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Preparation and corrosion Resistance of Magnesium Coatings by Magnetron Sputtering Deposition

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Journal of Materials Science & Technology 2003年第5期19卷 459-462页

作者： Hongwei HUO, Ying LI and Fuhui WANGState Key laboratory for corrosion and protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China State Key laboratory for corrosion and protection Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

Magnesium coatings were fabricated on stainless steel substrates (1Cr11Ni2W2MoV) by a plane magnetron sputtering technique. The argon pressure and the substrate condition (including temperature and the substrate was rotated or fixed) were varied in order to evaluate the influence of the parameters on the crystal orientation and morphology of the coating. The corrosion behavior of the coatings in 1 wt pct NaCI solution was studied by electrochemical methods. The results showed that all coatings exhibited preferred orientation (002) as the argon pressure increased from 0.2 to 0.4 Pa. The morphologies of the coatings varied with the argon pressure and with whether the substrate was rotated or fixed. The open circuit potential of the coatings was more positive than that of cast AZ91D magnesium alloy. However, the immersion test in 1 wt pct NaCI solution showed that the corrosion rates of the coatings were higher than that of cast AZ91D magnesium alloy.

关键词： Magnesium coating corrosion Magnetron sputtering deposition

Microstructural characterization of internal oxidation of AgCu alloy

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Science China(Technological Sciences) 1997年第2期40卷 156-163页

作者：彭晓李铁藩吴维 平德海 State Key laboratory for corrosion and protection of Metals Institute of Corrosion and Protection of Metals Chinese Academy of Sciences Shenyang 110015 China laboratory of Atomic Imaging of Solids Institute of Metal Research Chinese Academy of Sciences Shenyang 110015 China

The internal oxidation of AgCu alloys with atomic percentage 0.8,3 3, 6 3 and 9 5 of Cu in air at 750℃ and 850℃ has been studied. It was found that CuO particles precipitated homogeneously on the surface of AgCu alloys except for Ag-9.5% (atomic percentage) Cu. The latter exhibited the agglomerated precipitation of CuO particle cluster on the surface. The experimental results also revealed that the nucleation and growth of CuO oxide evidently varied with the change of Cu contents or oxidation temperature. When both Cu content and exposure temperature were low, the precipitation and the growth of internal CuO oxide were consistent with the prediction by the classical Bohm-Kahlweit mode, but the abnormal phenomenon of nucleation and growth of the CuO oxide was observed when the Cu content or the exposure temperature was increased. As a result of investigation of the atomic structure of different internally oxidized AgCu alloys, it is proposed that the stacking fault tetrahedra(SFT), which were found in the oxidized alloys, promoted the nucleation of CuO internal oxide.

关键词： AgCu alloy internal oxidation microstructure stacking fault tetrahedron.

Fire and corrosion Resistances of Intumescent Nano-coating Containing Nano-SiO_2 in Salt Spray Condition

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Journal of Materials Science & Technology 2010年第1期26卷 75-81页

作者： Zhenyu Wang Enhou Han Fuchun Liu Wei Ke State Key laboratory for corrosion and protection Institute of Metal Research Chinese Academy of Sciences Shenyang110016 China

The nano-concentrates and flame retardant nano-coating were prepared in thhis study. The effect of nano-SiO2 on the corrosion resistance and fire resistance of ammonium polyphosphate-pentaerythritol-melamine （APP- PER-MEL） coating was investigated by differential thermal analysis （DTA）, scanning electron microscopy （SEM）, effective thermal conductivity （λ/d）, X-ray photoelectron spectroscopy （XPS） and fire protection test. The chemical action and endothermic effect of ammonium polyphosphate, pentaerythritol and melamine in traditional flame retardant coating were damaged by salt spray condition, whereas the flame-retardant additives in the nano-coating demonstrated the good chemical interaction in salt spray condition. The uniformly dispersed nano-SiO2 particles could improve corrosion resistance of the coating, and hence nano-coating could remain the good fire-resistant properties even after 500 h salt spray test.

关键词： Nano-SiO2 APP-PER-MEL coating Nano-coating Salt spray test Fire-resistant property

Electro-spark epitaxial deposition of NiCoCrAlYTa alloy on directionally solidified nickel-based superalloy

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Transactions of Nonferrous Metals Society of China 2010年第5期20卷 795-802页

作者：王茂才王维夫谢玉江张杰 State Key laboratory for corrosion and protection Institute of Metal ResearchChinese Academy of Sciences School of Science Northeastern University

An 8 mm-high NiCoCrAlYTa coating was epitaxially built-up on a directionally solidified (DS) Ni-based superalloy blade tip by electro-spark *** morphologies of the coating and its microstructural characteristics were investigated by means of SEM,XRD and TEM *** is observed that the fine column-like dendrites originated from the γ'-particles or γ'-clusters of the DS substrate and are un-continuously *** β-phase particles precipitate and grow eutectically with the γ-*** orientation of fine column dendrites depends on electro-spark deposition processing parameters and the microstructure can be characterized with superfine γ and β phases.

关键词： electro-spark deposition epitaxial growth MCrAlY alloy Ni-base superalloy

Influence of an External Magnetic Field on the Growth of Nanocrystalline Silicon Films Grown by MF Magnetron Sputtering

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Journal of Materials Science & Technology 2012年第11期28卷 992-998页

作者： Junhua Gao Lin Zhang Jinquan Xiao Jun Gong Chao Sun Lishi Wen State Key laboratory for corrosion and protection Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

The effects of an external magnetic field originating from two solenoid coils on the magnetic field configuration, plasma state of a dual unbalanced magnetron sputter system and the structure of nanocrystalline Si films were examined. Numerical simulations of the magnetic field configuration showed that increasing the coil current significantly changed the magnetic field distribution between the substrate and targets. The saturated ion current density Ji in the substrate position measured by using a circular flat probe increased from 0.18 to 0.55 mA/cm2 with the coil current ranging from 0 to 6 A. X-ray diffraction and Raman results revealed that increasing the ion density near the substrate would benefit crystallization of films and the preferential growth along [lI1] orientation. From analysis of the surface morphology and the microstructure of Si films grown under different plasma conditions, it is found that with increasing the Ji, the surface of the film was smoothed and the alteration in the surface roughness was mainly correlated to the localized surface diffusion of the deposited species and the crystallization behavior of the films.

关键词： Nanocrystalline silicon Thin film Solenoid coil MF magnetron sputtering

Effect of element Gd on phase constituent and mechanical property of Mg-5Sn-1Ca alloy

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Transactions of Nonferrous Metals Society of China 2010年第B07期20卷 341-345页

作者：施斌卿陈荣石柯伟 State Key laboratory for corrosion and protection Institute of Metal Research Graduate School of the Chinese Acade my of Sciences

The Mg-5Sn-1Ca-xGd (x=0, 1) alloys were chosen to investigate the change in solidification paths, phase formation and mechanical properties. The microstructure of as-cast Mg-5Sn-1Ca alloy is composed of α-Mg, Mg2Sn and CaMgSn phases. With the addition of Gd, the formation of the Mg2Sn phase is impeded and the CaMgSn phase is refined, whereas the ultimate tensile strength and elongation decrease. The possible reasons for the variation in microstructure and mechanical properties were discussed.

关键词： magnesium alloy Mg-Sn-Ca alloy thermal analysis mechanical property

Determination of Water Sorption in Freestanding Epoxy Film by Capacitance Method Using EIS

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Journal of Materials Science & Technology 2006年第1期22卷 108-112页

作者： Yinghua WEI Lixin ZHANG Wei KE State Key laboratory for corrosion and protection Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

Electrochemical impedance spectra （EIS） technique was adopted to evaluate the water sorption behaviour of an epoxy freestanding film in a 0.5 mol/L sodium chloride solution at 20℃. The methods for obtaining the capacitance data from EIS data were compared. The Brasher-Kingsbury （BK） and corresponding modified version （Modi-BK） models were used to calculate the water uptake in film and the gravimetric results were presented for comparisons. According to the discussion of the discrepancy of water content in film obtained from two models, a new method was proposed to indicate the organic film structure.

关键词： Epoxy Capacitance Water sorption EIS

Laser surface cladding of ZM5 Mg-base alloy with Al+Y powder

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中国有色金属学会会刊：英文版 2004年第6期14卷 1091-1094页

作者：陈长军王东生王茂才 State Key laboratory for corrosion and protection Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

The surface properties of ZM5 Mg-base alloy were modified by laser cladding with Al+Y powder. Laser cladding was carried out with a 5 kW continuous wave CO2 laser by melting the preplaced powder mixture of Al and Y. Following laser cladding, the cladding zone was characterized by a detailed microstructural observation and phase analysis. Moreover, the microhardness and element distribution were evaluated in detail. The surface modified layer consists of Mg17Al12 and Al4MgY phases, while α-Mg and Mg17Al12 in the substrate. The microhardness of the cladding zone was significantly enhanced as high as HV122180 as compared to HV6080 of the substrate region. The maximal hardness about HV224 is in the interface due to the formation of intermetallic Mg17Al12 phase. The microstructure is refined and Mg diffuses into the cladding material which leads to the formation of Mg17Al12.

关键词：激光金属包覆 ZM5镁基合金稀土元素铝粉微观结构

corrosion Evolution of Reinforcing Steel in Concrete under Dry/Wet Cyclic Conditions Contaminated with Chloride

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Journal of Materials Science & Technology 2012年第10期28卷 905-912页

作者： J.Wei X.X.Fu J.H.Dong W.Ke State Key laboratory of corrosion and protection Institute of Metal ResearchChinese Academy of SciencesShenyang110016~China

The corrosion evolution of rebar in concrete was monitored by electrochemical impedance spectroscopy （EIS） under dry/wet alternated accelerated corrosion test. Four stages with different dynamic characteristics were observed during the corrosion evolution. They were passive stage, local corrosion controlled by the charge transfer step, accelerated corrosion controlled by the mass transfer step, and constant rate corrosion controlled by the mass transfer step through a barrier layer. X-ray diffraction （XRD） analysis showed that the corrosion product of rebar in mortar was composed of α-FeOOH, γ-FeOOH and Fe304. The corrosion mechanisms of all four stages were discussed and the corrosion reactions were proposed according to the corrosion product and corrosion evolution characteristics.

关键词： Rebar Concrete Electrochemical impedance spectroscopy (EIS) corrosionevolution