18／8型不锈钢在受力形变条件下腐蚀电化学行为的研究

应用电化学稳态技术、电化交流阻、抗微区电化学技术及扫描电等方法，研究１８／８型不锈钢在Ｎａ２Ｓ２Ｏ３稀溶液中，受外力形变条件下，的腐蚀电化学行为，结果表明，力学因素可使表面腐蚀电化学活性增加，表面微裂纹的发生、消失和再钝化的动态过程，同时受电位和拉应力的影响；点腐蚀可优先发生在应力集中位置，点蚀的发展可能诱导不锈钢的应力腐蚀开裂。     

甲苯胺兰的电化学行为

应用电化学和薄层光谱电化学方法研究甲苯胺兰的还原过程。证明了产物的吸附行为，给出该反应的标准式溻位和电子转移数分别为０．０３８ＶｖｓＮＨＥ和１．９８。提出电还原反应机理，并计算出其还原态的表观酸离解常数分别为ＰＫ１＝４．２和ｐＫ２＝６．５。     

Pt／YSZ固体电解质界面氧的电荷传递过程研究

用极化法研究了不同温度和氧分压下Ｐｔ／ＹＳＺ界面氧的电荷传递过程．研究发现氧电荷传递过程的阴、阳极电荷传递系数为１，不随温度和氧分压而变．从实验和反应机理推导得到，Ｐｔ／ＹＳＺ界面的交换电流密度和氧分压之间存在，ｉ０＝２ＦＫｒ（ＫＯ２ＰＯ２）１／４（１＋ＫＯ２ＰＯ２）１／２的关系．通过数学分析还获电化学反应速度常数，氧在Ｐｔ表面上吸附平衡常数等重要参数     

银电极在Na2SO4溶液中氧化还原过程的原位拉曼光谱研究

采用原位拉曼光谱结合循环伏安法研究银电极在０．１ｍｏｌ／Ｌ的Ｎａ２ＳＯ４溶液中不同电位下的氧化还原过程，在电位扫描过程中，实时记录的拉曼光谱表明，电极表面在０．２Ｖ开始生成吸附原子氧物种，当电位正于０．４Ｖ，部分吸附的原子氧扩散进入电极的亚表面区，而另一些则通过强的化学吸附与银表面成键；同时部分银氧化为＋１价，各谱带的产生和消失与氧化还原电流峰有很好的对应关系，表明电化学原位拉曼光谱能在分子水平上     

电极表面结构及有机添加物对C60电还原过程的影响

研究了不同电极表面结构及有机添加剂对Ｃ６０电化学还原过程的影响。实验结果表明，富勒烯及其阴离子的电还原活性取决于电极表面结构的影响，即：ｉｐｃ（多晶）〉ｉｐｃ［Ｐｔ（１１１）］〉ｉｐｃ［Ｐｔ（１１０）］，且在Ｐｔ（１１１）及Ｐｔ（１１０）晶面上Ｃ６０＾１－及Ｃ６０＾２－的还原电位均有一定的位移。另外，实验结果还表明当溶液中分别添加苯胺及邻氨基酚时，其对Ｃ６０电还原过程的影响机理将有所不同。     

锂离子电池阴极材料尖晶石结构Li1＋xMn2—xO4的研究

本文报导尖晶石结构阴极材料Ｌｉ１＋ｘＭｎ２－ｘＯ４（Ｏ＜ｘ＜１）的制备方法，讨论温度及原料对合成材料的电化学特性的影响，用电化学及结构化学理论研究了化学计量尖晶石结构ＬｉＭｎ２Ｏ４中，过量锂占据晶格中锰的位置，对电池初始容量及循环寿命产生的影响．     

La0.8Sr0.2MnO3／YSZ高温电极交流阻抗研究

用交流阻抗方法研究了Ｌａ０．８Ｓｒ０．２ＭｎＯ３电极上进行的氧化电化学还原反应。实验表明反应速度控制步骤随反应温度，氧分压及过电位发生显著变化，近平衡下反应的ｒｄｓ为氧的解离吸附过程。强阳极极化下，电解质表面产生大量电子空穴；强阴极极化下，ＬＳＭ电极表面形成大量氧空位，二者的结果均使界面电导增加，电化学反应区扩展。     

酸性溶液中离子注入钯的玻璃碳电极上硝基苯的电化学还原

用循环伏安法在离子注入钯的玻璃碳电极上，研究了硝基苯在０．５ｍｏｌ／Ｌ硫酸溶液中的电还原过程，通过ＡＥＳ测量了离子注入电极的表面组成和各元素的浓度－深度分布，在４０ｋｅＶ下，注入剂量为１×ｌ０￣（１７）离子／ｃｍ＿２的钯注入到玻璃碳（ＧＣ）中可产生钯原子最大百分含量为２０％的近表面区。原基体注入钯后比未注入的ＧＣ对硝基苯（ＮＢ）的电还原有更高的活性，用气相色谱法检测到ＮＢ的还原产物苯胺，讨论了硝基苯在酸性溶液中电化学还原机理。     

酸性溶液中Rh电极上CO孪生吸附态的FTIRS研究

采用现场多步ＦＴＩＲ光谱技术结合ＣＯ吸附分子探针方法，研究了Ｒｈ电极表面分子过程，在电化学处理后的光滑Ｒｈ电极表面上首次检测到两种ＣＯ孪生吸附态及其随电位变化过程，使用电位循环扫描方法改变Ｒｈ电极表面状态，在０．０５ｍｏｌ／Ｌ，Ｈ２ＳＯ４酸性溶液中，取取－０．２７５至２．４Ｖ电位区间和１．５Ｖ／ｓ扫描速率对Ｒｈ电极进行循环扫描处理２ｍｉｎ处理后的Ｒｈ电极表面积累一层氧化物，ＣＯ以孪生态吸附于表面Ｒ     

头孢噻甲羧肟的伏安行为及其单扫描极谱法测定

以多种电化学手段研究了头孢噻甲羧肟的伏安行为。在磷酸盐缓冲溶液中，ＣＴＤ产生２个不可逆吸附还原波，峰电位分别为－０．６５Ｖ和－１．２０Ｖ。分别有１个电子与２个电子和１个质子参与了峰１与峰２的电极过程。探讨了电极反应机理。     

Heterogeneous surface properties on wallstents

Wallstent has been successfully used to open up clogged peripheral arteries. Co? Cr alloy is the preferred metal for the construction of wallstent. Unfortunately, major complications such as in‐stent intimal hyperplasia,stent obstruction, and stent stricture are often reported, and these complications could be related to the metallic properties of the wallstent. In this study, the electrochemical properties of Co? Cr wires from wallstent were investigated using cyclic polarization, open‐circuit potential, potentiostatic condition, and electrochemical impedance spectroscopy. Scanning electron microscopy and X‐ray mapping were also employed to investigate the surface morphology and elemental distribution after electrochemical measurement. Results of this study showed the heterogeneous electrochemical properties of Co? Cr alloy wires that could result in severe galvanic corrosion of wallstent after implantation. Severe corrosion process could cause fracture of wallstent, resulting in localized inflammation, allergy, and thicker neointima. Copyright © 2009 John Wiley & Sons, Ltd.     

Active protective Al–Ce alloy coating electrodeposited from ionic liquid

The electrochemical co-deposition of Al–Ce metallic protective coating with active inhibiting effect was performed for the first time using an ionic liquid as an electrolyte. Cerium was successfully co-deposited with aluminium on surface of Pt and AA2024 aluminium alloy forming uniform films with globular micro-structure and thickness up to 75 μm.Cerium was introduced into the aluminium coating as a potential corrosion inhibitor which can be liberated during sacrificial dissolution of the galvanic layer deposited on the alloy surface. The released inhibitor provides an additional active corrosion protection slowing down the corrosion processes in the defects.     

Electrochemical Behavior of Dental Ni‐Cr Wirolloy Coated with Eco‐friendly Films in Artificial Saliva

The electrochemical corrosion behavior of the non‐precious Ni‐Cr Wirolloy, being used in dentistry, was investigated before and after applying of two types of eco‐friendly coatings, polyvinyl silsesquioxane (PVS) and nano‐hydroxyapatite (nHAP) separately in artificial saliva solution at 37 °C for 14 d of immersion. The study aimed to investigate the effectiveness of the introduced coating films in enhancing the corrosion resistance of the alloy, and in decreasing the leaching of the toxic Ni ions from the alloy into the environment. The electrochemical corrosion investigation methods used are; open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. The evaluated results revealed that the electrochemically coated alloy with PVS. prepared at cathodic potential showed higher corrosion resistance and more stable film compared to that prepared by conventional dip‐coating method. At the same time, the nHAP electrochemically coated film provided the best anti‐corrosion properties over all examined time intervals. The obtained results were confirmed via surface analysis, which assured the formation of the prepared coatings on the alloy surface. Chemical analysis of the corrosion product/solutions showed that the effect of electrochemically deposited nHAP and PVS. polymer films in suppression of Ni ions leaching is similar and slightly higher than that of the chemically coated PVS. one; however, all of them are efficient in decreasing the leaching of the risky Ni ions into the solution.     

空间分辨电化学技术用于研究金属局部腐蚀

综合介绍我们已建立的具有微米空间分辨度的电化学方法,主要包括多种扫描微电极技术,并用于研究金属表面和金属／溶液界面电化学不均一性及局部腐蚀破坏过程。结果表明,这些空间分辨电化学方法的发展及应用,有助于深化对金属表面和金属／溶液界面电化学不均一性,特别是金属局部腐蚀发生、发展过程机理的认识。     

Corrosion behavior of CoCrMoW cast alloy in lactic acid environment for surgical applications

The corrosion behavior of CoCrMoW alloy in lactic acid environment during 168 h of immersion at 37 °C has been studied and assessed by means of electrochemical techniques (open circuit potential (OCP), potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS)). Further, the oxide film thickness formed after immersion and the quantity of ions released have been evaluated by X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma optical spectroscopy (ICP-OES). A good correlation between the results, related to the oxide film thickness, obtained from these experimental techniques was achieved. The research has also shown that the tendency of growing of oxide film becomes slower as the time of immersion is longer. The higher corrosion resistance of CoCrMoW alloy in lactic acid environment is due to the formation of the oxide film highly enriched in Cr(III) on the alloy surface. With a small corrosion rate, e.g. 45 nm year⁻¹, this alloy is characterized as “Perfect Stable” according to ISO 8044/2000. Overall, the present study provides additional evidences with respect to the benefic influence of tungsten on passivity, explained by a higher resistance to pitting corrosion of the CoCrMoW alloy in lactic acid with sodium chloride.     

Electrochemical and microgravimetric characterization of magnetron-sputtered Fe–Cr–Ni–Ta and Fe–Cr–Ni alloy films in neutral and strongly acidic media

The Fe–Cr–Ni and Fe–Cr–Ni–Ta alloy films were deposited on quartz substrates by magnetron-sputtering using targets of AISI 316 stainless steel and in combination with pure tantalum. The conventional melting of the Fe–Cr–Ni–Ta alloy formed is virtually impossible because the melting point of tantalum is higher than the boiling points of the other components. Elemental content of the films was determined by XPS analysis. Corrosion behaviour of both alloy films was studied in 5% NaCl and 10 M HCl by electrochemical quartz crystal microgravimetry (EQCM), electrochemical impedance spectroscopy (EIS) and dc-voltammetry. The corrosion resistance of Fe–Cr–Ni–Ta appeared to be significantly higher than that of Fe–Cr–Ni in both neutral (5% NaCl) and strongly acidic (10 M HCl) media. The Fe–Cr–Ni–Ta specimen exhibited an extremely high corrosion resistance in 10 M HCl, where the corrosion rates were about one order of magnitude lower than those of Fe–Cr–Ni in neutral solution. EQCM measurements in NaCl solution indicated accumulation of corrosion products on the Fe–Cr–Ni–Ta surface, which was evident from a distinctive increase in electrode mass. By contrast, the mass of the tantalum-free alloy film decreased with a constant rate, which indicated alloy dissolution to prevail. The corrosion current calculated from the mass decrease was in good agreement with that derived from voltammetric measurements. The EQCM data showed that the corrosion resistance of the Fe–Cr–Ni–Ta alloy film in 10 M HCl was about two orders of magnitude higher than that of the Fe–Cr–Ni.     

Anodic Behavior of Nickel-Chromium Alloys in Sodium Chloride Solutions: Pitting and Transpassivity

Anodic potentiodynamic and chronoamperometric curves on nickel-chromium alloys (2–50 wt % Cr) are obtained in NaCl solutions at various concentration, pH, and temperature. The dependences of pitting and repassivation potentials on the concentration and temperature are determined for alloy with 20 wt % Cr. The effect of the Cr content and pH on the anodic behavior of the alloys, in particular, the transition from a pitting breakdown of passivity to transpassivation, is shown. Quantitative time dependences of the current in the passive range are obtained and the steady-state values of this current are determined. The corrosion potential of the alloy with 20 wt % Cr is measured. Cathodic voltamograms for passive and chloride-ion-activated surface of the alloy are obtained.     

Corrosion behavior of AA2024-T3 alloy treated with phosphonate-containing TEOS

Protection from corrosion of the aluminum alloy AA2024-T3 coated with a tetraethoxysilicate (TEOS)/aminotrimethyllenephosphonic acid (ATMP) film in a 0.05-mol L⁻¹ NaCl solution was evaluated using electrochemical impedance spectroscopy, scanning electron microscopy, energy disperse spectroscopy, and atomic force microscopy. The present work investigates the influence of different pretreatment procedures of the alloy surface and the ATMP concentration on the corrosion resistance of the coated samples. The undoped sol–gel coatings did not provide adequate corrosion protection. The best corrosion protection was achieved using acetic acid pretreatment and subsequent deposition of an ATMP-modified TEOS film with an optimal concentration of 5.00 × 10⁻⁴ mol L⁻¹ in the deposition bath. The acetic acid pretreatment promotes a decrease in galvanic corrosion and the surface enrichment of aluminum favoring the metalosiloxane and the metal–phosphonic bonds with increasing likely reaction sites, thus promoting the formation of a more homogeneous and compact coating with improved resistance.     

摩擦条件下硫脲对1Cr18不锈钢电化学行为的作用

控制金属材料的腐蚀或磨损有三种方法：１）合理选用耐蚀金属材料（包括开发新材料或对材料进行适宜的表面强化处理;２）改善金属材料服役的介质环境（包括合理使用缓蚀剂）;３）采取电化学保护措施．由于在腐蚀介质中工作的各种摩擦副往往受腐蚀与磨损的协同作用而发生...     

组合法优化Ti掺杂Zn-Al合金薄膜的耐腐蚀性能

应用组合技术, 通过离子束溅射法制备了Zn-Al-Ti合金薄膜材料芯片(其中wAl:wZn=55%:45%(w, 质量分数)), 表征了热处理后薄膜的耐腐蚀性能, 研究了Ti掺杂量对薄膜耐腐蚀性能的影响. 在Ar+5%(φ, 体积分数)H2混合气氛中, 经200 ℃扩散1 h, 再经370 ℃热处理2 h后可以得到高质量的合金薄膜. 通过X射线衍射仪(XRD)和扫描电子显微镜(SEM)分别对热处理后的典型样品进行相结构和形貌表征. 使用电化学方法测试样品的耐腐蚀性能. 结果表明, Ti适量掺杂样品的腐蚀速率明显下降, 其中Ti掺杂量为6.0%(w)的Zn-Al-Ti合金薄膜(94.0%(w) Zn-Al, 其中wAl:wZn=55%:45%)具有最优异的耐腐蚀性能, 其原因在于, Ti适量掺入后晶粒明显细化, 表面更为致密, 且钝化作用增强.