Study the effect of adding aluminum powder on anodizing efficiency

Dissertant

Salih, Adi Sami Muhammad

University

University of Technology

Faculty

-

Department

Department of Production Engineering and Metallurgy

University Country

Iraq

Degree

Master

Degree Date

2007

English Abstract

Pure aluminum and aluminum alloy (6063) have been anodized using sulfuric acid as an electrolyte.

To study the characteristic of the anodic film, four variables, which were considered as the most dominant variables, were studied- These variables are : current density in the range of 1- 4 A / dm., electrolyte concentration in the range of 6-20 vol.

%, electrolyte temperature in the range of 10- 30°C and anodizing time between 12-60 min.

These four variables are manipulated through the experimental work using Box - Wilson experimental design where second order polynomial model was proposed to correlate the studied variables with the thickness of anodic film of pure aluminum and aluminum alloy (6063) to estimate the coefficients of the proposed polynomial adopted via statistics software.

The predicated models are found after statistically analyzing the significance as follows : For pure aluminum : Y = 29.5525 + 7.968IX, 0.1226 X r 0.6184X3 + 8.1107X4- 0.9512XV 0.8762 x, -1, 4199 XV 0.4837XV1-321 OXtXr 0.8885 X [X3 + 2.1975X, XrL2723X2X3 -1.419 SX2X„- 0.2848X3X„ For aluminum allov (6063): Y= 27.7800+8.0737X, - 0.

J987Xr 0.8037X3+8.2078X4- 0.6994XV 0.8882X,' h5582XV0.3482XVll231X, Xr0, 508lX1X3 + 2.6225XiV1.7931X2X3 -1.6956 X2X4- 1.0581X3X4 where Y is the objective function (thickness of anodic film), X] is the current density; X2 is the electrolyte concentration; X3 is the temperature of electrolyte and X4 is the anodizing time.

The study shows that the anodizing time and current density show positive dependence of great significance on the anodic film thickness while the other two studied variables (i.e.

concentration and temperature of electrolyte) show little dependence on the film thickness of pure aluminum and aluminum alloy (6063).

Optimum conditions for achieving the maximum film thickness are obtained from optimizing the above correlation and are found as follows : Pure aluminum aluminum alloy (6063) Current density (A / dm2) 4, 4 Acid concentration (vol, %) 6, 6 Electrolyte temperature TQ 19, 19.5 Time of anodizing (min,) 60, 60 Different amounts of aluminum powder (5, 7, 9 and 11 g / 1) were added to If uric acid solution of the specimens under optimum conditions and the gcct of these additions was studied to find out the benefit to anodizing Aluminum powder additions to retard the dissolution of the anodic film formation on the anode.

The specimens were examined in different conditions using optical microscope, roughness and hardness measurements.

The study shows the anodizing process was improved by adding aluminum powder with optimum conditions and the best value of aluminum powder was 9g / J, where the thickness improved from 72.25pm at optimum conditions to 8l.25u.in with adding 9g / I aluminum powder and the coating ratio improved from 1.481 at optimum conditions to i .541 with adding 9g / l aluminum powder for pure aluminum, white the thickness improved from 74.56pm at optimum conditions to 82.29pm with adding 9 g/l aluminum powder and the coating ratio improved from 1.417 at optimum conditions to 1.471 with adding 9g / L aluminum powder for aluminum alloy (6063).

The study also shows that the effective anodic current efficiency was increased about 12.50 % when adding aluminum powder of 9g / l compared with optimum conditions for pure aluminum, while this value was increased about 10.20 % when adding aluminum powder of 9g / l compared with optimum conditions for aluminum alloy (6063).

It is found that the surface roughness of specimens is about 0.080 urns and 0.090 pm for pure aluminum and aluminum alloy (6063) respectively with adding aluminum powder of 9g / l gives the best result compared with the specimens at optimum conditions and bare specimens.

While hardness value of specimens is about 274HV and 2S8 HV for pure aluminum and aluminum alloy (6063) respectively with adding aluminum powder of 9g / 1 gives the best result compared with the specimens at optimum conditions and bare specimens.

Main Subjects

Materials Science , Minerals

Topics

• Minerals
• Aluminum alloys

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-305648