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Acta Metallurgica Sinica(English Letters) 1996年第6期9卷 443-452页

作者： z.Q. hu w.R.Sun and S.R. Guo(Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110015, China

The effects of the trace elements, P, S and Si,on the solidification, segregation,microstructure and mechanical properties of GH761 and In718 alloys were *** was found that the segregation of the P,S and Si can be greatly aggravated or relieved by the precipitation taking place during the solidification. In the heat treated state,P enhances the intergranular precipitation in the GH761 *** refinement of P in In718 alloy causes the appearance of a film-like δ*** increases the intergranular precipitation of the M_6C and the Laves Phase in the In718 alloy.P, S and Si play diverse roles in the tensile and the stress rupture properties of the GH761 and In718 alloys. The most striking effect is that P significantly prolongs the stress rupture lives of the GH761 and In718 alloys in a wide range of 0.00050.015 wt% .The mechanisms by which P,S and Si influence the superalloys are discussed in the text.

关键词： superalloy,segregation microstructure mechanical property

Five-fold local symmetry in metallic liquids and glasses

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Chinese Physics B 2017年第1期26卷 10-19页

作者： M z Li H L Peng Y C hu F X Li H P zhang w H wang Department of Physics Beijing Key Laboratory of Opto-electronic Functional Materials ＆ Micro-nano Devices Renmin University of China Beijing 100872 China Institute of Physics Chinese Academy of Sciences Beijing 100091 China

The structure of metallic glasses has been a long-standing mystery. Owing to the disordered nature of atomic structures in metallic glasses, it is a great challenge to find a simple structural description, such as periodicity for crystals, for establishing the structure–property relationship in amorphous materials. In this paper, we briefly review the recent developments of the five-fold local symmetry in metallic liquids and glasses and the understanding of the structure–property relationship based on this parameter. Experimental evidence demonstrates that five-fold local symmetry is found to be general in metallic liquids and glasses. Comprehensive molecular dynamics simulations show that the temperature evolution of five-fold local symmetry reflects the structural evolution in glass transition in cooling process, and the structure–property relationship such as relaxation dynamics, dynamic crossover phenomena, glass transition, and mechanical deformation in metallic liquids and glasses can be well understood base on the simple and general structure parameter of five-fold local symmetry.

关键词： metallic glass structure–property relation five-fold local symmetry

Synthesis and Characterization of Fe_(50)Cr_(14)Mo_(14)C_(14)B_6Gd_2 Bulk Amorphous Steel

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Journal of Materials Science & Technology 2010年第9期26卷 783-786页

作者： M. Iqbal J.I. Akhter H.F. zhang z.Q. hu Physics Division Pakistan Institute of Nuclear Science &: Technology P.O. Nilore Islamabad Pakistan Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of SciencesShenyang 110016 China

Bulk amorphous steel having 7 mm thickness was synthesized to evaluate its thermal stability and mechanical *** steel was synthesized by Cu mold casting technique using 1-2N pure *** of the material was done by X-ray diffraction,differential scanning calorimetry and scanning electron *** activation energies were calculated by Kissinger equation and it was found that the steel had better stability against *** properties like Vicker s hardness,nanohardness,elastic modulus and elastic recovery of as-cast and annealed samples were *** was concluded that the present steel had good glass-forming ability（GFA） and mechanical properties.

关键词： Bulk amorphous steels Activation energy Glass-forming ability Mechanical properties

Polydopamine wrapped polyaniline nanosheets:Synthesis and anticorrosion application for waterborne epoxy coatings

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Journal of Materials Science & Technology 2024年第9期176卷 155-166页

作者： X.P.hu Y.H.zhang C.B.Liu H.z.Cui School of Materials Science and Engineering Shandong University of Science and TechnologyQingdao 266590China School of Materials Science and Engineering Ocean University of ChinaQingdao 266100China

Two-dimensional materials have been proved to be effective in improving the performance of anticorrosive ***,most of the reported two-dimensional materials only have the ability to passively block corrosive media and cannot effectively inhibit localized corrosion reactions at the metal/coating ***,we first synthesized a novel polyaniline(PANI)nanosheet with both barrier and passivation functions for *** addition,polydopamine(PDA)wrapped PANI nanosheets(PANI@PDA)were obtained by in situ self-polymerization reaction of dopamine on the PANI surface,which enhance its interfacial interaction with polymeric *** chemical structure,morphology and corrosion inhibition properties of the nanosheets were systematically *** incorporated PANI@PDA nanosheets in composite coating provide a longer penetration path for corrosive ***,the uniformly dispersed two-dimensional nanosheets induce the formation of passivation film on the metal *** protective effect of PANI@PDA nanosheets on coatings was verified by electrochemical impedance spectroscopy(EIS).Results indicated that the prepared composite coating exhibited excellent corrosion resistance throughout the test *** simple and effective modification strategy based on conductive polymers provides a new insight into the development of environmentally adaptive composite coatings with active and passive protection.

关键词： Corrosion prevention Polyaniline Polydopamine Nanosheet Active protection

STUDY ON TEMPERATURE FIELD INDUCED IN HIGH FREQUENCY INDUCTION HEATING

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Acta Metallurgica Sinica(English Letters) 2006年第3期19卷 190-196页

作者： H. Shen z.Q. Yao Y.J. Shi J. hu School of Mechanical Engineering Shanghai Jiaotong University Shanghai 200030 China

A mathematical model was established for the temperature field developed during high frequency induction heating （HFIH） by Maxwell＇s equations. It required solving the coupled equations of the electromagnetic and temperature fields. The numerical simudation was performed using FEMLAB. The comparison of the calculations using the proposed model with experimental results showed a very good correlation. The effects of the heating parameters in high frequency induction such as the distance between the plate and the coil, the applied current, the frequency, and the turns of the coil on the temperature profiles developed in the plate were also discussed using the established model.

关键词： high frequency induction temperature field numerical simudation

NUMERICAL INVESTIGATION OF STRAIGHT-LINE LASER FORMING UNDER THE TEMPERATURE GRADIENT MECHANISM

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Acta Metallurgica Sinica(English Letters) 2006年第2期19卷 144-150页

作者： Y.J. Shi H. Shen z.Q. Yao J. hu School of Mechanical and Power Engineering Shanghai Jiaotong University Shanghai 200030 China

Laser forraing is a new flexible and dieless forming technique. To achieve the high accuracy forming, the temperature gradient mechanism （TGM） is studied. In the analysis of TGM, the plate bends about x-axis and about y-axis as well. To understand the deformation trend, the numerical simulation of deformation of plate is conducted by choosing different laser powers, laser spot diameters, scanning speeds, lengths, widths and thicknesses. From the results of simulation, it can be seen that the laser spot diameter, the scanning speed, laser power and thickness of plate play dominant roles in the laser forming process. However, the bending angles αx and αy show different trends with the variation of parameters. In addition, in comparison with above four parameters, the effect of length and width of plate on the beading angle may be neglected, but their effects are significant for the bending radius R.

关键词： laser forming temperature gradient mechanism metal plate

Simulation of wave-Flow-Cavitation Interaction Using a Compressible Homogenous Flow Method

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Communications in Computational Physics 2013年第7期14卷 328-354页

作者： J.G.zheng B.C.Khoo z.M.hu Department of Mechanical Engineering National University of SingaporeSingapore 119260 Singapore-MIT Alliance National University of SingaporeSingapore 117576 Temasek Laboratories National University of SingaporeSingapore 117411

A numerical method based on a homogeneous single-phase flow model is presented to simulate the interaction between pressure wave and flow *** account for compressibility effects of liquid water,cavitating flow is assumed to be compressible and governed by time-dependent Euler equations with proper equation of state(EOS).The isentropic one-fluid formulation is employed to model the cavitation inception and evolution,while pure liquid phase is modeled by Tait equation of *** of large stiffness of Tait EOS and great variation of sound speed in flow field,some of conventional compressible gasdynamics solvers are unstable and even not applicable when extended to calculation of flow *** overcome the difficulties,a Godunov-type,cell-centered finite volume method is generalized to numerically integrate the governing equations on triangular *** boundary is treated specially to ensure stability of the *** method proves to be stable,robust,accurate,time-efficient and *** numerical experiments are designed to investigate unsteady dynamics of the cavitating flow impacted by pressure wave,which is of great interest in engineering applications but has not been studied systematically so *** simulation indicates that cavity over cylinder can be induced to collapse if the object is accelerated suddenly and extremely high pressure pulse results almost ***,however,may be avoided by changing the traveling speed *** accompanying huge pressure increasemay damage underwater ***,cavity formed at relatively high upstream speed may be less distorted or affected by shock wave and can recover fully from the initial *** is observed that the cavitating flow starting from a higher freestream velocity is more stable and more resilient with respect to perturbation than the flow with lower background *** findings may shed some light on how to control cavitation development

关键词： Cavitating flow isentropic cavitation model shock-flow-cavitation interaction

Fatigue Properties Improvement of Low-Carbon Alloy Axle Steel by Induction Hardening and Shot Peening:A Prospective Comparison

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Acta Metallurgica Sinica(English Letters) 2022年第8期35卷 1343-1356页

作者： G.C.Chu F.z.hu X.J.jin Y.zhang Q.wang J.P.Hou z.F.zhang Shi-Changxu Innovation Center for Advanced Material Institute of Metal ResearchChinese Academy of SciencesShenyang 110016.China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China Manshan Iron and Steel Co. Ltd.Maanshan 243000China School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Baowu Group Masteel Rail Transit Materials Technology Company Limited Maanshan 243000China

Fatigue fracture is the major threat to the railway axle, which can be avoided or delayed by surface strengthening. In this study, a low-carbon alloy axle steel with two states was treated by surface induction hardening and shot peening, respectively, to reveal the mechanism of fatigue property improvement by microstructure characterization, microhardness measurement, residual stress analysis, roughness measurement, and rotary bending fatigue tests. The results indicate that both quenching and tempering treatment can effectively improve the fatigue properties of the modified axle steel. In addition, induction hardening can create an ideal hardened layer on the sample surface by phase transformation from the microstructure of ferrite and pearlite to martensite. By comparison, shot peening can modify the microstructure in surface layer by surface severe plastic deformation introducing a large number of dislocation and even cause grain refinement. Both induction hardening and shot peening create compressive residual stress into the surface layer of axle steel sample, which can effectively reduce the stress level applied to the metal surface during the rotary bending fatigue tests. On the whole, the contribution of induction hardening to the fatigue life of axle steel sample is better than that of the shot peening, and induction hardening shows obvious advantages in improving the fatigue life of axle steel.

关键词： Surface strengthening Induction hardening Shot peening Axle steel Fatigue property improvement

STUDY ON THE FINITE ELEMENT NUMERICAL SIMULATION OF SHEET METAL FORMING

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Acta Metallurgica Sinica(English Letters) 2004年第3期17卷 299-302页

作者： J.L.Song D.J.hu z.L.Chang T.Y.Li z.B.Jiang School of Mechanical Engineering Shanghai Jiaotong University Shanghai 200030 China Department of Materials Engineering Taiyuan Heavy Machinery Institute Taiyuan 030024 China

Based on the Finite Element Theory of Rigid Plastic,relevant problems during plas-tic simulation on sheet metal forming were technologically studied and simplified;a simplified model of the blank holder during the drawing process was established and the effects of related parameters on the forming processes were also *** the same time,a finite--element numerical simulation program SPID was *** distribution of strain and relationship of stress--stroke simulated were compared with experimented,the results are well coincided with each *** is verified that the analytical program is reliable.

关键词： sheet metal forming finite-element numerical simulation

EXPERIMENTAL RESEARCH AND NUMERICAL SIMULATION OF LASER SHOCK FORMING OF TA2 TITANIUM SHEET

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Acta Metallurgica Sinica(English Letters) 2006年第5期19卷 347-354页

作者： F. wang z. Q. Yao J. hu Q.L. Deng School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200030 China

Laser shock forming （ISF） was a new technique realized by applying an impulsive pressure generated by laser-induced shock wave on the surface of metal sheet. LSF of metal sheet was investigated with experiments and numerical simulation. The basic theories were introduced; the surface quality and deformation of the processed titanium sample （TA2） were examined; ABAQUS was used to simulate ISF and the central displacement of the shocked region was measured and compared with the simulation. Overlapped ISF treatment was experimentally carried out to produce groove and simulation. The results showed that the surface quality and the microstructure with single laser pulse had no remarkable change, and ablation was observed on the surface of the sample with overlapped pulses. The deformation observed in the numerical simulation agreeed with that observed in the experimental measurement quite well.

关键词： laser shock forming numerical simulation surface quality deformation