Porous anodic alumina formed on AA6063 aluminum alloy in a two-step process combining hard and mild anodization

Anodizing, porous anodic alumina, electrochemical impedance spectroscopy, electrolytic coloring, hydrothermal sealing, equivalent electrical circuit, simulation.

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Effect of Concentration of Oxalic Acid on the Synthesis of Porous Anodic Alumina (PAA) on Aluminum Alloy AA6061

Materials Science Forum ◽

10.4028/www.scientific.net/msf.857.281 ◽

2016 ◽

Vol 857 ◽

pp. 281-285

Author(s):

Chun Hong Voon ◽

Bee Ying Lim ◽

K.L. Foo ◽

Uda Hashim ◽

Sung Ting Sam ◽

...

Keyword(s):

Aluminum Alloy ◽

Oxalic Acid ◽

Pore Size ◽

Anodic Alumina ◽

Porous Anodic Alumina ◽

Edx Analysis ◽

Interpore Distance ◽

Ordered Porous

In this study, porous anodic alumina was formed by anodizing of aluminum alloy AA6061 in oxalic acid with concentration ranged from 0.1 M to 1.0 M respectively. AA6061 alloys were anodized at 40 V and 25°C for 60 minutes. FESEM images show that the uniformity of the pores arrangement of porous anodic alumina depends significantly on the concentration of oxalic acid. Well-ordered porous anodic alumina was formed in oxalic acid of 0.3 M, 0.5 M and 0.7 M while disordered porous anodic alumina were formed when the oxalic acid of 0.1 M and 1.0 M were used as electrolytes. EDX analysis revealed that the only peaks corresponding to aluminum and oxygen were detected. Pore size was found to increase with the concentration of oxalic acid while the interpore distance remained almost unchanged although the concentration of oxalic acid increased from 0.1 M to 0.7 M. Atypical anodic alumina without pores arrangement was formed when 1.0 M oxalic acid was used for anodizing.

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Synthesis of Porous Anodic Alumina (PAA) on Aluminum Alloy AA6061 in Mixture of Phosphoric Acid and Oxalic Acid

Materials Science Forum ◽

10.4028/www.scientific.net/msf.857.237 ◽

2016 ◽

Vol 857 ◽

pp. 237-241

Author(s):

Chun Hong Voon ◽

Bee Ying Lim ◽

K.L. Foo ◽

Uda Hashim ◽

Sung Ting Sam ◽

...

Keyword(s):

Aluminum Alloy ◽

Oxalic Acid ◽

Phosphoric Acid ◽

Anodic Alumina ◽

Porous Anodic Alumina ◽

X Ray Diffraction ◽

X Ray ◽

Interpore Distance ◽

Diffraction Patterns ◽

Ordered Porous

In this study, porous anodic alumina was formed on aluminum alloy AA6061 by anodizing using mixture of 0.3 M oxalic acid and phosphoric acid with concentration ranged from 0.1 M to 1.0 M. AA6061 alloys were anodized at 40 V and 25°C for 60 minutes. FESEM images show that the uniformity of the pores arrangement of porous anodic alumina decreased with the increasing concentration of phosphoric acid in the electrolyte. Well-ordered porous anodic alumina was formed in mixture of 0.3 M oxalic acid and 0.1 M phosphoric acid while disordered porous anodic alumina were formed when the concentration of phosphoric acid were in the range of 0.3 M to 1.0 M. Pore size and interpore distance were found to increase with the concentration of phosphoric acid in the mixture. X-ray diffraction patterns show that to γ-Al2O3 were formed on the surface of AA6061 after the anodizing process, regardless of the concentration of phosphoric acid in the mixture electrolyte.

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