The Mediated Electrodeposition of Polypyrrole on Aluminium Alloy

2005 ◽  
Vol 58 (4) ◽  
pp. 294 ◽  
Author(s):  
Kirill L. Levine ◽  
Dennis E. Tallman ◽  
Gordon P. Bierwagen
Keyword(s):  
Aluminium Alloy ◽  
Deposition Potential ◽  
Disodium Salt ◽  
Film Deposition ◽  
Mediation Process ◽  
Al Alloy ◽  
Initial Work ◽  
Direct Electrodeposition ◽  
Electron Transfer Mediation ◽  
Benzene Compounds

The direct electrodeposition of conjugated polymers onto active metals such as aluminium and its alloys is complicated by the concomitant oxidation of the metal that occurs at the positive potential required for polymer formation/deposition. We have developed an approach that uses electron transfer mediation to reduce the deposition potential of polypyrrole on aluminium and aluminium alloy by nearly 500 mV, permitting film deposition from aqueous solution with nearly 100% current efficiency. The mediator used in this initial work was 4,5-dihydroxy-1,3-benzenedisulfonate (DHBDS, disodium salt), which also served as the dopant or counter ion in the polymer. To better understand the mediation process, a series of substituted benzene compounds have been explored for their mediating properties. From these studies, we conclude that both the hydroxyl and the sulfonate functionalities of DHBDS appear to play a role in the mediated electrodeposition at aluminium alloy. New mediators for the electrodeposition of polypyrrole on Al alloy are suggested.

scholarly journals Corrosion of the Welded Aluminium Alloy in 0.5 M NaCl Solution. Part 2: Coating Protection

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2177 ◽  
Author(s):  
Andrey Gnedenkov ◽  
Sergey Sinebryukhov ◽  
Dmitry Mashtalyar ◽  
Igor Vyaliy ◽  
Vladimir Egorkin ◽  
...  
Keyword(s):  
Aluminium Alloy ◽  
Welded Joint ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Weld Interface ◽  
Open Circuit ◽  
Al Alloy ◽  
Protective Properties ◽  
Coating Formation ◽  
Electrode Technique

The high electrochemical activity of the aircraft 1579 aluminium alloy with a welded joint and the necessity of the coating formation to protect this material against corrosion as well as to increase the stability of the weld interface in the corrosive medium has been previously established. In this work, two suggested methods of protective coating formation based on plasma electrolytic oxidation (PEO) in tartrate-fluoride electrolyte significantly increased the protective properties of the welded joint area of the 1579 Al alloy. The electrochemical properties of the formed surface layers have been investigated using SVET (scanning vibrating electrode technique) and SIET (scanning ion-selective electrode technique), EIS (electrochemical impedance spectroscopy), OCP (open circuit potential), and PDP (potentiodynamic polarization) in 0.5 M NaCl. The less expressed character of the local electrochemical processes on the welded 1579 Al alloy with the composite coating in comparison with the base PEO-layer has been established. Polymer-containing coatings obtained using superdispersed polytetrafluoroethylene (SPTFE) treatment are characterized by the best possible protective properties and prevent the material from corrosion destruction. Single SPTFE treatment enables one to increase PEO-layer protection by 5.5 times. The results of this study indicate that SVET and SIET are promising to characterize and to compare corrosion behaviour of coated and uncoated samples with a welded joint in chloride-containing media.

Accumulative Roll Bonding of 7075 Aluminium Alloy at High Temperature

2010 ◽  
Vol 638-642 ◽  
pp. 1929-1933 ◽  
Author(s):  
P. Hidalgo ◽  
C.M. Cepeda-Jiménez ◽  
O.A. Ruano ◽  
F. Carreño
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Aluminium Alloy ◽  
Accumulative Roll Bonding ◽  
Dynamic Recovery ◽  
Rolling Texture ◽  
Al Alloy ◽  
Roll Bonding ◽  
Fibre Texture ◽  
Grain Sizes

The 7075 Al alloy was processed by accumulative roll bonding (ARB) at 300, 350 and 400 °C. The microstructure and texture were characterized and the hardness was measured. Cell/(sub)grain sizes less than 500 nm and typical β-fibre rolling texture were observed in the three ARBed samples. At 400 °C, the presence of elements in solid solution leads to a poorly misoriented microstructure and to a homogeneous β-fibre texture. At 300 and 350 °C highly misoriented microstructure and heterogeneous β-fibre rolling texture are observed, especially at 350 °C, wherein the degree of dynamic recovery is higher. Hardness of the ARBed samples is affected by the amount of atoms in solid solution at the different processing temperatures.

Surface Characterization of an Extruded 6060 Al Alloy

2007 ◽  
Vol 29-30 ◽  
pp. 67-70
Author(s):  
Wei Zhang ◽  
Jim Metson ◽  
C.L. Nguyen ◽  
S. Chen
Keyword(s):  
Aluminium Alloy ◽  
Photoelectron Spectroscopy ◽  
Surface Characterization ◽  
Extrusion Direction ◽  
Surface Characteristics ◽  
Al Alloy ◽  
X Ray ◽  
Film Instability ◽  
Mg Content

The surface characteristics of an extruded 6060 aluminium alloy were investigated with X-ray Photoelectron Spectroscopy (XPS). The results revealed that the extruded surface was covered by oxides of aluminium and magnesium. The thickness of aluminium oxide was found to change along the extrusion direction with the thinnest and thickest oxide at the beginning and end of the extrudate, respectively. Magnesium segregation was found on the surface of the extrusion with the highest and lowest Mg concentration at the beginning and end of the extrudate, respectively. This is the inverse result of that expected where increasing Mg content was believed to be associated with film instability and thicker films.

Effects of Filler Compositions on Mechanical and Physical Properties of the Dissimilar Resistance Spot Welded between Aluminium Alloy and Carbon Steel

2015 ◽  
Vol 656-657 ◽  
pp. 422-427
Author(s):  
Yustiasih Purwaningrum ◽  
Triyono ◽  
Muhammad Fathan
Keyword(s):  
Carbon Steel ◽  
Weld Metal ◽  
Physical Properties ◽  
Aluminium Alloy ◽  
Base Metal ◽  
Testing Machine ◽  
Optical Microscope ◽  
Filler Materials ◽  
Al Alloy ◽  
Resistance Spot

The resistance spot weld (RSW) of dissimilar materials betweeen steel and aluminium is generally more complex than that of similar materials due to the extreme differences in the mechanical, physical and chemical properties of the base metals. This study proposed the use of filler material to connect the differences of their properties. Al-Alloy 5083 with thickness of 4 mm and 1.2 mm thick carbon steel SS400 were joined in lap joint types using RSW with the filler materials. The filler materials were a mixture of steel and aluminium in which weight composition variations (Fe:Al) were 90:10; 70:30; 30:70 and 90:10 in percent. The physical properties were examined based on the microstructure using optical microscope while the mechanical properties were measured with respect to the strength and hardness using Universal Testing Machine and Vickers Microhardness respectively. Results showed that weld metals with filler composition of 70:30% had highest shear-strength. The microstructure examinations showed that Microstructure of base metal and HAZ carbon steel was ferrite and perlite while that of weld metal was bainite. There were no significant differences in the microstructures and the hardness of weld metal, HAZ, and the base metal of aluminium alloy-5083 due to nonheat-treatable material.

Structure and Property of Micro Arc Oxidation Ceramic Coatings on Al Alloy in K2ZrF6 Solution

2010 ◽  
Vol 105-106 ◽  
pp. 505-508 ◽  
Author(s):  
Zhen Dong Wu ◽  
Zhong Wen Yao ◽  
Fang Zhou Jia ◽  
Zhao Hua Jiang
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Aluminium Alloy ◽  
Friction And Wear ◽  
Ceramic Coatings ◽  
Al Alloy ◽  
Structure And Property ◽  
Micro Arc Oxidation ◽  
Disk Friction ◽  
Composition Structure

The coatings containing zirconia were produced on LY12 Aluminium alloy by micro-arc oxidation in K2ZrF6 and NaH2PO2 solution. The composition, structure, hardness, friction and wear resistance and corrosion resistance of the coating were studied by XRD, SEM, EDS, ball-on-disk friction tester and electrochemical analyzer, respectively. The results show that coating was composed of m-ZrO2 and t-ZrO2. There were a large amount of Zr and O and a little Al, P and K in the coating. The thickness of coating prepared for 3h was 168μm and the maximum value of the hardness was up to 16.75GPa. The friction and wear resistance and corrosion resistance were improved, compared with the LY12 aluminium alloy substrate.

Mechanical Behaviour of an AA6082 Aluminium Alloy at Low Temperatures

2014 ◽  
Vol 794-796 ◽  
pp. 532-537 ◽  
Author(s):  
Ida Westermann ◽  
Odd Sture Hopperstad ◽  
Magnus Langseth
Keyword(s):  
Aluminium Alloy ◽  
Work Hardening ◽  
Aluminium Alloys ◽  
Room Temperature ◽  
Area Reduction ◽  
Work Hardening Rate ◽  
Different Temperatures ◽  
Tensile Data ◽  
Initial Work ◽  
Marine Applications

Aluminium alloys are known to have good cryogenic properties. However, little work is reported on aluminium alloys in the temperature range from room temperature and down to-100°C, which are likely operating temperatures in arctic regions. This work is an experimental study of the low temperature mechanical properties of an extruded AA6082 aluminium alloy in the T6 condition approved for marine applications. Quasi-static and dynamic tensile testing has been carried out at different temperatures from room temperature and down to-70°C. This decrease in temperature leads to a 10 % increase in yield strength. No significant influence of temperature was found on the area reduction to fracture. The work-hardening behaviour has been analysed for different temperatures and strain rates by fitting a generalized Voce rule to the tensile data. The initial work-hardening rate is found to depend weakly on the temperature and strain rate.

Optimisation of mercury film deposition on glassy carbon electrodes: evaluation of the combined effects of pH, thiocyanate ion and deposition potential

2004 ◽  
Vol 503 (2) ◽  
pp. 203-212 ◽  
Author(s):  
Sandra C.C Monterroso ◽  
Helena M Carapuça ◽  
João E.J Simão ◽  
Armando C Duarte
Keyword(s):  
Glassy Carbon ◽  
Deposition Potential ◽  
Film Deposition ◽  
Carbon Electrodes ◽  
Combined Effects ◽  
Glassy Carbon Electrodes ◽  
Thiocyanate Ion ◽  
Mercury Film ◽  
Effects Of Ph

A Novel Process for Fabricating Aluminium Alloy Porous Structure for Possible Application in Antimicrobial Filtration

2015 ◽  
Vol 828-829 ◽  
pp. 359-365 ◽  
Author(s):  
Agripa Hamweendo ◽  
Ionel Botef
Keyword(s):  
Drinking Water ◽  
Porous Structure ◽  
Aluminium Alloy ◽  
Metal Foam ◽  
Al Alloy ◽  
Cu Alloy ◽  
Contaminated Drinking Water ◽  
Micro Organisms ◽  
Water Borne ◽  
Alloy Metal

This paper presents a novel process for fabricating micro-porous Aluminium (Al) alloy structures with possible application in antimicrobial filtration of drinking water which is contaminated with pathogenic micro-organisms responsible for water-borne diseases. This process is an integration of cold spray (CS) with the alloy-de-alloy phenomenon. In this process, the Al, Aluminium oxide () and Copper (Cu) powders with antimicrobial capabilities were mixed and deposited directly onto to a substrate using CS. To create porosity in the Al-Alumina-Cu coating, pores were innovatively engineered by alloying the Al--Cu with pore forming agents followed by preferential de-alloyed of these agents. The resulting structures have promising microstructural composition and porosity which make them favourable for antimicrobial filtration of contaminated drinking water. Consequently, this research demonstrates that via CS, a novel process was developed for fabricating porous Al-Alumina-Cu alloy metal foam for application in decontamination of drinking water.

The formation of a hydrotalcite coating on the aluminium alloy 6060 using a spray system

Clay Minerals ◽  
2015 ◽  
Vol 50 (5) ◽  
pp. 583-592 ◽  
Author(s):  
Lingli Zhou ◽  
Henrik Friis ◽  
Melanie Roefzaad ◽  
Kasper Bondo Hansen ◽  
Sara Eisenhardt ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Aluminium Alloy ◽  
Layer Structure ◽  
Salt Spray ◽  
Al Alloy ◽  
Acetate Solution ◽  
Average Thickness ◽  
Spray System ◽  
Filiform Corrosion ◽  
Better Than

AbstractCoatings with the composition of Li-Al-NO3 hydrotalcite were formed on the Al alloy 6060 using a spray system. The coatings consist of crystals with a typical hydrotalcite structure. Dense, uniform and blade-like flakes cover completely the surface of the Al substrate. The coatings display a multi-layer structure with average thickness of ∼1000 nm. The hydrotalcite-coated samples performed better than those without coatings in salt-spray and filiform-corrosion tests, and further treatment involving sealing with a Mg acetate solution and dipping in a H2O2 + Ce-based solution improved the corrosion resistance ability.

Hot Extrusion of Nanostructured Al Alloy Powder: Extrusion Ratio and Temperature Effect on the Microstructure and Mechanical Properties

2008 ◽  
Vol 570 ◽  
pp. 91-96
Author(s):  
M.M. Peres ◽  
J.B. Fogagnolo ◽  
Fernando Audebert ◽  
F. Saporiti ◽  
Alberto Moreira Jorge ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminium Alloy ◽  
Alloy Powder ◽  
Bulk Material ◽  
Hot Extrusion ◽  
Extrusion Ratio ◽  
Al Alloy ◽  
Gas Atomization ◽  
Processing Conditions ◽  
Compressive Tests

A nanostructured aluminium alloy powder, prepared by rapid solidification via gas atomization, was consolidated into bulk material under various processing conditions via hot extrusion. The microstructure modifications and mechanical properties of the consolidated alloys as a function of the extrusion conditions were investigated. The increase in the extrusion-load with the increase of extrusion-rate and decrease of temperature are shown and discussed in association with the modification in the microstructures. The differences in mechanical properties measured by compressive tests are also discussed in association with the extrusion parameters. Furthermore, suggestions are given for rationalising the extrusion ratio and temperature conditions for the consolidation of nanostructured aluminium alloy powders via hot extrusion.

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