Started in 1985 Semimonthly
ISSN 1005-0302
CN 21-1315/TG
Impact factor:6.155

The journal has been awarded the excellent periodical in China, and its articles are covered by SCI, EI, CA, SA, JST, RJ, CSA, MA, EMA, AIA etc., PASCAL web. ISI web of Science,SCOPUS.

  Current Issue
      28 May 2001, Volume 17 Issue 03 Previous Issue    Next Issue
    For Selected: View Abstracts Toggle Thumbnails
    Research Articles
    Preparation, characterization and luminescent properties of MCM-41 type materials impregnated with rare earth complex
    Lianshe FU, Hongjie ZHANG, Philippe Boutinaud
    J. Mater. Sci. Technol., 2001, 17 (03): 293-298. 
    Abstract   HTML   PDF (107KB)
    Hybrid materials incorporating Eu-(TTA)(3). 2H(2)O (7hereafter designated as Eu-TTA, with TTA: thenoyltrifluoroacetone) in unmodified or modified MCM-41 by 3-aminopropyl-triethoxysilane (APTES) were prepared by impregnation method. The obtained materials were characterized using X-ray diffraction (XRD), IR and diffuse reflectance spectroscopy and luminescence spectra. All the hybrid samples exhibited the characteristic emission bands of EU3+ under UV light excitation at room temperature, and the excitation spectra showed significant blue-shifts compared to the pure rare-earth complex. Although the red emission intensity in the modified hybrid was almost the half of the red emission intensity in the pure Eu-TTA complex at room temperature, the hybrid showed a much higher thermal stability due to the shielding character of the MCM-41 host.
    References | Related Articles | Metrics
    Characteristics of S/L interface evolution during high rate directional solidification
    Hengzhi FU, Xingguo GENG
    J. Mater. Sci. Technol., 2001, 17 (03): 299-302. 
    Abstract   HTML   PDF (203KB)
    The present paper aims to the characterization of high rate direction solidification on AI-Mn and AI-Cu alloys. It is indicated that the relevant cooling rate of high rate directional solidification is defined within 10(0)~10(3) K/s that is located in the region between near-equilibrium slow growth rate and rapid solidification rate beyond equilibrium condition, and at the meantime there occurred a series of turning effect of interface stability and morphologies. With the increase of growth velocity the interface with planar front evolved to cells and dendrites at the stage of near-equilibrium and with further increase of growth rate they transformed reversely from dendrites to cell structure and then to absolute stability of planar interface. An explanation based on effective constitutional supercooling about the evolution of interface morphologies with the change of growth rate was proposed.
    References | Related Articles | Metrics
    Nanomechanics of fiber-like nanomaterials
    Z.L.Wang
    J. Mater. Sci. Technol., 2001, 17 (03): 303-305. 
    Abstract   HTML   PDF (464KB)
    Property characterization of nanomaterials is challenged by the small size of the structure because of the difficulties in manipulation. Here we demonstrate a novel approach that allows a direct measurement of the mechanical properties of individual nanotube-like structures by in-situ transmission electron microscopy (TEM). The technique is powerful in a way that it can directly correlate the atomic-scale microstructure of the carbon nanotube with its physical properties, providing a one-to-one correspondence in structure-property characterization. Applications of the technique will be demonstrated on mechanical properties, the electron field emission and the ballistic quantum conductance in individual nanotubes.
    References | Related Articles | Metrics
    Electromagnetic filteration of primary Fe-rich phases from AI-Si alloy melt
    Zhenming XU, Tianxiao LI, Da SHU, Yaohe ZHOU
    J. Mater. Sci. Technol., 2001, 17 (03): 306-310. 
    Abstract   HTML   PDF (552KB)
    Electromagnetic filtration primary Fe-rich phases (complex compound of AlFeSiMn) from Al-Si alloy melt containing 1.2 wt pet Fe have been studied by theoretical analysis and on a self-designed electromagnetic filtration equipment. The principle of the electromagnetic filtration is that the EMF (electromagnetic force) scarcely acts on the primary Fe-rich phases having low electric conductivity, which are then moved in the direction opposite to that of the EMF. Experimental results show that the primary Fe-rich phases are separated from AI-Si alloy melt and are collected in the filter while the melt is in horizontal flow. The removal efficiency of the primary iron-phases (eta) calculated is less as the greatest flow velocity of the melt (u(M)) and the height of the filter (2h) are larger, while it becomes larger as EMF, operating distance of electromagnetic force (x) and particle size (d(p)) become larger. It has been confirmed that the primary iron-phases larger than 20 mum can be removed efficiently by theoretical analysis and experiments. This new technique is high efficient and available for continuously flowing melts as compared with natural settling and filtration methods, which offer a Possibility for recycling high quality aluminum alloys.
    References | Related Articles | Metrics
    Initial magnetization curve and hardening mechanism in the nanocomposite Nd8Fe85Nb1B6 ribbon
    Y, ong GAO, Shaoqing ZHANG, Bocao LIU
    J. Mater. Sci. Technol., 2001, 17 (03): 311-314. 
    Abstract   HTML   PDF (134KB)
    The melt-spun Nd8Fe85Nb1B6 ribbon was prepared by the single roller method with the tangential speed of 20 m/s. A mixture of Nd2Fe14B and alpha -Fe phases with the average crystalline grain size of about 20 nm was found to exist in the as-quenched ribbons. The initial magnetization curve of the nanocomposite Nd8Fe85Nb1B6 ribbon can be divided into four sections by the inflection points on it. The magnetically hardening mechanism corresponding to each section was investigated. The initial susceptibility of the Nd8Fe85Nb1B6 ribbon is higher than that of the Nd15Fe85B9 powder, which may be attributed to the reversible magnetization rotation in the central region not influenced by the exchange-coupling effect within the alpha -Fe grains. The above-mentioned magnetization rotation leads to the formation of equilibrium 180 deg. domain walls at the boundaries of the alpha -Fe grains. With the increase of applied field, these domain walls are compressed reversibly towards the Nd2Fe14B grains and eventually invade into them. The irreversible movement of the domain walls in the Nd2Fe14B grains accounts for the steepest growth of magnetization with the applied field. Finally, the magnetically inhomogeneous "core regions" are formed in the Nd2Fe14B grains, and the magnetization rotation in these "core regions" indicates the end of the whole initial saturation process.
    References | Related Articles | Metrics
    Precipitation of α(2) phase in α+βsolution-treated and air-cooled Ti-Al-Sn-Zr-Mo-Si-Nd alloys
    Jun ZHANG, Dong LI
    J. Mater. Sci. Technol., 2001, 17 (03): 315-317. 
    Abstract   HTML   PDF (356KB)
    A series of Ti-Al-Sn-Zr-Mo-Si-Nd alloys with various content of Al were solution treated in alpha+beta phase field and air-cooled. The precipitation of α(2) phase in cooling was investigated by transmission electron microscopic analysis. The precipitation characteristic of α(2) phase was discussed. The precipitation of α(2) phase would proceed by the nucleation and growth of α(2) phase dependent on the diffusion of Al atoms. And a comparison on the difference of precipitation of α(2) phase was carried out under the conditions of air-cooling and quenching in water. The investigation showed that the air-cooling and even quenching could supply enough time for the precipitation and growth of α(2) phase when Al content reached a certain value even though far away from the stoichiometric composition of Ti3Al.
    References | Related Articles | Metrics
    Effect of pre-strain on the transformation and recovery behaviours of a Ti44Ni47Nb9 shape memory alloy
    Wei JIN, Mingzhou GAO, Rui YANG, Zhuangqi HU
    J. Mater. Sci. Technol., 2001, 17 (03): 318-320. 
    Abstract   HTML   PDF (96KB)
    The recovery strain, stress and transformation temperature of different pre-strained specimens of Ti44Ni47Nb9 were investigated by tensile test and electrical resistance measurement. The results indicated that pre-strain increases the reverse martensitic transformation temperature (A ' (s)) and hysteresis (A(s) - M-s). The recovery strain and stress are higher if the specimens are pre-strained between M-s and A(s) temperature than outside this temperature range. There exists an optimal pre-strain value, about 10%, at which the specimen exhibits maximum recovery strain and stress.
    References | Related Articles | Metrics
    State of the art and perspectives of hydroforming of tubes and sheets
    F. Vollertsen
    J. Mater. Sci. Technol., 2001, 17 (03): 321-324. 
    Abstract   HTML   PDF (145KB)
    Hollow parts of high accuracy and high strength can be produced by forming methods using liquid media. Hydroforming of tubes has reached a high standard for small parts (volume some 1000 cm(3)) and is further developed for larger parts (volume some 10.000 cm(3)). Processes for hydraulic sheet metal forming are sometimes used for small parts from single sheets. These processes are currently under intensive investigation, which is also true for the processing of double layered sheets. Single,sheets can be formed using membranes which separate the workpiece and the liquid. This results in interesting possibilities for a part and process integration in one step. The forming performance of aluminum alloys can be enhanced by using a heated liquid media when forming without membranes.
    References | Related Articles | Metrics
    High temperature deformation of Al2O3/Cu composites
    Jianjun WU. Yun ZHANG, Yanfei JIANG, Meiyun XUE, Tingquan LEI
    J. Mater. Sci. Technol., 2001, 17 (03): 325-328. 
    Abstract   HTML   PDF (151KB)
    This work concerns with the high temperature deformation of internally oxidized Al2O3/Cu composites. The investigation revealed that dispersive alumina can obstruct dislocation sliding and define the subgrain size thereby improve significantly the strength of the materials at high temperature. The sliding of dislocations is a main deformation mechanism in the given temperature range. The sliding of grain boundary and diffusive creep play important roles at high temperature and low strain rate. The dispersoids can raise the recrystallization temperature to higher than 1223 K. Dynamic recovery is a main softening way under the experimental conditions. Higher deformation rate and lower deformation temperature imply a higher flow stress.
    References | Related Articles | Metrics
    Three-dimensional rigid-plastic FEM simulation of bulk forming processes with new contact and remeshing techniques
    Debin Shan, Youngsuk Kim, Hyunsoo Kim
    J. Mater. Sci. Technol., 2001, 17 (03): 329-332. 
    Abstract   HTML   PDF (152KB)
    Some techniques such as die surface description, contact judgement algorithm and remeshing are proposed to improve the robustness of the numerical solution. Based on these techniques, a three-dimensional rigid-plastic FEM code has been developed. Isothermal forging process of a cylindrical housing has been simulated. The simulation results show that the given techniques and the FEM code are reasonable and feasible for three-dimensional bulk forming processes.
    References | Related Articles | Metrics
    Computer simulation and X-ray diffraction of nanocrystals
    Ming CHANG, Baohe YANG, Xiaolu XI, Hao CHANG
    J. Mater. Sci. Technol., 2001, 17 (03): 333-337. 
    Abstract   HTML   PDF (186KB)
    X-ray diffraction of structure in nanocrystalline alpha -Fe and Cu was studied by atomistic simulation. Atomic position equilibrium was reached by using molecular dynamics method to simulate nanocrystalline structure with Finnis potentials to model interatomic interactions. It was found that the boundary component exhibits short-range order, and the distortion in crystalline component increases with the decrease of grain size.
    References | Related Articles | Metrics
    Microstructure in the weld metal of austenitic-pearlitic dissimilar steels and diffusion of element in the fusion zone
    Yajiang LI, Zengda ZOU, Bing ZHOU
    J. Mater. Sci. Technol., 2001, 17 (03): 338-342. 
    Abstract   HTML   PDF (284KB)
    Microstructure and alloy element distribution in the welded joint between austenitic stainless steel (1Cr18Ni9Ti) and pearlitic heat-resistant steel (1Cr5Mo) were researched by means of light microscopy, scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). Microstructure, divisions of the fusion zone and elemental diffusion distributions in the welded joints were investigated. Furthermore, solidification microstructure and S-ferrite distribution in the weld metal of these steels are also discussed.
    References | Related Articles | Metrics
    Two hypotheses of "melanization" on electrogalvanized steel surface
    Ning LT, Derui ZHOU, Deyu LI, Kurachi Mitsuo
    J. Mater. Sci. Technol., 2001, 17 (03): 343-345. 
    Abstract   HTML   PDF (80KB)
    Melanization is harmful to the lightness of galvanized steel surface and also reduces the bonding force between a paint coat and the steel sheet. Experimental results showed that the hypothesis of Zn-Pb codeposition does not hold true, while the fact that PbSO4 micelles in sulfate bath settle on the coating surface support the second hypothesis. The authors come to the conclusions that (1) Any measure to eliminate PbSO4 micelles before or after passivation of the coating will prevent melanization, (2) PbSO4 micelles adsorbed on the surface of passivated film promote the growth of oxygen-deficient Zn oxide and result in the generation of melanization.
    References | Related Articles | Metrics
    An on-line monitoring system for hydrogen distribution metallic wall caused by hydrogen permeation
    Gang YU, Xueyuan ZHANG, Yuanlong DU
    J. Mater. Sci. Technol., 2001, 17 (03): 346-350. 
    Abstract   HTML   PDF (173KB)
    Based on the electrochemical permeation technique and the patent by Du, an intelligent electrochemical measurement system for determination of the hydrogen distribution in the wall of hydrogenation reactor has been developed and tested. It consists of a PC computer, a single chip unit, an I/V converter and an electrochemical hydrogen probe. The construction of the electrochemical hydrogen probe is described and the features of the measured system are given. The diffusion coefficient of 2.25Cr1Mo steel determined with present system was in good agreement with the value in the literature. Experimental results of hydrogen concentration in a wall of hydrogen charged testing autoclave made of AISI 321 stainless steel are presented. The present system can intelligently display hydrogen amount-of-substance concentration and mass fraction concentration, hydrogen concentration distribution curves in steels, permeation current density curve. An intelligent detection technique can be provided for predicting the susceptibility to hydrogen-induced cracks owing to hydrogen permeation in the wall of hydrogenation reactor in the field.
    References | Related Articles | Metrics
    Preparation and properties of some chemical and electrochemical gamma-MnO2
    H.M.Abbas, Kh. S.Abou-El-Sherbini, M.H.Askar, A. M. Hashim
    J. Mater. Sci. Technol., 2001, 17 (03): 351-354. 
    Abstract   HTML   PDF (124KB)
    Chemically prepared electrolytic gamma -MnO2 and an electrodeposited MnO2 doped with Ce(III) were subjected to physicochemical studies. X-ray diffractometry, density measurements, chemical analysis and thermal analysis were used to determine the structure and chemical disorder present. The samples prepared chemically (CMD) or electrochemically (EMD) showed a variable amount of de Wolff disorder (P-r) and microtwinning (T-w). Manganese dioxide prepared in the presence of Ce(III) showed appreciable decrease in de Wolff defect and a large amount of microtwinning. Thermal analysis showed a loss of weight due to the physically adsorbed and the structural (OH) water, from which the activation energy was calculated. Chemical composition and formulae calculated on the bases of cation vacancy model, cleared that Ce(III)-doped sample has a remarkable increase in the vacancies population associated with higher structural water content. This leads to lower activation energy of water release, and consequently it is supposed to acquire higher electrochemical activity.
    References | Related Articles | Metrics
    Studies on the construction parameter of an artificial occluded cell for in-situ inspection of the propagation rate of localized corrosion
    Liangcai LEI, Fengping WANG, Yanmin GAO, Yuanlong DU
    J. Mater. Sci. Technol., 2001, 17 (03): 355-358. 
    Abstract   HTML   PDF (138KB)
    An artificial localized corrosion system is assembled and some parameters related to the localized corrosion in active dissolution state (i.e., non-passive state) have been studied. The results showed that the developed electrochemical system can satisfactorily imitate a naturally formed localized corrosion and the coupling current can indicate the maximum localized propagating rate. In this artificial system, the anodic dissolution reaction followed the auto-catalytic mechanism. The localized corrosion current density was dependent on the area ratio R of the cathode to the occluded anode. While R was equal to or more than 6, the coupling current reached at a maximum value and did not alter with the increase in R-value. Therefore, R=7 is chosen as one of these optimum parameters used in constructing the system, with which the biggest galvanic current might be obtained. In contrast, the thickness of the polymer filler separating the occluded anode area from the bulk electrolyte solution and the volume of the occluded anode area did not affect the corrosion current obviously. They might affect the response time to approach a steady state.
    References | Related Articles | Metrics
    Martensite aging effect and thermal cyclic characteristics in Ti-Pd and Ti-Pd-Ni high temperature shape memory alloys
    Wei Cai, Kazuhiro Otsuka
    J. Mater. Sci. Technol., 2001, 17 (03): 359-362. 
    Abstract   HTML   PDF (164KB)
    The effect of thermal cycling and aging in martensitic state in Ti-Pd-Ni alloys were investigated by DSC and TEM observations. It is shown that the thermal cycling causes the decreases in M, and Af temperatures in Ti50Pd50-xNix (x=10, 20, 30) alloys, but no obvious thermal cycling effect was observed in Ti50Pd50Pd40Ni10 alloys and the aging effect shows a curious feature, i.e., the Af temperature does not saturate even after relatively long time aging, which is considered to be due to the occurrence of recovery recrystallization during aging.
    References | Related Articles | Metrics
    Dislocation velocity exponent and the strain rate
    Hongyan LIU, Xiaowei WANG
    J. Mater. Sci. Technol., 2001, 17 (03): 363-366. 
    Abstract   HTML   PDF (113KB)
    The process of dislocation multiplication has been described hv chaos theory, trying to reveal the connection between the microstructures on the mesoscopic scale and the mechanical properties of material on the macroscopic scale. The relationship between the dislocation velocity exponent and the maximum of strain rate is given. The results obtained from logistic equation with exponent and the dislocation multiplication dynamic equation are compared. A scale law in one-dimension-map model with exponent is shown when the exponents of equations are changed.
    References | Related Articles | Metrics
    Viscoelastic properties and bioactivity of sol-gel derived gelatin-silicate composites: Effects of the incorporated Ca2+ ions
    L.Ren, K.Tsuru, S.Hayakawa, A.Osaka
    J. Mater. Sci. Technol., 2001, 17 (03): 367-370. 
    Abstract   HTML   PDF (166KB)
    Several gelatin-silicate composites, with or without incorporation of Ca2+ ions, were synthesized through set-gel processing starting from gelatin and 3- (glycidoxypropyl) trimethoxysilane. The structure around the Si atoms was similar for all the samples. The measurement of viscoelastic properties indicated that the glass transition temperature and activation energy decreased with the incorporation of Ca2+ ions. The Ca2+ ion-containing composites were bioactive as they spontaneously deposited apatite when soaked in a simulated body fluid of the Kokubo recipe.
    References | Related Articles | Metrics
    Electrical properties of expanded graphite intercalation compounds
    Xiuyun CHUAN, Daizhang CHEN, Xunruo ZHOU
    J. Mater. Sci. Technol., 2001, 17 (03): 371-374. 
    Abstract   HTML   PDF (139KB)
    The intercalation compounds of CuCl2 were synthesized with expanded graphite, whose magnitude of the electrical conductivity is about 10(3)S(.)cm(-1). Their electrical conductivity is 3 similar to6 times as high as that of the expanded graphite, and about 10 times as high as that of GIC made of the non-expanded graphite. The microanalysis results of chemical compounds by X-ray energy spectrum scanning of TEM testified that the atomic ratio of chloride and cupric is nonstoichoimetric. The multivalence and exchange of electrovalence of the cupric ion was confirmed by the XPS-ESCA. Vacancy of chlorine anion increases the concentration of charge carrier. The special stage structure, made of graphite and chloride, produces a weak chemical bond belt and provides a carrier space in the direction of GIC layer. These factors develop the electrical properties.
    References | Related Articles | Metrics
    Rheological behavior for polymer melts and concentrated solutions Part VII: A quantitative verification for the molecular theory of non-linear viscoelasticity with entanglement constraints in polymer melts
    Mingshi SONG, Chen ZHANG, Guixian HU
    J. Mater. Sci. Technol., 2001, 17 (03): 375-382. 
    Abstract   HTML   PDF (257KB)
    Based on the molecular theory of non-linear viscoelasticity with constrained entanglements in polymer melts, the material functions in simple shear flow were formulated, the theoretical relations between. eta((gamma) over dot), psi (10)((gamma) over dot) and shear rate ((gamma) over dot), and topologically constrained dimension number n ' and a were derived. Linear viscoelastic parameters (eta (0) and G(N)(0)) and topologically constrained dimension number (n ' a and <()over bar>) as a function of the primary molecular weight (M-n), molecular weight between entanglements (M-C) and the entanglement sites sequence distribution in polymer chain were determined. A new method for determination of viscoelastic parameters (eta (0), psi (10), G(N)(0) and J(e)(0)), topologically constrained dimension number (n ', a and v) and molecular weight (M-n, M-c and M-e) from the shear flow measurements was proposed. It was used to determine those parameters and structures of HDPE, making a good agreement between these values and those obtained by other methods. The agreement affords a quantitative verification for the molecular theory of nonlinear viscoelasticity with constrained entanglement in polymer melts.
    References | Related Articles | Metrics
    Local nanocrystallization in a Cr-Mn-N austenitic stainless steel caused by cavitation
    Zhechang WANG, Xiaoqiang ZHANG, Huaining CHEN
    J. Mater. Sci. Technol., 2001, 17 (03): 383-384. 
    Abstract   HTML   PDF (409KB)
    Many nanocrystallized areas have been found with transmission electron microscope (TEM) in a Cr-Mn-N austenitic stainless steel after cavitation erosion. It has been found that the nanocrystallized areas were formed in the severe cavitation zone and the grain size was about 25 nm. A possible nanocrystallization mechanism is given.
    References | Related Articles | Metrics
    Study on an explosion treated steel weld metal with prepared crack
    Xiaonan GUO, Xin LONG, Huaining CHEN, Liangshan CHEN, Guangjun GAI
    J. Mater. Sci. Technol., 2001, 17 (03): 385-387. 
    Abstract   HTML   PDF (804KB)
    A softening zone with recrystallized grain around the prepared crack tip in the shock waves treated C-Mn steel weld metal was observed. It is suggested that a dynamic recovery occurred around the prepared crack tip even at a low explosion pressure (5 GPa) because of the stress and strain concentration at the crack tip when shock waves pass through. This result supports the previous work on the improved mechanical properties of a shock treated welded joint with residual crack from the viewpoint of microstructure.
    References | Related Articles | Metrics
    Stress field of non-equilibrium grain boundaries in nano-crystalline metals
    Chiwei LUNG, Enke TIAN, Hengqiang YE
    J. Mater. Sci. Technol., 2001, 17 (03): 388-388. 
    Abstract   HTML   PDF (246KB)
    Introducing the stress distribution near grain boundaries to improve the dislocation pileup model for the Halt-Petch (H-P) relation, the continuous distribution of dislocations in the pileup could be solved by means of Tschebysheff polynomials for the Hilbert transformation. An analytical formula of the stress intensity factor for the dislocation pileup is obtained. The reverse H-P relation may be explained by the modified dislocation-pileup-model.
    References | Related Articles | Metrics
ISSN: 1005-0302
CN: 21-1315/TG
Home
About JMST
Privacy Statement
Terms & Conditions
Editorial Office: Journal of Materials Science & Technology , 72 Wenhua Rd.,
Shenyang 110016, China
Tel: +86-24-83978208
E-mail:JMST@imr.ac.cn

Copyright © 2016 JMST, All Rights Reserved.