Q.R. Zhang
,
Y.G. Li and Z. Fang (Department of Chemistry
,
Central South University of Technology
,
Changsha 410083
,
China)(Department of Chemistry
,
Central South University of Technology
,
Changsha 410083
,
China)(Department of Chemistry
,
Central South University of Technology
,
Changsha 410083
,
China)
金属学报(英文版)
In orber to calculate the activity coefficients of water in the aqueous solution systems of double electrolytes, HCl and MCln (M=Ni, Cu,Na and Fe), a simplified regular solution model has been derived based on the assumption that the electrolytes in the aqueous solution are treated as independent particles instead of their ion forms, and that the interaction of the component pair HCl-MCln in the aqueous solution is very weak as compared with the component pairs HCl-H2O and H2 O-MCln. The interchange energies of the component pairs in the discussed systems, ωWCl-H2o, ωH2o-NiCl2,ωH2o-CuCl2, ωH2o-NaCl and ωH2O-FeCl3, have been evaluated from the experimental data to be-69800, -212600, -90550, -42450 and -198310J·mol-1.
关键词:
solution model; interchange energy; electrolyte solution
QIAO Lijie LIU Rui XIAO Jimei University of Science and Technology Beijing
,
Beijing
,
China
金属学报(英文版)
The effects of stress components on nucleation sites and propagation directions of stress cor- rosion cracks in brass were investigated with specimens under mode Ⅱ and mode Ⅲ loadings. The results indicated that under mode Ⅱ loading,stress corrosion cracks nucleated on the site with maximum normal stress component and propagated along the plane perpendieular to the maximum normal stress,under mode Ⅲ loading,the stress corrosion crack was not evident on the 45°plane due to the general corrosion in aqueous solution with high NH_4OH concentra- tion,while stress corroded in aqueous solution with low NH_4OH concentration, numerous cracks with spacings of 10—150μm were found on the 45°plane with maximum normal stress and no stress corrosion cracks was observed on the plane with maximum shear stress.
关键词:
stress corrosion cracking
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null
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null
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LIANG Yong LI Ruiguo Institute of Metal Research
,
Academia Sinica
,
Shenyang 110015
,
ChinaInstitute of Corrosion and Protection of Metals
,
Aademia Sinica
,
Shenyang
,
110015
,
China
材料科学技术(英文)
Recent advances in laser coating technology including laser cladding,laser surface alloying and laser vapour deposition in China are reviewed in this paper.
关键词:
laser
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null
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null
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null
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Acta Physico-Chimica Sinica
Adsorption of thiourea (TU) and ethylthiourea( ETU) on roughened silver electrode was investigated using in situ surf. enhanced Raman spectroscopy(SERS) Using quantum chemistry and HSAB theories, the influences of electrode potential and the different substituent groups on SERS were disc i. TU is chemisorbed perpendicularly by Ag-S bond on silver at E = -0.3 V and adsorption of TU turns into a parallel orientation at E = -0.9 V. ETU is always chemisorbed at an angle from Ag. The adsorption of ETU is through and C=C and C=O groups at E = -0.3 V, and mainly through C=C at E = -0.9V.
关键词:
Surface enhanced Raman spectroscopy;Adsorption;Quantum chemistry;Thiourea;Inhibitor
Shanthi Subramanian
,
David Muller
,
John Silcox and Stephen L.Sass (Department of Materials Science and Engineering and Department of Applied and Engineering Physics
,
Cornell University
,
Ithaca. NY 14853)
金属学报(英文版)
Local chemistry plays an important role in determining the cohesive strength of grain boundaries in Ni3Al. Doping with B increases the room temperature ductility and changes the fracture mode from intergranular to transgranular, while doping with Zr increases the ductility but leaves the fracture mode predominantly intergranular.Electron Energy Loss Spectroscopy (EELS) and Energy Dispersive X-ray Spectroscopy (EDS) were used to probe the changes in local bonding (and hence the cohesive strength) produced by changes in local chemistry at large angle boundaries in Ni3Al.In addition , small angle tilt boundaries were studied to correlate structure with Nienrichment at the interface. B segregation to Ni-rich grain boundaries was shown to make the bonding similar to that of the bulk, thereby increasing their fracture resistance. Ni-enrichment does not occur in the presence of Zr segregation to grain boundaries. Ni-enrichment to antiphase boundaries (APB) in small angle tilt boundaries lowers the APB energy by reducing the number of high energy Al-Al interactions across the interface. Ni-enrichment to large angle boundaries is expected to produce a similar effect on energy.
关键词:
: grain boundary chemistry
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null
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null
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