Materials Science and Engineering Commons^™

Study On Electrochemical Behavior Of Copper In Nh3 ·H2O Solution Medium Including K3[Fe(Cn)6] During Cmp, Yue-Hua Hu, Han-Wei He, Ke-Long Huang

Journal of Electrochemistry

Influence of medium pH value and passivator concentrations on the copper passivation and CMP process were studied by electrochemical measurement technologies, relations of the film thickness and tightness with polishing process and polishing rates were investigated. Electrochemical variables influencing polishing process and rates were found out. Electochemical mechanism of polishing processes were explained by corrosion potential and corrosion current density. A recipe of K₃[Fe(CN)₆] as passivator and nano sized γ-Al₂O₃ as abrasives in medium of NH₃·H₂O solution was confirmed reasonable. It is shown that the conditions of polishing process …

Study On The Anticorrosion Of Ld-2 Compound Inhibitor On Reinforcing Steel In Seawater, Rong-Gui Du, Zhou-Cheng Wang, Ruo-Shuang Huang, Rong-Gang Hu, Bing Zhao, Jian-Guang Tan, Chang-Jian Lin

Journal of Electrochemistry

The effect of LD-2 compound inhibitor developed in our laboratory on its anticorrosion action on the reinforcing steel in concrete immersed in seawater was shown in this paper. The corrosion behavior of the reinforcing steel in seawater was studied using electrochemical techniquesand immersion tests. The polarization curve of the reinforcing steel immersed in seawater showedthe free corrosion potential of the steel increased by 0. 220 V (vs. SCE), and the corrosion current decreased by two orders of magnitude by adding 25 g⋅L^-1 compound inhibitor to the seawater. The potentiodynamic anodic polarization curve of reinforcing steel in the seawater with …

Environment-Induced Degradation And Crack-Growth Studies Of Candidate Target Materials: Aaa Task-4 Quarterly (September 1 – November 30, 2001) Report, Ajit K. Roy, Brendan O'Toole

Transmutation Sciences Materials (TRP)

The primary objective of this task is to evaluate the effect of hydrogen on environment-assisted cracking of candidate materials for applications in spallation-neutron-target (SNT) systems such as accelerator production of tritium (APT) and accelerator transmutation of waste (ATW). The materials selected for evaluation and characterization are martensitic stainless steels including HT- 9, EP 823 and 422. The susceptibility to stress corrosion cracking (SCC) and hydrogen embrittlement (HE) of these alloys will be evaluated in environments of interest using tensile specimens under constant load and slow-strain-rate (SSR) conditions. The extent and morphology of cracking of these alloys will further be evaluated …

Analysis Of Corrosion Of Steel By Lead Bismuth Eutectic, John Farley, Dale L. Perry

Transmutation Sciences Materials (TRP)

We examined stainless samples that were exposed to LBE in experiments conducted by the Russians, under contract to Los Alamos. We examined both corroded and uncorroded samples using the Scanning Electron Microscope (SEM), the Energy Dispersive X-Ray (EDAX) Spectroscopy, and the X-ray Photoelectron Spectrometer (XPS). We found that the surface of the corroded sample is covered by oxygen-containing compounds, presumably mostly iron oxide. In samples exposed for shorter times or lower temperatures, we found that some areas were covered by an oxide layer, and some areas was uncovered. We found that the level of Cr in the uncovered area is …

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics: Quarterly Progress Report August 16,2001- November 15, 2001, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The Lead-Bismuth eutectic (LBE) has been determined from previous experimental studies by the Russians and the European scientific community to be a potential material that can be used as a spallation target and coolant for the AAA proposed application.

Properly controlling the oxygen content in LBE can drastically reduce the LBE corrosion to structural steels. However, existing knowledge of material corrosion performance was obtained from point-wise testing with very limited density. The transport of oxygen and corrosion products, their interaction and variation of corrosion/precipitation along the flow are not well understood.

The first subtask of this project involves using a …

Characterization And Electrochemical Investigation Of Boron-Doped Mesocarbon Microbeads Anode Materials For Lithium-Ion Battery, Mao-Hui Chen, Guo-Tao Wu, Guang-Ming Zhu, Jin-Kua You, Zu-Geng Lin

Journal of Electrochemistry

The anodic performances of boron doped and undoped mesocarbon microbeads(MCMBs) were comparatively studied and the structures were characterized by XPS, SEM, XRD and electrochemical measurements. It was found that boron doping samples greatly increased the degree of graphitization and the crystallite size, leading to quite different morphology. Electrochemical discharge/charge cycle tests indicate that lithium intercalation occurred at a little higher potential for the boron doped MCMBs, being attended by greater irreversible capacity loss.

Microstructure And Electrochemical Properties Of The Melt-Spinning Zr0.9Ti0.1(Ni, Co, Mn, V)2.1 Alloy, Ming-Fen Wen, Yu-Chun Zhai, Lian Chen, Min Tong, Hua Zhen, Rong-Jun Ma

Journal of Electrochemistry

The microstructure and electrochemical properties of Zr_0.9Ti_0.1(Ni,Co,Mn,V)_2.1 alloys prepared by both the melt-spinning method and the conventional induction melting were investigated. XRD studies show that Zr_0.9Ti _0.1(Ni,Co,Mn,V)_2.1 alloys at as-cast, melt-spinning and annealing are all face center cubic structure with C₁₅ laves phase, the higher the melt-spinning rate, the more the amorphous content. The electrochemical measurements show that melt-spinning alloys have better active behavior, low discharge capacity (< 280 mAh/g); but after annealed, the alloys are activated completely with 30 cycles, the capacities about 340 mAh/g are higher than those of as-cast and melt-spinning alloys; the annealec alloys have a better cycle stability than that of as-cast alloy, and the higher the melt-spinning rate is, the more stable the alloy becomes; at 300 mAh/g current density, the capacity of annealed 40 m/s alloy is up to 85% of the maximum capacity after 800 cycles, the capacity decay rate is about 6.9%.

The Coulostatic Method For Evaluating Corrosion In Reinforced Concrete, Yong-Tao Zhao, Jian-Hua Wu, Chang-Jiu Zhao

Journal of Electrochemistry

In the present paper, the application of the coulostatic method to the corrosion of steel in concrete was reviewed. By comparing with other electrochemical techniques, the results obtained in the previous work reveal that the coulostatic method is an interesting alternative to the usual procedures for estimation of corrosion rate, and is better than them in some respects. The main advantages are as follows. The signal to be used can be instantaneous and as small as desired, so the electrode is minimally perturted during the measuring process. In addition, it is as rapid and quantitative, and at least as reliable …

Charge/Discharge Characteristics And Structural Changing Of Spherical β-Ni(Oh)2 Prepared From Different Nickel Salt, Shu-Ting Yang, Yan-Hong Yin, Hong-Jun Chen, Jun-Hua Jia, Ming-Chum Zhang, Li Ding

Journal of Electrochemistry

Spherical β-Ni(OH)₂ was prepared from different nickel salt by homogeneous complexing precipitation method. Its charge/discharge and cyclic voltammetry properties were studied. The authors found that there are many differences in the electrochemical properties of the prepared Ni(OH)₂.The specific capacity, cycling life and the discharging plateau of the material prepared from NiSO₄ were superior to those of the material prepared from Ni(NO₃)₂. The reasons of the differences were analyzed by XRD and FTIR measurements, which will become abasis for the selection of raw materials.

In Situ Ftir Reflection Spectroscopy Of Bioelectrode, Sa-Ying Dong, Guang-Yu Zhao, Yuzhu Gao, Guang-Zhang Chen, Ming-Xiang Lv

Journal of Electrochemistry

In situ FTIR reflection spectroscopy was used to study mediated enzyme electrode and immunoelectrode. We determined and analyzed IR characteristic spectra of GOD and glucose by the use of potential difference spectra and single beam subtractive spectra. At last, we explored the IR absorption characters of enzyme-immunoelectrode.

The Influence Of Membrane Resistance On The Electrochemical Behavior Of Gold Electrode Modified By Self-Assembled Monolayer, Xiao-Li Cui, Zhi-Yu Jiang

Journal of Electrochemistry

The electrochemical behavior of gold electrode modified by hexadecanethiol self-assembled monolayer (SAM) in the solution of Fe(CN)₆^3-/Fe(CN)₆^4- was investigated by cyclic voltammetry and ac impedance spectroscopy. The pinhole-free SAM-modified gold electrode has excellent blocking properties to the interfacial electron transfer from redox couple in solution to the substrate. The current increased exponentially with the overpotential at the high potential region. A good linear relationship between ln(I/η) and η_1/2 was observed. A model system Au/SAM/Hg was constructed and its I～V curve was measured. Similar phenomena were observed. There was also a linear relationship between ln(I/V) …

Codeposition And Corrosion Resistance Of Nickel-Cerium-Phosphorus Amorphous Alloys, Jiang Liu, Xiong Jiang, Lin-Cai Jiang, Ze-Shan Zhu

Journal of Electrochemistry

The possibility of electrodeposition of rare earth alloys from aqueous bath was investigated using varous techniques such as linear potential sweeping, cyclic voltammetry, electrodepositon at constant potential etc. The Ni-Ce-P alloys with different cerium content were electrodeposited from a weakly acidic solution containing CeCl₃, NaH₂PO₂ and so on the crystal structure and component were characterized by XPS, AES, XRD and SEM observation. The codeposits were found to be more highly corrosion resistent than that of Ni-P amorphous alloys by measuring polarization resistance and corrosion potential. The effects of codeposition conditions on the corrosion resistance were …

Current Oscillations In The System Of Carbon Steel/Phosphoric Acid/Platinum, Shao-Yuan Shi, Jin-Ping Wu, Jing Liu, An Lin

Journal of Electrochemistry

The periodic,aperiodic, chaotic and mixed-mode oscillations can occur in the process of the anodic electrodissolution of carbon steel in the solution of dilute phosphoric acid. More plentiful dynamic behaviors can be found in this system compared with the system of Fe/H₃PO₄/Pt.

The Activation Mechanism Of Al Alloys With Tin And Gallium In Alkaline Electrolytes, Zhen-Ya Li, Ling Yi, Zhi-Hui Liu, Lin Yang, Jing-Xin Su, Yan-Ying Chen

Journal of Electrochemistry

The major reason for Al-anode's activation is that Ga and Sn deposit on the aluminum surface and form activated points. The Al-Sn and Al-Ga binary alloys can't be activated in alkaline medium. During the dissolution of the Al-Sn-Ga ternary anode, Sn and Ga dissolve into the solution and transform into ions. After the Sn ions deposit on the surface of Al-anode, the Ga ions will deposit on Sn. The higher activation of the polynary alloy anode is caused by much more new activated points composed of Ga-Sn alloy being continually formed. Ga- Sn alloy with low melting point deposited on …

Determination Of Hydrogen Diffusion Coefficient In Metal Hydride Electrode With Electrochemical Impedance Spectroscopy, Xian-Xia Yuan, Nai-Xin Xu

Journal of Electrochemistry

Electrochemical impedance spectroscopy was employed to determine the hydrogen diffusion coefficient in MlNi _3.75Co _0.65 Mn_0.4Al_0.2 metal hydride electrode with various states of charge (SOC) at room temperature and with 50% SOC at various temperatures. It was found that hydrogen diffusion coefficient in this electrode decreases with the increase in SOC at ambient temperature, and for the electrode with 50% SOC, hydrogen diffusion coefficient increases with the increase of temperature and the activation energy for hydrogen diffusion in it is 35 kJ/mol.

A New Method For Impregnating Nafion Solution Into The Electrode Of Pemfc, Qian Tang, Ming Han, Bao-Lian Yi, Zhi-Yin Lin

Journal of Electrochemistry

We have developed a new method for impregnating Nafion solution into the catalyst layer of homemade hydrophobic electrode using capillary process. Those electrodes show better performance and higher utilization of catalyst (detected by CV and TEM) than traditional spray method in PEMFC. According to the results of SEM photograph and linear-analysis of sulfur and platinum for the electrode cross-section, we can conclude that the resin is uniform in the catalyst layer and has almost same depth as catalyst in the impregnated electrode. While in traditional method resin is not uniform in the catalyst layer and penetrates into the diffusion layer, …

Analysis Of Corrosion Of Steel By Lead Bismuth Eutectic, John Farley, Dale L. Perry

Transmutation Sciences Materials (TRP)

The goal is to achieve a basic understanding of the corrosion of stainless steel by Lead Bismuth Eutectic (LBE), which has been proposed for use in the transmuter as both a coolant and as a sputtering target.

Modeling Corrosion In Oxygen Controlled Lbe Systems With Coupling Of Chemical Kinetics And Hydrodynamics, Samir Moujaes, Yitung Chen

Transmutation Sciences Materials (TRP)

The proposed work will combine chemical kinetics and hydrodynamics in target and test-loop lead-bismuth eutectic (LBE) systems to model system corrosion effects. This approach will result in a predicative tool that can be validated with corrosion test data, used to systematically design tests and interpret the results, and provide guidance for optimization in LBE system designs. The task includes of two subtasks. The first subtask is to try to develop the necessary predictive tools to be able to predict the levels of oxygen and corrosion products close to the boundary layer through the use of Computational Fluid Dynamics (CFD) modeling. …

Hydrogen-Induced Embrittlement Of Candidate Target Materials For Applications In Spallation-Neutron-Target Systems, Brendan O'Toole, Ajit K. Roy

Transmutation Sciences Materials (TRP)

The purpose of this project is to evaluate the effect of hydrogen on cracking of candidate target materials for applications in spallation-neutron-target (SNT) systems such as accelerator production of tritium (APT) and accelerator transmutation of waste (ATW). The test materials will undergo appropriate thermal treatments prior to being hydrogen-charged by potentiostatic cathodic polarization technique in a simulated aqueous environment at different temperatures of interest. The specimens, upon completion of testing, will be metallographically examined. Further, the scanning electron microscopy (SEM) will be used to determine the extent and nature of cracking in the specimens tested. The thrust of the proposed …

Performance Of Proton Exchange Membranefuel Cell With Co/H2 Fuel, Hong-Mei Yu, Zhong-Jun Hou, Bao-Lian Yi, Ke-Wan Bi, Jing-Xin Zhang, Zhi-Yin Lin, Ming Han

Journal of Electrochemistry

Fuel of proton exchange membrane fuel cell(PEMFC) mostly comes from reformatecontains CO which will poison the fuel cell electrocatalyst. The effect of CO on the performance of PEMFC was studied in this paper. The results of the experiment show that when CO is fed inPEMFC ,the cell voltage will be decreased violently,then it will become steady with some vibration. The poison will become more serious with higher CO content and weaker at higher temperature. The adsorption of CO on the electrocatalyst is reversible. The PtRu electrocatalyst is moresuitable for the electrocatalysis of CO/H₂ than Pt electrocatalyst.

Atmospheric Corrosion Of Steels In China, Cai-Feng Liang

Journal of Electrochemistry

Data of eight year atmospheric exposures of 17 steels at 7 sites in China were analyzed. The result showed that the most detrimental pollution is sulfur dioxide and chloride ion for corrosion of carbon steels and low alloy weathering steels. This is in accordance with the common knowledge.The effect of sulfur dioxide is serious in the first few years and becomes weak obviously in the later years. The environment factor of humid hot is much more important in long run than the ordinarily acknowledged humidity, pollution for non weathering steels,although it is not obvious in the beginning. If pollution were …

Properties Of Metallized Polyo-Toluididemembrane Modified Electrode, Li-Zong Dai, Yi-Ting Xu, Hui-Huang Wu

Journal of Electrochemistry

The platinum particles were electrodeposited on poly(o-toluidide), POT, modified electrode, and the surface configuration and crystal orientation of Pt particles were investigated by SEM and XRD. At the same time the oxidation of isopropanol on platinized POT modified electrode was studied. The results indicate that Pt particles deposite towards preferred-orientation; moreover the increase in polymer electroactivity due to proton doping affects the dimension and graininess of deposited Pt particles. At the metallized polymer electrode the oxidation of isopropanol can occur in POT electroactive potential region, however at the more positive than 0.70 V (SCE) potential where POT loses redox activity …

Galvanic Corrosion Of Tin-W Electro-Couple During Tungsten Chemical Mechanical Polishing, Xuan Cheng, Chang-Jian Lin

Journal of Electrochemistry

Chemical mechanical polishing (CMP) is a process whereby mechanicaland chemical forces are combined to remove material from a wafer and polish it to a flatsurface. Tungsten CMP is an important prcess to gain the global planarity of siliconwafers with tungsten (W) plugs. Tungsten is actually deposited on a thin adhesive layerof titanium nitride (TiN) on silicon. When close to the final stage of polishing, TiN and W will be simultaneously exposed to the polishing chemistry, forming a galvaniccouple. The corrsion of TiN and W couple will result in different polish rate.

Electrochemical Behavior Of Tinicu Shape Memry Alloy In Simulated Body Fluid, Cheng-Hao Liang, Hong-Yan Sui

Journal of Electrochemistry

The study of TiNiCu shape memory alloys (SMA) in Hank's simulated body fluidwas carried out. The results showed that narrow passive range was found in acid environment andactive anodic dissolution was discovered at 100~150 mV vs SCE on anodic polarization cure ofTiNiCu SMA. Temperature had little effect on anodic polarization. With the decrease of pH andthe increase of Cl^- concentration ,pitting corrosion potential (E_b) shifted negatively. The electrochemical capability of TiNiCu SMA was inferior to that of TiNi SMA. Observations by means ofXRD and SEM indicate that TiNiCu SMA is not in single crystal structure, which caused …

Study Of The Oxidation Dynamics Of Tizro2 Metal-Ceramics, Wen-Chao Li, Li-Dong Teng

Journal of Electrochemistry

The oxidation dynamics of hot-pressed Ti-ZrO₂ metal-ceramics with the compositionof 50 vol.% Ti and 50 vol.% ZrO₂ has been studied.Thermodynamic analysis shows that Ticould react with O₂ but not with N₂ in the oxidizing process of TiZrO₂ composites at 0.1 MPa air. The oxidation dynamic behavior of Ti-ZrO₂ composites is analogous to that of pure Ti. Theactivation energy for the oxygen diffusion in Ti-ZrO₂ composites is higher than that in Ti solutions, for the presence of ZrO₂ restrains the oxygen diffusion in Ti-ZrO₂ composites. At early stagethe oxidation of Ti-ZrO_{2 …}

Preparation And Properties Of Separator For Lithium-Ion Battery, Xu-Mei Ren, Feng Wu, Chuan Wu, Han-Jun Li, Xue-Jie Huang

Journal of Electrochemistry

Lithium-ion batteries are well adapted to the new multimedia applications. PP/PE based microporous film is commonly used as separator in commercial lithium ion batteries. Herewe report a microporous film which is superior to the commercial available separator. The microporous PVDF polymer separators were prepared by the phase inversion process. The pore size of the separator is Φ 7 μm , and it's porosity is 75 %. The membrane in LiPF₆-EC/DEC showedhigh ionic conductivity (above 10^-3 S/cm at room temperature), and good mechanical properties(10³ kg/cm²). The half-cells consisted of Li/PVDF separator/MCMB showed excellent cyclingcharacteristics and …

The Effect Of Calcium On The Properties Of Molybdenum Nitride Electrode, Yun-Gui Zhu, Xue-Liang Li, Dao-Rong Lu, Jian-Bo He, Ji-Huai Xia

Journal of Electrochemistry

The effect of calcium on the properties of molybdenum nitride film electrode wasstudied by using XRD, SEM and cyclic voltammetry. The results show that the specific electriccapacity and the voltage operating range of electrode vary with the concentration of additive in thedipping solution. At the optimum concentration of additive in the dipping solution, the specificelectric capacity of the electrode is 2.1 times as large as that of the electrode prepared in the dipping solution without additive, and the voltage operating range of electrode is increased by 0.11 V. The active mechanism of calcium on the properties of film electrode suggested …

Corrosion Behavior Of Titanium In Fgd System, J-C Lin, T-L Chang, C-T Dung, S-L Lee, S-D Chyou, S-D Guo

Journal of Electrochemistry

In-situ corrosion test of titanium in flue gas desulfurization(FGD) system has been studied. Specimens of commercial Ti alloy have been put in four different locations (i. e , cooler, pre-scruber, absorber and heater) of the FGD system for 271 days. The corrosion rate is very low (i.e.<1 mpy) in all locations. Almost no corrosion can be found in the prescruber(0 mpy), but a sensible corrosion rate is estimated in the heater (0.58 mpy). Examination through SEM, all the specimens are subject to pitting corrosion except those in the prescruber. ESCA analysis indicates that the surface film for the specimen in prescruber is calcium carbonate, but titanium nitrate for the specimen in heater. Cyclic anodic potentiodynamic polarization (CAPP) of titanium in aerated and deaerated green solution provides an interpretation on the corrosion behavior of the titanium in the FGD system.

Performance Of A Direct Methanol Fuel Cell, Zhao-Bin Wei, Jian-Guo Liu, Ya-Guang Jiao, Wei-Jiang Zhou, Wen-Zhen Li, Li-Kang Chen, Qin Xin, Bao-Lian Yi

Journal of Electrochemistry

A direct methanol fuel cell with 9cm² active area consists of Pt-Ru/C anode ,Pt/Ccathode and Nafion 115 membrane. The effect of operating conditions: methanol solution concentration, oxygen pressure and cell temperature on the cell performances was investigated. The results show that performance of single cell was enhanced by increasing oxygen pressure and celltemperature ,and a maximum power density 75 mW/cm² was obtained in the range of 250-300mA/cm² current density, 0.2 MPa oxygen pressure, 1.0 mol/L methanol concentration and 75 ℃ cell temperature. When cell operating at room temperature, a relatively low, but a stable performance of cell …

The Effect Of Preparation Condition On The Photoelectrochemical Performance Of Both The Pani Film And Tio2-Pani Composite Film On Au, Huai-Guo Huang, Hong-Ping Zhang, Zhi-Xin Zheng, Yan-Yan Xi, Ling-Ling Wu, Zhong-Hua Lin

Journal of Electrochemistry

Both the PANI (polyaniline) film and TiO₂-PANI composite film on the PATP(paminothiophenol)/Au substrate were obtained under different preparation condition by electrochemical methods, and their photoelectrochemical performances were alo studied. The resultsshowed that the photoelectrochemical performances of the films depend deeply on the comditionsof preparation. The self-assembling of PATP favors the adhesion of PANl. The partially-oxidizedPANI has a greater photoelectrochemical response than that of the reduced PANI and oxidized PANl. There is an optimum of film thickness for the photoelectrochemical performance of PANI film. Heat treating is in favor of the photoelectrochemical performance of TiO₂, but decreases …