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Indian Journal of Chemical Technology (IJCT) >
IJCT Vol.12 [2005] >
IJCT Vol.12(4) [July 2005] >
| Title: | Corrosion behaviour of electrochemically joined aluminum and stainless steel |
| Authors: | Sheela, G
Muralidharan, V S
Pushpavanam, Malathy |
| Keywords: | Electrochemical joining
mass loss
corrosion current
galvanic couple
polarization technique |
| Issue Date: | Jul-2005 |
| Publisher: | CSIR |
| IPC Code: | G01N17/02; C23F11/00 |
| Abstract: | Two dissimilar metals viz., aluminum and stainless steel (SS)
were joined electrochemically by heavy nickel deposition. Potential-time
behavior, Tafel extrapolation method and galvanic coupling experiments were
conducted to study the corrosion behavior of the three individual metals in 5%
aqueous sodium chloride acidified with acetic acid, alone and in combination.
The systems behaved differently in simple immersion test and on coupling with
each other. In simple immersion test, nickel and SS were nobler to aluminum.
Coupling of aluminum and nickel (bi-metallic) resulted in dissolution of both
metals, the rate of nickel being lower. Potentiodynamic polarization
experiments showed that the aluminum-SS bi-metallic system has the highest
corrosion rate than aluminum-Ni or SS-nickel. Aluminum exhibits pitting type
corrosion when coupled to nickel. Experiments with electroplated specimens and
SEM analysis confirmed that in aluminum-nickel couple both metals corrode, the
corrosion of nickel being considerably lower. Formation of elemental nickel on
aluminum surface also confirmed the above result. |
| Page(s): | 466-471 |
| ISSN: | 0975-0991 (Online); 0971-457X (Print) |
| Source: | IJCT Vol.12(4) [July 2005]
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