AND CORROSION PROTECTION OF METALS
Russian Journal of Applied Chemistry, 2012, Vol. 85, No. 4, pp. 604−611.
Pleiades Publishing, Ltd., 2012.
Original Russian Text © G.I. Medvedev, A.A. Rybin, N.A. Makrushin, 2012, published in Zhurnal Prikladnoi Khimii, 2012, Vol. 85, No. 4, pp. 587−594.
Electrodeposition of Tin–Indium Alloy from a Sulfate Electrolyte
in the Presence of Organic Substances
G. I. Medvedev, A. A. Rybin, and N. A. Makrushin
Novomskovsk Institute, Mendeleev Russian University of Chemical Enginering,
Novomoskovsk, Tula oblast, Russia
Received October 11, 2011
Abstract—Electrodeposition of the Sn–In alloy from a sulfate electrolyte in the presence of synthanol, formalin,
and butynediol-1,4 was studied. An electrolyte composition and conditions for obtaining an alloy of prescribed
composition are suggested.
Owing to its good physicomechanical and chemical
properties, the Sn–In electrolytic alloy ﬁ nds use in low-
melting solders, antifriction and wear-resistant coatings,
and sliding contacts with low transition resistance, as
well as in making connections by soldering in assembly
of integrated circuits and micromodules [1–3]. Alloys
with various indium contents have better corrosion
properties in sodium chloride and hydroxide solutions
and in mineral oils.
The Sn–In alloy is commonly electrodeposited
from sulfate, hydrogen boroﬂ uoride, alkaline, citrate,
and tartrate electrolytes [4–13]. Sulfate electrolytes
are the simplest in composition. Published data on the
electrodeposition of the tin–indium alloy from sulfate
solutions are comparatively scarce, with the existing
electrolytes having a narrow range of working current
densities [12, 13].
In this study, we examined the electrodeposition of
the Sn–In alloy from a sulfate electrolyte with organic
The electrodeposition conditions of the Sn–
In alloy were studied in the electrolyte of the
following composition (g l
O 5–90, H
20–200, DS-10 Synthanol
0.5–20; formalin (37% solution) 1–10 ml l
butynediol-1,4 1–15 ml l
. These organic substances
were chosen because, as shown in , DS-10
synthanol, formalin, and butynediol-1,4 favor formation
of bright coatings of tin and its alloys. The study was
carried out at temperatures of 18–50°C in an electrolyte
with and without agitation. The electrolyte was agitated
with a petal rabble.
The indium content of the alloy was determined by
complexonometric titration at pH 5 in the presence of
Xylene Orange indicator at a solution temperature of
80°C . Tin was bound into a complex with tartaric
acid. The content of tin in the alloy was found as
a difference with an error of 3%. The current efﬁ ciency
(CE) by the alloy was determined gravimetrically from
chemical analysis data. Quantum-chemical calculations
were made by the PM3 semi-empirical method [16, 17].
Cathodic polarization curves were measured in
the potentiodynamic mode in a three-electrode cell
with a P-5827 potentiostat at a potential sweep rate
of 5 mV s
. A saturated silver chloride electrode
served as reference. The potentials are given relative
to the standard hydrogen electrode. The overvoltage
of hydrogen evolution on Sn and In was studied in an
electrolyte containing 100 g l
and the additives