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

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.

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

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.

scholarly journals A Novel Method for Fabricating Double Layers Porous Anodic Alumina in Phosphoric/Oxalic Acid Solution and Oxalic Acid Solution

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Yanfang Xu ◽  
Xiaojiu Li ◽  
Hao Liu ◽  
Jie Xu
Keyword(s):  
Oxalic Acid ◽  
Acid Solution ◽  
Oxalic Acid Solution ◽  
Anodic Alumina ◽  
Porous Anodic Alumina ◽  
Double Layers ◽  
Pore Density ◽  
Interpore Distance ◽  
Small Pore ◽  
Novel Method

A novel method for fabricating ordered double layers porous anodic alumina (DL-PAA) with controllable nanopore size was presented. Highly ordered large pore layer with interpore distance of 480 nm was fabricated in phosphoric acid solution with oxalic acid addition at the potential of 195 V and the small pore layer was fabricated in oxalic acid solution at the potential from 60 to 100 V. Experimental results show that the thickness of large pore layer is linearly correlative with anodizing time, and pore diameter is linearly correlative with pore widening time. When the anodizing potential in oxalic acid solution was adjusted from 60 to 100 V, the small pore layers with continuously tunable interpore distance from 142 to 241 nm and pore density from1.94×109to4.89×109 cm−2were obtained. And the interpore distance and the pore density of small pore layers are closely correlative with the anodizing potential. The fabricated DL-PAA templates can be widely utilized for fabrication of ordered nanomaterials, such as superhydrophobic or gecko-inspired adhesive materials and metal or semiconductor nanowires.

Fabrication of highly ordered porous anodic alumina films in 0.75 M oxalic acid solution without using nanoimprinting

2019 ◽  
Vol 111 ◽  
pp. 24-33 ◽  
Author(s):  
Wenqiang Huang ◽  
Mengshi Yu ◽  
Shikai Cao ◽  
Lizhen Wu ◽  
Xiaoping Shen ◽  
...  
Keyword(s):  
Oxalic Acid ◽  
Acid Solution ◽  
Oxalic Acid Solution ◽  
Anodic Alumina ◽  
Porous Anodic Alumina ◽  
Alumina Films ◽  
Ordered Porous

Synthesis of nano-AgI arrays and their optical properties

2001 ◽  
Vol 16 (4) ◽  
pp. 990-992 ◽  
Author(s):  
Yinhai Wang ◽  
Jimei Mo ◽  
Weili Cai ◽  
Lianzeng Yao ◽  
Lide Zhang
Keyword(s):  
Absorption Edge ◽  
Porous Alumina ◽  
X Ray Diffraction ◽  
Alumina Membrane ◽  
X Ray ◽  
Direct Band Gap ◽  
Zinc Blende ◽  
Direct Band ◽  
Diffraction Patterns ◽  
Ordered Porous

Nano-AgI arrays were synthesized by electrochemical double liquor deposition in ordered porous alumina membrane. On the basis of the analysis of x-ray diffraction patterns, the assembly of nano-AgI/Al2O3 is a mixture of a cubic zinc blende type γ–AgI and a hexagonal wurtzite type β–AgI. The visible–ultraviolet optical absorption measuring showed that the assembly only had an absorption edge at 2.82 eV and exhibited the optical features of a semiconductor with a direct band gap. The absorption edge of the assembly was shifted to a shorter wavelength compared with pure γ–AgI and a longer wavelength compared with pure β–AgI. We believed that the change of the absorption edge of the assembly is due to the mixture of γ–AgI and β–AgI.

scholarly journals Effect of Manganese Content on the Fabrication of Porous Anodic Alumina

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
C. H. Voon ◽  
M. N. Derman ◽  
U. Hashim
Keyword(s):  
Pore Diameter ◽  
Chromic Acid ◽  
Cell Structure ◽  
Manganese Content ◽  
Single Step ◽  
Anodic Alumina ◽  
Porous Anodic Alumina ◽  
Secondary Phases ◽  
Interpore Distance ◽  
Ordered Porous

The influence of manganese content on the formation of well-ordered porous anodic alumina was studied. Porous anodic alumina has been produced on aluminium substrate of different manganese content by single-step anodizing at 50 V in 0.3 M oxalic acid at 15°C for 60 minutes. The well-ordered pore and cell structure was revealed by subjecting the porous anodic alumina to oxide dissolution treatment in a mixture of chromic acid and phosphoric acid. It was found that the manganese content above 1 wt% impaired the regularity of the cell and pore structure significantly, which can be attributed to the presence of secondary phases in the starting material with manganese content above 1 wt%. The pore diameter and interpore distance decreased with the addition of manganese into the substrates. The time variation of current density and the thickness of porous anodic alumina also decreased as a function of the manganese content in the substrates.

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