Russian Journal of Applied Chemistry, 2010, Vol. 83, No. 2, pp. 263−266.
Pleiades Publishing, Ltd., 2010.
Original Russian Text
Z.R. Obidov, I.N. Ganiev, B.B. Eshov, I.T. Amonov, 2010, published in Zhurnal Prikladnoi Khimii, 2010, Vol. 83, No. 2,
AND CORROSION PROTECTION OF METALS
Corrosion-Electrochemical, and Physicochemical Properties
of Al + 2.18% Fe Alloy Alloyed with Indium
Z. R. Obidov, I. N. Ganiev, B. B. Eshov, and I. T. Amonov
Nikitin Institute of Chemistry, Academy of Sciences of the Republic of Tajikistan, Dushanbe, Tajikistan
Received December 11, 2008
Abstract—Results of investigations of corrosion-electrochemical, and thermal properties of Al + 2.18% Fe alloy
alloyed with indium were reported.
Because the selling price of poor-grade aluminum
is low, plants manufacturing aluminum with increased
content of iron suffer losses. The problem of development
of alloys based on a metal of this kind remains topical. As
is known, iron strongly impairs the corrosion resistance
and plasticity of aluminum.
Puriﬁ cation of aluminum to remove iron by ﬁ ltration
and other methods is a labor-consuming and expensive
procedure. Therefore, we consider in this study an
alternative variant of using technical-grade aluminum
with increased content of iron: development of alloys
based on the aluminum–iron system. Indium can be used
as an alloying element for this purpose because there have
been reports in the literature about its positive inﬂ uence
on the electrical properties and activation of technical-
The goal of our study was to examine the effect
of indium additions on the corrosion-electrochemical
behavior and physicochemical properties of the Al +
2.18% Fe alloy.
We used aluminum of A76 brand, iron of analytically
pure grade, and indium of In00 brand as object of study.
Alloys were produced from these metals in alumina
crucibles in a shaft furnace of the SShOL type in the
temperature range 900–1100°C. The resulting alloys were
cast into a graphite mold to obtain rods 8 mm in diameter
and 140 mm long. The nonworking surface of the samples
was insulated with a tar composed of a 50 : 50 (%)
mixture of rosin and parafﬁ n. The study was performed
with a PI-50.1.1 potentiostat in the potentiodynamic
mode at a potential sweep rate of 2 mV s
. Before being
submerged into a working NaCl solution, the sample
edge was cleaned with emery paper, polished, degreased,
etched in a 10% NaOH solution, and thoroughly washed
with ethanol. The solution temperature in the cell was
maintained constant (20°C) with an MLSh8 thermostat.
A silver chloride electrode served as reference, and
platinum wire as auxiliary electrode.
The corrosion-electrochemical behavior of the Al +
2.18% Fe alloy alloyed with indium was studied in
0.03, 0.3, and 3% sodium chloride solutions, using the
procedure described in . In electrochemical studies,
the samples were potentiodynamically polarized in the
positive direction from the potential attained on their
being submerged, until the current steeply increased as
a result of pitting. Then the samples were polarized in
the reverse direction to a potential of –1400 mV, with
the result that the near-electrode layer was alkalized.
Further, the samples were again polarized in the positive
The corrosion current, the main electrochemical
parameter of the corrosion process, was calculated
from the cathodic curve, with the Tafel coefﬁ cient b
0.124 V taken into account because the pitting corrosion
of aluminum and its alloys in neutral media is controlled
by the cathodic reaction of oxygen ionization .
The chemical composition and data on the corrosion-