Electrodeposition of Polypyrrole Films on 2024 Aluminum Alloy in Phosphoric Acid Solution

2014 ◽  
Vol 775-776 ◽  
pp. 225-229 ◽  
Author(s):  
A.S. Liu ◽  
Thiago Henrique Andrade Xavier ◽  
E.P Cintra ◽  
L.Y. Cho
Keyword(s):  
Aluminum Alloy ◽  
Phosphoric Acid ◽  
Electrochemical Polymerization ◽  
Phosphoric Acid Solution ◽  
Polymeric Chain ◽  
Applied Potential ◽  
2024 Aluminum Alloy ◽  
Polypyrrole Films ◽  
Pyrrole Monomer ◽  
Spherical Grains

Polypyrrole was synthesized onto aluminum surfaces by electrochemical polymerization technique using pyrrole monomer and phosphoric acid in aqueous medium. The influence of applied potential on the morphology of the films was studied by Scanning electron microscopy (SEM). The films displayed a cauliflower-like structure consisting of micro-spherical grains. This structure is related to dopant intercalation in the polymeric chain. The efficiency of these polymeric films to protecting aluminum alloy against corrosion was investigated by potentiodynamic polarization curves. It was also observed that the polymer roughness depend on the applied potential.

scholarly journals Development of Superhydrophilic 6061 Aluminum Alloy by Stepwise Anodization According to Pore-Widening Time

2020 ◽  
Vol 58 (2) ◽  
pp. 97-102
Author(s):  
Youngju Park ◽  
Hyejeong Ji ◽  
Chanyoung Jeong
Keyword(s):  
Aluminum Alloy ◽  
Phosphoric Acid ◽  
Phosphoric Acid Solution ◽  
Water Droplets ◽  
Metallic Substrates ◽  
6061 Aluminum Alloy ◽  
Time Control ◽  
Initial Area ◽  
Pore Widening ◽  
Anodization Process

This study created alumina structures with the highest hydrophilic properties on 6061 aluminum alloy. The anodization process was applied to make various aluminum oxide structures. To create uniform alumina structures on top of a 6061 aluminum alloy surface, after conducting the first anodization in 0.3 M oxalic acid at 40 V at 0 <sup>o</sup>C, the alumina was removed using a mixture of chromic acid and phosphoric acid. Then, secondary and tertiary anodization was performed using the same electrolyte conditions as the primary anodization for 30 minutes at 40 V, respectively. Pore-widening (PW) of oxide film formed after the secondary anodic oxidation was performed for 20, 30, and 40 minutes in 0.1 M phosphoric acid solution. The PW time control allowed various oxide structures to be created, and reduced the area of the outermost surface in contact with water droplets. The smaller the initial area of water droplets, the better the hydrophilic phenomenon. The surface area can be represented as a solid fractional value. Surfaces with solid fraction values of less than or equal to 0.5 were superhydrophilic. This well-controlled anodization process with a pore-widening step can be used to create excellent superhydrophilicity on various metallic substrates, expanding their usefulness and efficacy.

Microstructure Examination of Electromagnetic Casting 2024 Aluminum Alloy Ingots

2007 ◽  
Vol 44 (6) ◽  
pp. 290-298 ◽  
Author(s):  
Aleksandra Pataric ◽  
Zvonko Gulisija ◽  
Srdjan Markovic
Keyword(s):  
Aluminum Alloy ◽  
2024 Aluminum Alloy ◽  
Electromagnetic Casting ◽  
Microstructure Examination

Hole Expansion by Using Al-Alloy Specimen and 0.45% Carbon Steel Specimen

2010 ◽  
Vol 452-453 ◽  
pp. 601-604
Author(s):  
Muhammed Sohel Rana ◽  
Md. Shafiul Ferdous ◽  
Chobin Makabe ◽  
Masaki Fujikawa
Keyword(s):  
Aluminum Alloy ◽  
Fatigue Life ◽  
Carbon Steel ◽  
Cold Work ◽  
Fatigue Crack Initiation ◽  
Steel Specimen ◽  
Expansion Method ◽  
Al Alloy ◽  
2024 Aluminum Alloy ◽  
Cold Worked

The enhancement method of fatigue life and the crack initiate and growth behavior of a holed specimen was investigated by using the 2024 Aluminum alloy and 0.45% Carbon steel. The purpose of present study is to propose a simple technical method for enhancement of fatigue life in a notched specimen. Also, the effect of local plastic deformation by cold work on fatigue crack initiation behavior was examined. This paper presents a basic experimental kinematic cold expansion method by inserting and removing a pin through the specimen hole. The shape of cross-section of pin was a circle or an ellipse. It was shown that the fatigue life of the specimen with the cold-worked hole was longer than that of the specimen with non-cold-worked hole for the case of same stress level in aluminum alloy and carbon steel. Also, the fatigue strength was higher in the case of the cold expanded hole. In this study, a methodology of lengthening of fatigue life of holed specimen is shown. Also, the improvement conditions of fatigue life were significantly affected by shape of pin, local hardening and residual stress conditions. The fatigue life improvement of the damaged component of structures was studied.

Effect of Coating Layer on Advanced Stud Welding of 2024 Aluminum Alloy to Galvanized and Galvannealed Steel Sheet

2014 ◽  
Vol 794-796 ◽  
pp. 351-356
Author(s):  
Yohei Harada ◽  
Kozo Ishizuka ◽  
Shinji Kumai
Keyword(s):  
Aluminum Alloy ◽  
Steel Sheet ◽  
Coating Layer ◽  
Fracture Load ◽  
Tensile Fracture ◽  
2024 Aluminum Alloy ◽  
Steel Sheets ◽  
Sheet Surface ◽  
Stud Welding ◽  
Galvannealed Steel

High strength 2024 aluminum alloy studs were joined to galvanized, galvannealed and non-coated steel sheets by using an advanced stud welding method. Effect of the coating layer on the interfacial microstructure and the tensile fracture load of the joints were evaluated. A specially-designed stud having a circular projection at its bottom was pressed against a sheet surface. A discharge current was introduced from the upper part of the stud. Local heating could be achieved by a high current density at a contact point between the projection and sheet. The observation of joint area revealed the projection was severely deformed and spread along the sheet surface. The coating layer of the galvanized steel sheet was removed at the joint interface under the charging voltage of 200 V, while that of the galvannealed one locally remained on the steel surface even at 400 V. This would be strongly related to the melting or liquidus and solidus temperatures of each coating layer. Joining was not achieved at a low charging voltage in the non-coated and galvannealed steel sheets, while high tensile fracture load was obtained even at 200 V in the galvanized ones.

Effect of precipitate coherency on the corrosion-induced hydrogen trapping in 2024 aluminum alloy

2021 ◽  
Vol 46 (69) ◽  
pp. 34487-34497
Author(s):  
H. Kamoutsi ◽  
G.N. Haidemenopoulos ◽  
H. Mavros ◽  
C. Karantonidis ◽  
P. Floratos ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Hydrogen Trapping ◽  
2024 Aluminum Alloy
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