Electrodeposition

دسترسی آزاد مقاله

1 - Effect of Formaldehyde on Pulsed Electro-Plated Nickel-Alumina Nanocomposite Coatings
S Mirzamohammadi M Velashjerdi A Anbarzadeh

Metal-based nanocomposite coating prepared by plating method can exhibit unique mechanical, chemical, and physical features which have led to their extensive application in various high-tech industries. Nickel-based nanocomposite coatings can pose far lower pollution to چکیده کامل

Metal-based nanocomposite coating prepared by plating method can exhibit unique mechanical, chemical, and physical features which have led to their extensive application in various high-tech industries. Nickel-based nanocomposite coatings can pose far lower pollution toward the environment and related staff as compared with chromium-based ones. In this research, a novel compound was developed to coat nickel-alumina nanocomposite by adding formaldehyde to the plating bath. The concentration of alumina nanoparticles (NPs) in the plating bath was 10 g/L. The nickel-alumina nanocomposite coatings were prepared by a pulsed electrical current under ultrasound turbulence in the plating bath. Two Ni bathes in combination with Watt’s compound were used with and without formaldehyde addition. Before plating, the zeta potential of alumina NPs was measured in the two different baths. After plating, the cross-section of the coatings and the alumina content participated in the coating, as well as the coating morphology, were analyzed by scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDX). Based on the results, incorporation of formaldehyde into the Watt’s solution increased the zeta potential of the nanoparticles from -4.1 to +30.5 mV; consequently, the nanoparticle content of the coatings enhanced from 4.6 to 8.5 vol.%. پرونده مقاله

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2 - Produce of Biodegradable Porous Mg-Zn Scaffold via Powder Metallurgy and Coated with Nano HAP Synthesized by Electrodeposition Process
Z.S. Seyedraoufi Sh. Mirdamadi

Mg is considered promising degradable material for tissue engineering applications because of good biocompatibility, corrosion and mechanical properties. In the present work, biodegradable porous Mg-1 wt% Zn scaffold was produced by powder metallurgical process and then چکیده کامل

Mg is considered promising degradable material for tissue engineering applications because of good biocompatibility, corrosion and mechanical properties. In the present work, biodegradable porous Mg-1 wt% Zn scaffold was produced by powder metallurgical process and then nano hydroxyapatite (HAP) coating with composition of Ca10(PO4)6(OH)2 on the scaffold was synthesized by pulse electrodeposition and alkali treatment processes to increase the corrosion resistance of the substrate. The results showed that the as-deposited coating consists of HAP, CaHPO4.2H2O (DCPD) and Ca8H2(PO4)6.5H2O (OCP) with plate-like and needle-like morphologies and the post-treated coating was composed of needle-like structure of nano HAP developed almost perpendicularly to the substrate .Electrochemical tests indicated that the corrosion current density reduced from2.731×10-3 to 4.98×10-5 A.cm-2 and the corrosion potential of scaffold increased from -1.451 to -1.37 V. This study revealed that electrodeposition of HA coating is a useful approach to improve the corrosion resistance of porous Mg-Zn scaffold in SBF and to develop Mg-based degradable implants. پرونده مقاله

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3 - The effect of saccharin on microstructure and corrosion behavior of nanocrystalline nickel thin films in alkaline solution
Behrooz Shayegh Nima Zaghian

In this study the effect of crystallite size reduction and microstructure on the electrochemical corrosion behavior of nanocrystalline nickel (NC Ni) were investigated using Tafel polarization and electrochemical impedance spectroscopy (EIS) measurements in 10 wt.% NaOH چکیده کامل

In this study the effect of crystallite size reduction and microstructure on the electrochemical corrosion behavior of nanocrystalline nickel (NC Ni) were investigated using Tafel polarization and electrochemical impedance spectroscopy (EIS) measurements in 10 wt.% NaOH. NC Ni coatings were produced by direct current electrodeposition using chloride baths in presence and absence of saccharin as a grain refining agent. The crystallite size of NC surface coatings was calculated and analyzed by X-ray diffractometry (XRD). Field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM) were used to study coatings microstructure. The chemical composition of NC surfaces was determined using X-ray energy dispersive spectroscopy (EDS). Our results showed Saccharin decreased the crystallite size but increased the grain size. In addition, corrosion resistance of NC Ni in presence of saccharin increased, which is ascribed to the formation of more stable and protective film. The behavior of passive film growth and corrosion were discussed. پرونده مقاله

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4 - Addition of Mo in the Zn based alloy coating in the citrate solution and investigation of its corrosion behavior
Mahdi Omidi Mahdi Yeganeh Arash Etemad Mohammad Reza Rostami Mohammad esmaeil Shafie

In this work, Zn-Co-Mo coatings were electrodeposited on mild steel substrate from a citrate solution at current densities of 5, 7.5 and 10 mA.cm-2 and pH values of 4.5, 5, and 5.5. The coated samples were studied by scanning electron microscope and potentiodynamic pola چکیده کامل

In this work, Zn-Co-Mo coatings were electrodeposited on mild steel substrate from a citrate solution at current densities of 5, 7.5 and 10 mA.cm-2 and pH values of 4.5, 5, and 5.5. The coated samples were studied by scanning electron microscope and potentiodynamic polarization. The corrosion behavior of the coatings was related to the molybdenum content and formation of local anodes and cathodes. According to the results, a distinct range of current and pH was recognized to provide high quality and corrosion resistant coatings. The percentage of molybdenum as an alloying element plays an important role in the improvement of the corrosion properties of the coating. The formed coating at pH of 5.5 with 13 wt. % Mo showed the lowest corrosion current density with a value of 0.5 µA.cm-2.The molybdenum coating also showed a passive-like behavior in the anodic region due to the presence of molybdenum in the coating composition. پرونده مقاله

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5 - Fabrication of anodic aluminium oxide template and the generation of magnetic Co nanowires within it
masoud soltani Reihane Aliramezani saeid akhavan Zeinab Erfani Gahrouei mohammad noormohammadi

Among nanostructured materials, magnetic nanowires have been heeded because of their high shape anisotropy and their easy fabrication methods. Electrochemical deposition on the anodic aluminium oxide (AAO) is one of the best methods to grow different nanowires. In this چکیده کامل

Among nanostructured materials, magnetic nanowires have been heeded because of their high shape anisotropy and their easy fabrication methods. Electrochemical deposition on the anodic aluminium oxide (AAO) is one of the best methods to grow different nanowires. In this paper, the AAO was fabricated on the 1100 Al alloy substrate by hard anodizing in 0.3 M oxalic acid solution. Then, a barrier layer thinning process was carried out for the electrodeposition process. A pulsed electrodeposition process was used to fill the nano-pores. According to this method, cobalt nanowires were grown in the nano-holes. Structural, crystalline, and magnetic properties of the samples were evaluated using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM), respectively. The results showed that nanowires have a diameter of 87 nm and crystalline structure with crystalline plates in directions (100), (002), and (110). A coercivity value of 600 Oe was obtained for nanowires, which is several times larger than cobalt bulk. پرونده مقاله

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6 - Influences of Bath Stirring Rate on Synetics of Nano Composite Ni-SiC-Gr Coatings on St37 via Electrodeposition Process
M Rostami R Ebrahimi-Kahrizsangi A Saatchi

In this study, electrochemical deposition of Ni-SiC-Gr nano composites was studied. The Watts bath was used for electrodeposition. The SiC and graphite powders were suspended in the electrolyte and stirred. The effects of changes in bath stirring rate on the composite c چکیده کامل

In this study, electrochemical deposition of Ni-SiC-Gr nano composites was studied. The Watts bath was used for electrodeposition. The SiC and graphite powders were suspended in the electrolyte and stirred. The effects of changes in bath stirring rate on the composite coating were investigated. The X-Ray diffraction (XRD), scanning electron microscopy (SEM) and field emission scanning electron microscopy (FE-SEM) methods were used to characterize the micro structure of deposited layer. The results showed that the micro-hardness at the first stage increases with increases in stirring rate value. The coating that precipitated at 500 rpm showed maximum hardness. Analysis of microstructure with SEM showed a homogeneous and uniform distribution of elements in the coated layer. The optimum condition for electrodeposition were as: pH=4.2, current density= 4A/dm2, stirring rate =500 rpm and 45˚C. پرونده مقاله

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7 - Comparative evaluation of niobium surface preparation methods for electrodeposition
H Nasiri Vatan M.R Mohammadshafiee

To find a suitable treatment in the preparation of Nb surface for platinum electrodeposition, different methods such as thermal oxidation, anodic oxidation, mechanical roughening, and mechanical roughening with subsequent anodic etching were examined. X-ray photoelectro چکیده کامل

To find a suitable treatment in the preparation of Nb surface for platinum electrodeposition, different methods such as thermal oxidation, anodic oxidation, mechanical roughening, and mechanical roughening with subsequent anodic etching were examined. X-ray photoelectron spectroscopy was used to study the chemical composition of depth analysis of the surface. Moreover, in order to examine the morphology and surface roughness, the samples were analyzed by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The results showed that the most appropriate method for niobium surface preparation is mechanical roughening by shot blasting or abrading with emery and then anodic etching at the current density of 200 A/m2 for 40 min. in a solution containing 95% methanol, 2.5% hydrofluoric acid, and 2.5% hydrochloric acid at the temperature of 35 °C. پرونده مقاله

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8 - One-step cathodic electro-synthesis and characterization of dextran coated magnetite nanoparticles
Mustafa Aghazadeh Isa Karimzadeh

10.22034/jna.2017.542007.1018

In this research, a simple and efficient cathodic electrochemical deposition (CED) route was developed for the preparation of magnetite nanoparticles (NPs) in an aqueous media. The surface of magnetite NPs was also coated for the first time via an in situ procedure duri چکیده کامل

In this research, a simple and efficient cathodic electrochemical deposition (CED) route was developed for the preparation of magnetite nanoparticles (NPs) in an aqueous media. The surface of magnetite NPs was also coated for the first time via an in situ procedure during the CED process. In this method, initially, the Fe3O4 NPs (with size ~10 nm) were prepared from the Fe2+/Fe3+ chloride bath through CED process. Then, dextran as the coating agent was coated on the surface of Fe3O4 NPs during the CED process. The prepared NPs were characterized by different techniques such as XRD, FE-SEM, TEM, IR, TGA, DLS and VSM. The XRD results proved the pure magnetite i.e. Fe3O4 crystal phase of the prepared samples. Morphological observations through FE-SEM and TEM revealed particle morphology with nano-sizes of 8 nm and 12 nm for the naked and dextran coated NPs, respectively. The dextran coat on the surfaces of NPs was confirmed by FT-IR and DSC-TGA analyses. The average hydrodynamic diameters of 17 nm and 54 nm were measured from DLS analysis for the naked and dextran coated NPs, respectively. The magnetic analysis by VSM revealed that prepared NPs have superparamagnetic behavior i.e. Ms= 82.3 emu g–1, magnetization Mr= 0.71 emug–1 and Ce= 2.3 Oe for the naked NPs, and Ms= 43.1 emu g–1, Mr =0.47 emu g–1 and Ce=0.81Oe for the dextran coated NPs. These results implied that this electrochemical strategy can be recognized as an effective preparation method of polymer coated Fe3O4 NPs. پرونده مقاله

دسترسی آزاد مقاله

9 - One-step Cathodic Electrochemical Synthesis and Characterization of Dextran Coated Magnetite Nanoparticles
Mustafa Aghazadeh Isa Karimzadeh

10.22034/jna.2017.539366

In this research, a simple and efficient cathodic electrochemical deposition (CED) route wasdeveloped for the preparation of magnetite nanoparticles (NPs) in an aqueous media. Thesurface of magnetite NPs was also coated for the first time via an in situ procedure during چکیده کامل

In this research, a simple and efficient cathodic electrochemical deposition (CED) route wasdeveloped for the preparation of magnetite nanoparticles (NPs) in an aqueous media. Thesurface of magnetite NPs was also coated for the first time via an in situ procedure during theCED process. In this method, initially, the Fe3O4 NPs (with size ~10 nm) were prepared from theFe2+/Fe3+ chloride bath through CED process. Then, dextran as the coating agent was coatedon the surface of Fe3O4 NPs during the CED process. The prepared NPs were characterizedby different techniques such as XRD, FE-SEM, TEM, IR, TGA, DLS and VSM. The XRD resultsproved the pure magnetite i.e. Fe3O4 crystal phase of the prepared samples. Morphologicalobservations through FE-SEM and TEM revealed particle morphology with nano-sizes of 8nm and 12 nm for the naked and dextran coated NPs, respectively. The dextran coat on thesurfaces of NPs was confirmed by FT-IR and DSC-TGA analyses. The average hydrodynamicdiameters of 17 nm and 54 nm were measured from DLS analysis for the naked and dextrancoated NPs, respectively. The magnetic analysis by VSM revealed that prepared NPs havesuperparamagnetic behavior, i.e. Ms=82.3 emu g–1, magnetization Mr=0.71 emug–1 and Ce=2.3Oe for the naked NPs, and Ms=43.1 emu g–1, Mr=0.47 emu g–1 and Ce=0.81Oe for the dextrancoated NPs. These results implied that this electrochemical strategy can be recognized as aneffective preparation method of polymer coated Fe3O4 NPs. پرونده مقاله

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10 - A Nickel Sublayer: An Improvement in the Electrochemical Performance of Platinum-Based Electrocatalysts as Anodes in Glucose Alkaline Fuel Cells
Behnam Moeini Masoumeh Ghalkhani Tahereh G. Avval Matthew R. Linford Rasol Abdullah Mirzaie

Platinum–nickel electrocatalysts supported on the modified carbon paper (MCP) were prepared by electrodeposition. Here, various procedures were applied for the electrodeposition of nickel and platinum particles, separately or simultaneously, on the surface of the چکیده کامل

Platinum–nickel electrocatalysts supported on the modified carbon paper (MCP) were prepared by electrodeposition. Here, various procedures were applied for the electrodeposition of nickel and platinum particles, separately or simultaneously, on the surface of the MCP as an anode electrode for glucose alkaline fuel cells. The establishment of the best procedure for this fabrication is the main goal of this work. The obtained electrocatalysts were characterized by cyclic voltammetry, linear sweep voltammetry, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The results showed that the Pt/Ni electrocatalyst, electrodeposited from two separate solutions containing Ni and then Pt ions, has excellent electrocatalytic activity for the glucose oxidation reaction (GOR). On the other hand, the Pt/Ni/MCP electrode showed satisfactory repeatability when subjected to continuous cycling and less concentration polarization in the oxidation region of GOR (from -1 to 0.6 V vs. SCE). Also, the Pt/Ni/MCP electrode showed a significant increase in the exchange current density (0.95 mA cm-2) that accelerates the kinetics of the glucose oxidation reaction.These results indicate that modification of the catalyst layer structure in the present work is the most promising approach to achieve low-cost and efficient catalysts for use in glucose alkaline fuel cells. پرونده مقاله

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11 - Increasing the Adsorption of Reinforcement Alumina Nanoparticles in Ni-alumina Nanocomposite Coatings by Using Methanol Organic Solvent
صادق میرزامحمدی حمید خورسند محمود محمود علی اف خضرایی

To enhance the mechanical properties in Ni-alumina nanocomposite coatings, it is necessary to increase the amount of alumina nanoparticles participation in nickel matrix. The aim of this study is the compassion investigation of Ni-Al2O3 nanocomposite coatings’ emb چکیده کامل

To enhance the mechanical properties in Ni-alumina nanocomposite coatings, it is necessary to increase the amount of alumina nanoparticles participation in nickel matrix. The aim of this study is the compassion investigation of Ni-Al2O3 nanocomposite coatings’ embedded nanoparticles affected by methanol addition to the electrolyte. In this investigation the composition of electrolyte was modified by adding methanol organic solvent. The coating were produced by pulse current and under ultrasonic agitation .After the electroplating process, the coatings’ cross sectioned and the amount of incorporated alumina nanoparticles and the morphology of each coating was analyzed by Energy X-ray spectroscopy (EDX) coupled with an Scanning Electron Microscopy (SEM). The results showed that with adding the methanol organic solvent to the Watt’s solution the zeta potential of the nanoparticles increased from -4.1mV to +24.5mV and subsequently, the content of alumina reinforcement nanoparticles increased from 4.6vol. % to 11vol. %. It has been assumed that methanol surfactant may act as a surface agent that affected the hydrated layer on the nanoparticles and it promoted the co-deposition of nano alumina particles with nickel. پرونده مقاله

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12 - Utilization of electrodeposition on a graphite probe modified with palladium in determination of lead by graphite furnace atomic absorption spectrometry in water and environmental samples
Ahmad Rouhollahi Reza Moradkhani Hamid Shirkhanloo Jahan B. Ghasemi

In this work a rapid and selective procedure for separation and preconcentration of lead(Pb2+) before determination by electrothermal atomic absorption spectrometry (ETAAS) wasdeveloped. The procedure is based on the electrodeposition on a graphite probe modified withpa چکیده کامل

In this work a rapid and selective procedure for separation and preconcentration of lead(Pb2+) before determination by electrothermal atomic absorption spectrometry (ETAAS) wasdeveloped. The procedure is based on the electrodeposition on a graphite probe modified withpalladium. The lead was deposited from acetate buffer solution at pH 5.5. Various parameters,such as pH of solutions, deposition potential, buffer concentration, stirrer speed, time ofdeposition and temperature program, were optimized. After optimization of the conditions,detection limit 17 ng L–1 by 3 σ, and enrichment factor 61 were achieved for 2 minelectrodeposition time and improved as deposition time was increased. Linearity of calibrationwas kept between 0.05-0.50 μg L–1 with a correlation coefficient of 0.9979 and suitableprecision, R.S.D. % = 5.1 (n = 8). Samples were digested completely in a closed microwavedigestion system using only perchloric acid, and interference owing to various cations was alsoinvestigated. The procedure was successfully applied to determine the presence of lead in rice,radish, okra, onion and water samples. پرونده مقاله

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13 - اثر متغیرهای رسوب دهی بر فرایند رسوب الکتریکی پالسی کامپوزیت نانوساختار FeNi-WC
آمنه وحیدیان علی سعیدی محمد علی گلعذار

نیاز روزافزون به مواد مغناطیسی در صنعت منجر به تولید کامپوزیت آلیاژهای مغناطیسی آهن-نیکل با ذرات سرامیکی شده است. در این تحقیق کامپوزیت نانوساختار FeNi-WC به روش رسوب‌دهی الکتریکی پالسی تولید شد. همچنین اثر عواملی چون pH و چگالی جریان و مقدار تقویت کننده بر ترکیب شیمیای چکیده کامل

نیاز روزافزون به مواد مغناطیسی در صنعت منجر به تولید کامپوزیت آلیاژهای مغناطیسی آهن-نیکل با ذرات سرامیکی شده است. در این تحقیق کامپوزیت نانوساختار FeNi-WC به روش رسوب‌دهی الکتریکی پالسی تولید شد. همچنین اثر عواملی چون pH و چگالی جریان و مقدار تقویت کننده بر ترکیب شیمیایی و مورفولوژی نمونه‌ ها مورد بررسی قرار گرفت. همچنین برای بررسی مورفولوژی از میکروسکوپ الکترونی روبشی (SEM)، و تعیین عناصر موجود و محاسبه درصد وزنی آن‌ها از آنالیز پراش سنجی انرژی (EDS) و بررسی ساختار نمونه از پراش پرتو ایکس (XRD) استفاده گردید. نتایج نشان داد با افزایش pH، به مقدار کمی نیکل افزایش و آهن کاهش یافت و منجر به تغییر مورفولوژی از کروی به ستاره‌ای گردید. به دلیل اهمیت صرفه‌جویی در انرژی اثر این متغیرها بر پارامترهای راندمانی چون بازده جریان و انرژی مصرفی ویژه نیز مطالعه شد. مشاهده شد که با افزایش pH، بازده جریان افزایش و انرژی مصرفی ویژه کاهش یافت. افزایش چگالی جریان نیز بازده جریان را کاهش و انرژی مصرفی ویژه را افزایش داد. به طور کلی در چگالی جریان های بیشتر (mA/cm2 100) و مقدار تقویت کننده کمتر (g/L 5) مورفولوژی یکنواخت تری مشاهده شد. پرونده مقاله

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14 - بررسی شرایط عملیات حرارتی بر استحکام دهی فوم نیکلی تولید شده به روش رسوب دهی الکتروشیمیایی
اکرم صالحی فائزه برزگر احمد مولودی

فوم های فلزی دسته ای از مواد نوین هستند که با توجه به وجود تخلخل در ساختار، خواص منحصر به فردی مانند نسبت سطح به حجم بالا، قابلیت جذب انرژی بالا و نسبت استحکام به وزن بالایی دارند. از میان فوم های فلزی، فوم های نیکلی یکی از پرکاربردترین مواد در ساخت انواع کاتالیست ها، ف چکیده کامل

فوم های فلزی دسته ای از مواد نوین هستند که با توجه به وجود تخلخل در ساختار، خواص منحصر به فردی مانند نسبت سطح به حجم بالا، قابلیت جذب انرژی بالا و نسبت استحکام به وزن بالایی دارند. از میان فوم های فلزی، فوم های نیکلی یکی از پرکاربردترین مواد در ساخت انواع کاتالیست ها، فیلترها و صداخفه کن ها در صنایع مختلف هستند. در این تحقیق فوم نیکلی تخلخل باز به روش رسوب دهی الکتروشیمیایی بر روی زیر لایه ی پلیمری تولید شد. فوم های تولید شده به منظور حذف فوم پلی اورتانِ زیر لایه و افزایش داکتیلیتی تحت عملیات حرارتی تفجوشی در محیط خنثی، در دو دمای ℃ ۶۰۰ و ℃ ۱۰۰۰ قرار گرفتند. بررسی ریزساختار با میکروسکوپ الکترونی روبشی و همچنین آنالیز EDS نمونه ها پس از تفجوشی بیانگر نفوذ اتم های کربن در دمای ℃ ۶۰۰ و اکسیداسیون نمونه ها در دمای ℃ ۱۰۰۰ است. نتایج آزمون فشار نشان دادند که عملیات تفجوشی موجب داکتیل شدن فوم های نیکلی می شود. فرایند داکتیل شدن همراه با کاهش استحکام مسطح از MPa ۷۹/۴ به ۶/۳ و ۶۵/۱ بترتیب برای تفجوشی در دمای ℃ ۶۰۰ و ℃ ۱۰۰۰ است. نتایج بدست آمده، نشان دادند که علی رغم عدم تاثیر عملیات حرارتی بر کرنش چگالش فوم نیکلی، قابلیت جذب انرژی آن ها نیز از MJ/cm2 ۵۱/۱ به ۲۱/۱ و ۵۵/۰ بترتیب برای تفجوشی در دمای ℃ ۶۰۰ و ℃ ۱۰۰۰ کاهش می یابد. پرونده مقاله

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15 - تاثیر متغیرهای آبکاری الکتریکی پالسی و عملیات حرارتی بعدی بر خواص پوشش آلیاژی نانو ساختار کبالت-تنگستن
سمیه اباذری سیوندی سعید رستگاری شهرام خیراندیش

پوشش‌ آلیاژی نانو ساختار کبالت–تنگستن با استفاده از روش آبکاری الکتریکی پالسی با فرکانس Hz 200 از حمام سیتراتی در دمای °C 60 روی زیر لایه فولاد ساده کربنی تهیه گردید. در این تحقیق، تاثیر غلظت سولفات کبالت در حمام و سیکل کاری بر ساختار بلوری، اندازه کریستالیت، چکیده کامل

پوشش‌ آلیاژی نانو ساختار کبالت–تنگستن با استفاده از روش آبکاری الکتریکی پالسی با فرکانس Hz 200 از حمام سیتراتی در دمای °C 60 روی زیر لایه فولاد ساده کربنی تهیه گردید. در این تحقیق، تاثیر غلظت سولفات کبالت در حمام و سیکل کاری بر ساختار بلوری، اندازه کریستالیت، سختی و مقاومت به خوردگی پوشش مورد بررسی قرار گرفت. مورفولوژی سطحی و ترکیب پوشش‌ها با استفاده از میکروسکوپ الکترونی روبشی (SEM) و آنالیز EDS مورد بررسی قرار گرفت. اندازه دانه های کریستالی به کمک آنالیز پراش اشعه ایکس(XRD) و رابطه شرر محاسبه شد. میکروسختی پوشش‌ها با استفاده از دستگاه میکروسختی‌سنج ویکرز اندازه‌گیری شد. بررسی نتایج نشان می‌دهند پوشش آبکاری شده در غلظت سولفات کبالت mol/l2/0 و سیکل کاری %60 با چگالی جریان متوسط A/dm21 پوشش بهینه با سختی معادل Hv 758 بوده است. عملیات حرارتی پوشش آمورف حاصل از چگالی جریان A/dm24 در شرایط خلا بالا سبب کریستالی شدن پوشش می‌شود. مقدار سختی پوشش از Hv 436 قبل از عملیات حرارتی به Hv 1059 پس از عملیات حرارتی در دمای Cº 600 رسید. با افزایش دما تا Cº 600 ساختار پلی کریستال با ترکیبات فازی Co3W و CowO4 شکل گرفت که دلیل افزایش سختی در این دما است. عملیات حرارتی سبب بهبود مقاومت به خوردگی پوشش شده است. پوشش عملیات حرارتی شده در دمایCº 400 کمترین نرخ خوردگی را داشت. پرونده مقاله

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16 - بررسی تأثیر دانسیته جریان اعمالی بر خواص ترشوندگی پوشش سریم اکسید تولید شده به روش رسوب‌دهی الکتروشیمیایی
نوید احمدی زاده پوریا نجفی سیار

در این تحقیق پوشش سریم اکسید به روش رسوب‌دهی الکتروشیمیایی بر روی زیرلایه مس ایجاد شد. تأثیر دانسیته جریان اعمالی بر مورفولوژی، ساختار کریستالی، شیمی سطح، زبری سطح و رفتار ترشوندگی پوشش‌ها به ترتیب به وسیله میکروسکوپ الکترونی روبشی، آزمون تفرق اشعه ایکس، طیف سنجی تبدیل چکیده کامل

در این تحقیق پوشش سریم اکسید به روش رسوب‌دهی الکتروشیمیایی بر روی زیرلایه مس ایجاد شد. تأثیر دانسیته جریان اعمالی بر مورفولوژی، ساختار کریستالی، شیمی سطح، زبری سطح و رفتار ترشوندگی پوشش‌ها به ترتیب به وسیله میکروسکوپ الکترونی روبشی، آزمون تفرق اشعه ایکس، طیف سنجی تبدیل فوریه اشعه مادون قرمز، میکروسکوپ نیروی اتمی و اندازه‌گیری زاویه تماس آب بر روی پوشش‌ها بررسی شدند. نتایج حاصل نشان دادند که با افزایش دانسیته جریان اعمالی پوشش‌هایی ضخیم‌تر با میزان ترک سطحی و زبری بیشتر تولید می‌شوند. همچنین صفحات کریستالی (۰۰۲) در پوشش‌های تولید شده در دانسیته جریان‌های کمتر، رشد بیشتری داشتند و این پوشش‌ها دارای اندازه بلور بزرگ‌تری بودند. با اعمال دانسیته جریان‌های بیشتر، رفتار آبدوستی پوشش‌های سریا بیشتر شد. اگرچه در ابتدا پوشش‌های سریا رفتاری آبدوست داشتند اما پس از قرار گرفتن در معرض هوا و جذب هیدروکربن آبگریز شدند. پوشش‌های ساخته شده در دانسیته جریان‌های بالاتر میزان جذب هیدروکربن بیشتری از خود نشان دادند. پرونده مقاله

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