Electrochimica Acta
The inhibition by 2-mercaptobenzoxazole (MBO) of copper corrosion in NaCl solution was investigated by means of potentiodynamic polarization, STM: QCM, XPS, FTIR and AES. The inhibition efficiency depended on MBO concentration, existence of NaCl and the immersion period of the copper sample. The inhibition efficiency of about 99% could be obtained by immersing for above 20 h in 3% NaCl + 1 mM MBO solution. The surface of the copper sample immersed in NaCl + MBO solution possessed FTIR characteristics different from those of MBO solution, irrespective of immersion time. The in-situ STM morphologies showed the rapid formation of a three-dimensional compact inhibition film on the surface of copper in MBO solution containing NaCl. XPS indicated that the inhibition film was cuprous and the chemical environments of S and N atoms were evidently changed. It is concluded that MBO reacted with the cuprous species from the corrosion process, and produced a water-insoluble cuprous complex to form the inhibition film and to retard the corrosion of copper. (C) 2000 Elsevier Science Ltd. All rights reserved.
关键词:
corrosion inhibition;copper;2-mercaptobenzoxazole;STM;QCM;heterocyclic-compounds;chloride media;benzotriazole;efficiency;electrode;behavior;films;sers;xps;cu
Materials Science and Technology
kThe compound Ti3SiC2 is a promising reinforcement for copper, but at a high volume content of Ti3SiC2, densification of Cu/Ti3SiC2 composites becomes difficult. To improve the densification behaviour and microstructure of Cu/Ti3SiC2 composites, Ti3SiC2 particulates were coated with a layer of copper by an electroless plating method before being incorporated into the copper matrix. Results demonstrated that, compared with uncoated Ti3SiC2 reinforced copper, copper coated Ti3SiC2 reinforced composites exhibit both high density and a homogeneous distribution of Ti3SiC2 within the copper matrix. The precoated layer of copper prevents direct contact and agglomeration of Ti3SiC2 particulates. Owing to the improved density and microstructure, the mechanical properties of Cu/Ti3SiC2 composites are also enhanced. Mechanical property investigation revealed that a significant strengthening effect is observed for Cu/Ti3SiC2 composites at both room and high temperatures.
关键词:
metal matrix composites;particulate composites;copper alloys;titanium;compounds;mechanical properties;titanium-silicon carbide
Dongming GUO
材料科学技术（英文）
For the first time, the texture of copper and Cu-ZrB2 coatings produced from copper nitrate solution was studied. Chloride ion shows different effects on the deposit texture under direct current (DC) and pulse current (PC) conditions. Copper deposits are strongly <220> textured in DC plating with and without chloride ion. While in PC condition, the predominant texture shifts from <220> to <200> as the chloride ion concentration exceeds 20 mg/l. The addition of ZrB2 particles enhances the cathodic polarization of copper deposition, which improves the growth of (111) plane. However, this improvement can be eliminated by further addition of chloride ion.
关键词:
Texture
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null
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null
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null
WU Tong
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CHENG Su-sen
钢铁研究学报(英文版)
Copper staves have been equipped on nearly all of BF (blast furnaces) with volume over than 1000 m3 in China since their introduction from abroad about more than 10 years ago. Because of short application and lack of experience, phenomena of thickened or naked of copper stave happen occasionally which influence production severely. So it is important to study the model of forming-accretion on BF copper stave and realize real-time monitoring of forming-accretion on different copper staves. Therefore, mathematic model of calculating accretion thickness by heat flow of BF is proposed, and the calculated results indicate that accretion thickness could be kept at a reasonable range of around 50 mm by controlling heat flux around 22.0 kW/m2. The monitoring program based on the model was applied to a certain BF in China successfully, and it is found that slip of BF near the inner wall is one of most important reasons that cause fluctuation of accretion thickness. During the period of scheduled maintenance of the certain BF, the thickness of accretion measured through the static pressure holes is in good accordance with the value calculated by the monitoring program, so the results calculated by the monitoring program can be used to guide industrial production.
关键词:
blast furnace
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copper stave
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forming-accretion
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monitor
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industrial application
H.Z. Yang
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X.G. Sun
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W.Q.Huang
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M.L. Li
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X.M. Yu
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B.S.Zhang
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Y.Qi
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Q. Zhao
金属学报(英文版)
An electrochemical technique has been introduced and applied to fabricate superconducting MgB2 films in molten salts. MgCl2, Mg(BO2)2, NaCl, and KCl were used as electrolyte, graphite was used as the anode, and copper was used as the cathode, respectively. X-ray diffraction (XRD) analysis was chosen to investigate the phase composition and crystallinity of the films at different electrolysis temperatures. Standard four-probe technique and SQUID were applied to investigate the temperature dependence of resistance (R-T) properties and magnetic properties of the films, respectively. The results indicate that MgB2 films have been fabricated on the copper cathodes, and superconducting transition takes place close to 50 K.
关键词:
MgB2 film
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null
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null
Zeitschrift Fur Metallkunde
Ti2SnC dispersion-strengthened (DS) copper matrix composites were prepared by the hot-pressing method. The change of microstructure, mechanical properties, and electrical resistivity of the composites as a function of Ti2SnC volume fraction were studied. The results demonstrated that the grain size of Cu decreased pronouncedly by incorporating Ti2SnC, and the strengthening effect was significant. Improvements in yield strength of up to four times that of pure copper were found in Cu-1 vol.% Ti2SnC, however, the conductivity of the composite was still 85.6 % of pure copper. The high strength and low electrical resistivity indicated that Ti2SnC is a promising reinforcement for copper.
关键词:
Cu;Ti2SnC;mechanical properties;electrical resistivity;composites;particles;stability;behavior
SUN Wenqiang
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CAI Jiuju
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MAO Hujun
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GUAN Duojiao
钢铁研究学报(英文版)
As the largest energy consuming manufacturing sector and one of the most important sources of carbon dioxide (CO2) emissions, the China′s iron and steel industry has paid attention to the study of changing trend and influencing factors of CO2 emissions from energy use. The logarithmic mean Divisia index (LMDI) technique is used to decompose total change in CO2 emissions into four factors: emission factor effect, energy structure effect, energy consumption effect, and steel production effect. The results show that the steel production effect is the major factor which is responsible for the rise in CO2 emissions; whereas the energy consumption effect contributes most to the reduction in CO2 emissions. And the emission factor effect makes a weak negative contribution to the increase of CO2 emissions. To find out the detailed relationship between change in energy consumption or steel production and change in CO2 emissions, the correlation equations are also proposed.
关键词:
CO2 emissions
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energy use
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LMDI technique
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steel production
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energy consumption
American Mineralogist
A natural high-pressure phase of titanium oxide with alpha-PbO2-structure has been found in omphacite from coesite-bearing eclogite at Shima in the Dabie Mountains, China. High-resolution transmission electron microscope observations have revealed an orthorhombic lattice, corresponding to alpha-PbO2-type TiO2, with cell parameters a = 0.461 nm, b = 0.540 nm, c = 0.497 nm and space group Pbcn. It occurs as nanometer-thick (< 2 nm) lamellae between multiple twinned rutile crystals, providing additional evidence of very high-pressure, metamorphism at 7 GPa, 900 degrees C. This implies subduction of continental material to a depth of more than 200 kilometers. alpha-PbO-type TiO2 could be an extremely useful index mineral for ultrahigh-pressure.
关键词:
high-pressure phase;ries crater;rutile;polymorph;titanium
