ZHOU Jiyang Dalian University of Technology
,
Liaoning
,
ChinaW.SCHMITZ S.ENGLER Aachen Institute of Technology
,
FRG Associate Professor
,
Divisionof Foundry
,
Dalian Institute of Technology
,
Liaoning
,
China
金属学报(英文版)
To study the growth of austenitic shells around the spheroidal graphite,color metallography has been employed.It is found that the shell is not a continuous layer of austenite,but a clus- ter of wedge-shaped crystals.Three types of shells have been observed.That may strongly af- fect the deterioration of the spheroidal graphite.The mechanism of the formation of the austenitic shells has also been discussed.
关键词:
Spheroidal graphite
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null
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null
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Fresenius Journal of Analytical Chemistry
A sensitive method for the determination of traces of P in Fe, Ni, Co, Cu and Zn is based on the formation of an ion-associate with molybdate and malachite green, whose absorbance is measured at 620 nm. The calibration curve is linear up to 0. 1 0-mu-g/ml; molar absorptivity is 2.7 x 10(5) l mol-1 cm-1. It was found that commonly coexisting elements did not interfere.
关键词:
Campbell Laird(Dept. of Materials Science & Engineering
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University of Pennsylvania
,
Philadelphia
,
PA 19104-6272
,
USA)Pedro Peralta(Center for Materials Science
,
Los Alamos National Laboratory
,
MaU Stop K765
,
Los Alamos
,
NM 87545-0001
,
USA)
材料科学技术（英文）
The mechanisms of fatigue crack propagation are breifly reviewed in relation to Professor McClintock's contributions to the early development of the field. The most securely established understanding has been obtained for those mechanisms of propagation involving plasticity-inducedgeometrical changes to the crack tip during tensile and compressive straining (the plastic blunting process). The roles of more complex factors in controlling the kinetics of crack propagation,which cause the magnitude of the Paris exponent to exceed 2, remain to be elucidated. Recentlyobtained results revealing the interconnection between the slip behaviour at the crack tip, theplastic blunting process and the dislocation structures present in the material before the crackencounters them are reported.
关键词:
WU Chuansong
,
CAO Zhenning
,
WU Lin Harbin Institute of Technology
,
Harbin
,
China
金属学报(英文版)
A model is established to analyze three-dimensional fluid flow and heat transfer in TICweld pools with full penetration.It considers the deformation of the molten pool surfaceat the condition of full penetrated workpieees,takes the are pressure as the drivingforce of the pool surface deformation,and determines the surface configuration of weldpool based on the dynamic balance of arc pressure,pool gravity and surface tension atdeformed weld pool surface. The SIMPLER algorithm is used to calculate the fluid flowfield and temperature distribution in TIG weld pools of stainless steel workpieces.TIGwelding experiments are made to verify the validity of the model.It shows the calculatedresults by the model are in good agreement with experimental measurements. professor,Dept of Welding Engineering,Harbin Institute of Technology,Harbin 150006,China
关键词:
KEY WORDS TIG weld pool
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null
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Journal of the Electrochemical Society
A new method for preparing effective inhibition film on copper has been developed. Phenylthiourea was first adsorbed to a copper surface to form a self-assembled film. 1-Dodecanethiol was then self-assembled on the surface for subsequent modification. Finally, ac voltage was loaded on copper covered with the mixed film to further modify the film. After these procedures, an effective inhibition film was obtained as indicated by the low corrosion current density in polarization curves. High charge-transfer resistance in electrochemical impedance spectra reveals that the film hinders corrosion electrochemical reaction between the copper surface and NaCl solution. Film coverage on the copper surface is more than 99.0%, and inhibition efficiency is more than 97.2% in 0.5 mol dm(-3) NaCl solutions. The mixed films before and after ac treatment are stable in a wide region of potentials. X-ray photoelectron spectroscopy analysis reveals that the effect of ac treatment may associate with the formation of a new complex compound. (C) 2003 The Electrochemical Society.
关键词:
impedance spectroscopy;gold;monolayers;protection;electrode;alkanethiols;behavior;thiourea;electrodissolution;mechanisms
International Journal of Hydrogen Energy
Various carbon additives were mechanically milled with LiBH(4)/MgH(2) composite and their hydrogen storage behaviors were investigated. It was found that most of the carbon additives exhibited prominent effect on the host material. Among the various carbon additives, purified single-walled carbon nanotubes (SWNTs) exhibited the most prominent effect on the kinetic improvement and cyclic stability of Li-Mg-B-H system. Results show that LiBH(4)/MgH(2) composite milled with 10 wt.% purified SWNTs additive can release nearly 10 wt.% hydrogen within 20 mm at 450 degrees C, which is about two times faster than that of the neat LiBH(4)/MgH(2) sample. On the basis of hydrogen storage behavior and structure/phase investigations, the possible mechanism involved in the property improvement upon carbon additives was discussed. (C) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.
关键词:
Hydrogen storage;Lithium borohydride;MgH(2);Carbon;Mechanical;milling;arc-discharge method;libh4;nanotubes;composites;hydride
