

关键词： Barreling Compression test Friction Flow stress Aluminium alloy Activation energy

An in-vitro Investigation of Iron-Containing Hydroxyapatite/Titanium Composites

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Journal of Materials Science & Technology 2011年第6期27卷 546-552页

作者： q. Chang H.q. Ru D.L. Chen X.y. yue L. yu C.P. Zhang Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education) Northeastern University Shenyang 110004 China Department of Mechanical and Industrial Engineering Ryerson University 350 Victoria Street Toronto Ontario M5B 2K3 Canada

The in-vitro biological behavior of a newly-developed iron-containing hydroxyapatite/titanium（HA/Ti） composite was investigated by immersing the composites in the simulated body fluid（SBF） for up to 5 *** addition of iron was observed to have a significant influence on the in-vitro biological behavior of the *** obtained results revealed that the stability of the composites in the physiological solution was markedly *** solubility decreased in the order of pure HA,HA/5（Ti-33Fe）,and HA/15（Ti33Fe）.Precipitation occurred on the surface of HA/5（Ti-33Fe） composite,showing a good combination of physiostability with bioactivity,while HA/15（Ti-33Fe） composite exhibited superior physiostability since there was no obvious change on the surface of HA/15（Ti-33Fe）.

关键词： Hydroxyapatite composite Iron Titanium Simulated body fluid Biological behavior